IS-IS

IS-IS Configuration Commands
Generic Commands
shutdown
Syntax[no] shutdown

Context

config>router>isis
config>router>isis>interface ip-int-nameconfig>router>isis>if>level level-number
config>router>isis>if>segment-routing

Description

This command administratively disables an entity. When disabled, an entity does not change, reset, or
remove any configuration settings or statistics.
The operational state of the entity is disabled as well as the operational state of any entities contained within.
Many objects must be shut down before they may be deleted.
The no form of this command administratively enables an entity.

Special Cases

IS-IS Global — In the config>router>isis context, the shutdown command disables the IS-IS protocol
instance. By default, the protocol is enabled, no shutdown.
IS-IS Interface — In the config>router>isis>interface context, the command disables the IS-IS interface.
By default, the IS-IS interface is enabled, no shutdown.
IS-IS Interface and Level — In the config>router>isis>interface ip-int-name>level context, the command disables the IS-IS interface for the level. By default, the IS-IS interface at the level is enabled, no
shutdown.

Default

no shutdown — IS-IS entity is administratively enabled.

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IS-IS Commands
isis
Syntax[no] isis [isis-instance]

Context

config>router

Description

This command creates the context to configure the Intermediate-System-to-Intermediate-System (IS-IS) protocol instance.
The IS-IS protocol instance is enabled with the no shutdown command in the config>router>isis context.
Alternatively, the IS-IS protocol instance is disabled with the shutdown command in the config>router>isiscontext.
The no form of the command deletes the IS-IS protocol instance. Deleting the protocol instance removes all
configuration parameters for this IS-IS instance.

Parametersisis-instance — Specifies the instance ID for an IS-IS instance.
Values

1–31

Default0tag
Syntaxtag tagno tagContext

config>router>isis>interface

Description

This command configures a route tag to the specified IP address of an interface.

Parameters

tag — Assigns a route tag.
Values

1 — 4294967295

all-l1isis
Syntaxall-l1isis ieee-address
no all-l1isis

Context

config>router>isis

Description
Default

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This command enables you to specify the MAC address to use for all L1 IS-IS routers. The MAC address
should be a multicast address. You should shut/no shut the IS-IS instance to make the change operational.
all-l1isis 01-80-C2-00-01-00

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IS-ISParametersieee-address — Specifies the destination MAC address for all L1 I-IS neighbors on the link for this IS-IS
instance.

all-l2isis
Syntaxall-l2isis ieee-address
no all-l2isis

Context

config>router>isis

Description
Default
Parameters

This command enables you to specify the MAC address to use for all L2 IS-IS routers. The MAC address
should be a multicast address. You should shut/no shut the IS-IS instance to make the change operational.
all-l2isis 01-80-C2-00-02-11
ieee-address — Specifies the destination MAC address for all L2 IS-IS neighbors on the link for this IS-IS
instance.

authentication-check
Syntax[no] authentication-check

Context

config>router>isis

Description

This command sets an authentication check to reject PDUs that do not match the type or key requirements.
The default behavior when authentication is configured is to reject all IS-IS protocol PDUs that have a mismatch in either the authentication type or authentication key.
When no authentication-check is configured, authentication PDUs are generated and IS-IS PDUs areauthenticated on receipt. However, mismatches cause an event to be generated and will not be rejected.
The no form of this command allows authentication mismatches to be accepted and generate a log event.

Default

authentication-check — Rejects authentication mismatches.

authentication-key
Syntaxauthentication-key [authentication-key | hash-key] [hash | hash2]
no authentication-key

Context

config>router>isis
config>router>isis>level level-number

Description

This command sets the authentication key used to verify PDUs sent by neighboring routers on the interface.
Neighboring routers use passwords to authenticate PDUs sent from an interface. For authentication to work,
both the authentication key and the authentication type on a segment must match. The authentication-typestatement must also be included.

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To configure authentication on the global level, configure this command in the config>router>isis context.
When this parameter is configured on the global level, all PDUs are authenticated including the hello PDU.
To override the global setting for a specific level, configure the authentication-key command in the config>router>isis>level context. When configured within the specific level, hello PDUs are not authenticated.
The no form of the command removes the authentication key.
Default
Parameters

no authentication-key — No authentication key is configured.
authentication-key — The authentication key. The key can be any combination of ASCII characters up to
255 characters in length (un-encrypted). If spaces are used in the string, enclose the entire string in quotation marks (“ ”).
hash-key — The hash key. The key can be any combination of ASCII characters up to 342 characters inlength (encrypted). If spaces are used in the string, enclose the entire string in quotation marks (“ ”).
This is useful when a user must configure the parameter, but, for security purposes, the actual
unencrypted key value is not provided.
hash — Specifies the key is entered in an encrypted form. If the hash parameter is not used, the key isassumed to be in a non-encrypted, clear text form. For security, all keys are stored in encrypted form in
the configuration file with the hash parameter specified.
hash2 — Specifies the key is entered in a more complex encrypted form. If the hash2 parameter is not used,
the less encrypted hash form is assumed.

authentication-type
Syntaxauthentication-type {password | message-digest}
no authentication

Context

config>router>isis
config>router>isis>level level-number

Description

This command enables either simple password or message digest authentication or must go in either the
global IS-IS or IS-IS level context.
Both the authentication key and the authentication type on a segment must match. The authentication-key
statement must also be included.
Configure the authentication type on the global level in the config>router>isis context.
Configure or override the global setting by configuring the authentication type in the config>router>isis>level context.
The no form of the command disables authentication.

Default
Parameters

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no authentication-type — No authentication type is configured and authentication is disabled.
password — Specifies that simple password (plain text) authentication is required.

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message-digest — Specifies that MD5 authentication in accordance with RFC2104 is required.

auth-keychain
Syntaxauth-keychain nameContext

config>router>isis>config>router>isis>level
config>service>vprn>isis>config>service>vprn>isis>level

Description
Default
Parameters

This command configures an authentication keychain to use for the protocol interface. The keychain allows
the rollover of authentication keys during the lifetime of a session.
no auth-keychainname — Specifies the name of the keychain, up to 32 characters, to use for the specified protocol session or
sessions.

hello-auth-keychain
Syntax

hello-auth-keychain nameContext

config>router>isis
config>router>isis>level
config>service>vprn>isis>interface
config>service>vprn>isis>interface>level

Description
Default
Parameters

This command configures an authentication keychain to use for the protocol interface. The keychain allows
the rollover of authentication keys during the lifetime of a session.
no hello-auth-keychainname — Specifies the name of the keychain, up to 32 characters, to use for the specified protocol session or
sessions.

default-route-tag
Syntaxdefault-route-tag tag
no default-route-tag

Context

config>router>isis

Description

This command configures the route tag for default route.

Parameters

tag — Assigns a default tag.
Values

1 — 4294967295

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csnp-authentication
Syntax[no] csnp-authentication

Context

config>router>isis
config>router>isis>level level-number

Description

This command enables authentication of individual IS-IS packets of complete sequence number PDUs(CSNP) type.
The no form of the command suppresses authentication of CSNP packets.

csnp-interval
Syntaxcsnp-interval seconds
no csnp-interval

Context

config>router>isis>interface ip-int-name

Description

This command configures the time interval, in seconds, to send complete sequence number (CSN) PDUs
from the interface. IS-IS must send CSN PDUs periodically.
The no form of the command reverts to the default value.

Default

csnp-interval 10 — CSN PDUs are sent every 10 seconds for LAN interfaces.
csnp-interval 5 — CSN PDUs are sent every 5 seconds for point-to-point interfaces.

Parameters

seconds — The time interval, in seconds between successive CSN PDUs sent from this interface expressed
as a decimal integer.
Values

1 — 65535

link-group
Syntaxlink-group link-group-nameno link-groupContext

config>router>isis

Description

This command specifies the IS-IS link group associated with this particular level of the interface.

Parameterslink-group-name — Specifies an IS-IS link group on the system up to 32 characters in length.

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description
Syntaxdescription string
no description

Context

config>router>isis>link-group

Description

This command adds a description string to the associated link-group. The string can be up to 256 characterslong and can only contain printable characters. If the command is issued in the context of a link-group that
already contains a description then the previous description string is replaced.
The no form of the command removes the description from the associated link-group.

Parameters

string — Character string to be associated with the associated link-group.

memberSyntax[no] member interface-nameContext

config>router>isis>link-group

Description

This command adds or removes a links to the associated link-group. The interface name should alreadyexist before it is added to a link-group.
The no form of the command removes the specified interface from the associated link-group.

Parametersinterface-name — Name of the interface to be added or removed from the associated link-group.

oper-members
Syntaxoper-members [0-8]
no oper-members

Context

config>router>isis>link-group

Description

This command sets the threshold for the minimum number of operational links for the associated link-group.
If the number of operational links drops below this threshold, the configured offsets are applied. For example, oper-members=3. The metric of the member interfaces is increased when the number of interfaces islower than 3.
The no form of the command reverts the oper-members limit to 1.

Default

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revert-members
Syntaxrevert-members [0-8]
no revert-members

Context

config>router>isis>link-group

Description

This command sets the threshold for the minimum number of operational links to return the associated linkgroup to its normal operating state and remove the associated offsets to the IS-IS metrics. If the number ofoperational links is equal to or greater than the configured revert-member threshold then the configured offsets are removed.
The no form of the command reverts the revert-members threshold back to the default which is equal to theoper-member threshold value.

Default

revert-members oper-members

ipv4-unicast-metric-offset
Syntaxipv4-unicast-metric-offset offset-value
no ipv4-unicast-metric-offset

Context

config>router>isis>link-group

Description

This command sets the offset value for the IPv4 unicast address family. If the number of operational links
drops below the oper-members threshold, the configured offset is applied to the interface metric.
The no form of the command reverts the offset value to 0.

Default
Parameters

no ipv4-unicast-metric-offset
offset-value — Specifies the amount the interface metric for the associated address family is to be increased
if the number of operational members in the associated link-group drops below the oper-members
threshold.
Values

0 — 6777215

ipv6-unicast-metric-offset
Syntaxipv6-unicast-metric-offset offset-value
no ipv6-unicast-metric-offset

Context

config>router>isis>link-group

Description

This command sets the offset value for the IPv6 unicast address family. If the number of operational links
drops below the oper-members threshold, the configured offset is applied to the interface metric for the
IPv6 topology.
The no form of the command reverts the offset value to 0.

Default

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no ipv6-unicast-metric-offset

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IS-ISParameters

offset-value — Specifies the amount the interface metric for the associated address family is to be increased
if the number of operational members in the associated link-group drops below the oper-members
threshold.
Values

0 — 6777215

ipv4-multicast-metric-offset
Syntaxipv4-multicast-metric-offset offset-value
no ipv4-multicast-metric-offset

Context

config>router>isis>link-group

Description

This command sets the offset value for the IPv4 multicast address family. If the number of operational links
drops below the oper-members threshold, the configured offset is applied to the interface metric for the IPv4
multicast topology
The no form of the command reverts the offset value to 0.

Default
Parameters

no ipv4-multicast-metric-offset
offset-value — Specifies the amount the interface metric for the associated address family is to be increased
if the number of operational members in the associated link-group drops below the oper-members
threshold
Values

0 — 6777215

ipv6-multicast-metric-offset
Syntaxipv6-multicast-metric-offset offset-value
no ipv6-multicast-metric-offset

Context

config>router>isis>link-group

Description

This command sets the offset value for the IPv6 multicast address family. If the number of operational links
drops below the oper-members threshold, the configured offset is applied to the interface metric for the IPv6
multicast topology.
The no form of the command reverts the offset value to 0.

Default
Parameters

no ipv6-multicast-metric-offset
offset-value — Specifies the amount the interface metric for the associated address family is to be increased
if the number of operational members in the associated link-group drops below the oper-members
threshold
Values

0 — 6777215

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default-metric
Syntaxdefault-metric ipv4 metricno default-metricContext

config>router>isis>level

Description
Default

This command specifies the configurable default metric used for all IS-IS interfaces on this level. This value
is not used if a metric is configured for an interface.
10
ipv4 metric — Specifies the default metric for IPv4 unicast.
Values

1 — 16777215

default-ipv4-multicast-metric
Syntaxdefault-ipv4-multicast-metric metricno default-ipv4-multicast-metricContext

config>router>isis>level

Description

This command configures the default metric to be used for the IS-IS interface in the IPv4 multicast topology(MT3).
The no form of this command deletes the specified default metric and reverts to using the system default of
10.

Default
Parameters10
metric — Specifies the default metric for interfaces in the IPv4 multicast topology (MT3)
Values

1 — 16777215

default-ipv6-multicast-metric
Syntaxdefault-ipv6-multicast-metric metricno default-ipv6-multicast-metricContext

config>router>isis>level

Description

This command configures the default metric to be used for the IS-IS interface in the IPv6 multicast topology(MT4).
The no form of this command deletes the specified default metric and reverts to using the system default of
10.

Default
Parameters

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10
metric — Specifies the default metric for interfaces in the IPv4 multicast topology (MT4).

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IS-IS1 — 16777215

default-ipv6-unicast-metric
Syntaxdefault-ipv6-unicast-metric ipv6 metricno default-ipv6-unicast-metricContext

config>router>isis>level

Description
Default
Parameters

This command specifies the default metric for IPv6 unicast.
no default-ipv6-unicast-metricipv6-metric — Specifies the default metric for IPv6 unicast.
Values

1 — 16777215

disable-ldp-sync
Syntax[no] disable-ldp-sync

Context

config>router>isis

Description

This command disables the IGP-LDP synchronization feature on all interfaces participating in the
OSPF or IS-IS routing protocol. When this command is executed, IGP immediately advertises theactual value of the link cost for all interfaces which have the IGP-LDP synchronization enabled if
the currently advertized cost is different. It will then disable IGP-LDP synchornization for all
interfaces. This command does not delete the interface configuration. The no form of thiscommand has to be entered to re-enable IGP-LDP synchronization for this routing protocol.
The no form of this command restores the default settings and re-enables IGP-LDP
synchronization on all interfaces participating in the OSPF or IS-IS routing protocol and for which
the ldp-sync-timer is configured.

Default

no disable-ldp-sync

exportSyntax[no] export policy-name [policy-name...up to 5 max]

Context

config>router>isis

Description

This command configures export routing policies that determine the routes exported from the routing table
to IS-IS.
If no export policy is defined, non IS-IS routes are not exported from the routing table manager to IS-IS.

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If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple export commands are issued, the last command entered overrides theprevious command. A maximum of five policy names can be specified.
If an aggregate command is also configured in the config>router context, then the aggregation is applied
before the export policy is applied.
Routing policies are created in the config>router>policy-options context.
The no form of the command removes the specified policy-name or all policies from the configuration if nopolicy-name is specified.
Default
Parameters

no export — No export policy name is specified.
policy-name — The export policy name. Up to five policy-name arguments can be specified.

export-limit
Syntaxexport-limit number [log percentage]
no export-limit

Context

config>router>isis
config>service>vprn>isis

Description

This command configures the maximum number of routes (prefixes) that can be exported into IS-IS from theroute table. After the maximum is reached, a warning log message is sent and additional routes are ignored.
The no form of the command removes the parameters from the configuration.

Default
Parameters

no export-limit, the export limit for routes or prefixes is disabled.
number — Specifies the maximum number of routes (prefixes) that can be exported into RIP from the routetable.
Values

1 — 4294967295

log percentage — Specifies the percentage of the export-limit, at which a warning log message and SNMP
notification would be sent.
Values

1 — 100

external-preference
Syntaxexternal-preference preference
no external-preferenceContext

config>router>isis>level level-number

Description

This command configures the external route preference for the IS-IS level.
The external-preference command configures the preference level of either IS-IS level 1 or IS-IS level 2
external routes. By default, the preferences are as listed in the table below.

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IS-ISA route can be learned by the router by different protocols, in which case, the costs are not comparable.
When this occurs, the preference decides the route to use.
Different protocols should not be configured with the same preference, if this occurs the tiebreaker is dependent on the default preference table. If multiple routes are learned with an identical preference using thesame protocol, the lowest cost route is used. If multiple routes are learned with an identical preference using
the same protocol and the costs (metrics) are equal, then the decision of the route to use is determined by theconfiguration of the ecmp in the config>router context.
Default

Default preferences are listed in the following table:

Route Type

Preference

Configurable

Direct attached

0No

Static-route5

Yes

OSPF internal routes

10

No

IS-IS Level 1 internal

15

Yes*

IS-IS Level 2 internal

18

Yes*

OSPF external

150

Yes

IS-IS Level 1 external

160

Yes

IS-IS Level 2 external

165

Yes

TMS

167

No

BGP

170

Yes

*. Internal preferences are changed using the preference command in the config>router>isis>level level-number
context

Parameters

preference — The preference for external routes at this level as expressed.
Values

1 — 255

graceful-restart
Syntax[no] graceful-restart

Context

config>router>isis
config>service>vprn>isis

Description

This command enables graceful-restart helper support for IS-IS. The router will act as a helper to neighbors
who are graceful-restart-capable and are restarting.
When the control plane of a graceful-restart-capable router fails, the neighboring routers (graceful-restarthelpers) temporarily preserve adjacency information so packets continue to be forwarded through the failed

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graceful-restart router using the last known routes. If the control plane of the graceful-restart router comesback up within the timer limits, then the routing protocols re-converge to minimize service interruption.
The no form of the command disables graceful restart and removes all graceful restart configurations in the
IS-IS instance.
Default

disabled

helper-disable
Syntax[no] helper-disable

Context

config>router>isis>graceful-restart
config>service>vprn>isis>graceful-restart

Description

This command disables the helper support for graceful restart.
When graceful-restart is enabled, the router can be a helper (meaning that the router is helping a neighborto restart) or be a restarting router or both. The router supports only helper mode. This facilitates the gracefulrestart of neighbors but will not act as a restarting router (meaning that the router will not help the neighbors
to restart).
The no helper-disable command enables helper support and is the default when graceful-restart is enabled.

Default

disabled

hello-authentication
Syntax[no] hello-authentication

Context

config>router>isis
config>router>isis>level level-number
config>service>vprn>isis
config>service>vprn>isis>interface
config>service>vprn>isis>level

Description

This command enables authentication of individual IS-IS packets of HELLO type.
The no form of the command suppresses authentication of HELLO packets.

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hello-padding
Syntax[no] hello-padding {adaptive | loose | strict}Context

config>router>isis
config>service>vprn>isis

Description

This command enables IS-IS Hello (IIH) message padding to ensure that IS-IS LSPs can traverse the link.
When this option is enabled, IS-IS Hello messages are padded to the maximum LSP MTU value, which canbe set with the "lsp-mtu-size" command.
The no form of the command disables IS-IS hello padding.

Default
Parameters

no hello-padding — hello padding is not configured
adaptive — Specifies the adaptive padding option; this option is able to detect LSP MTU asymmetry fromone side of the connection but uses more overhead than loose padding.
1. point-to-point interface—Hello PDUs are padded until the sender declares an adjacency on the link to
be in state up. If the implementation supports RFC 3373/5303, “Three-Way Handshake for IS-IS
Point-to- Point Adjacencies” then this is when the three-way state is Up. If the implementation use the“classic” algorithm described in ISO 10589, this is when adjacency state is Up. If the neighbor does
not support the adjacency state TLV, then padding continues.
2. broadcast interface—Padding starts until at least one adjacency is up on the interface.
loose — Specifies the loose padding option; the loose padding may not be able to detect certain situations
such as asymmetrical LSP MTUs between the routing devices.
1. point-to-point interface—The hello packet is padded from the initial detection of a new neighbor until
the adjacency transitions to the INIT state.
2. broadcast interface—Padding starts until there is at least one adjacency (broadcast only has up/down)
is up on the interface.
strict — Specifies the strict padding option; this option is the most overhead-intensive but detects LSP
MTU issues on both sides of a link.
1. point-to-point interface—Padding is done for all adjacency states, and is continuous.
2. broadcast interface—Padding is done for all adjacency states, and is continuous.

ignore-lsp-errors
Syntax[no] ignore-lsp-errors

Context

config>router>isis
config>service>vprn>isis

Description

This command specifies that IS-IS will ignore LSP packets with errors. When enabled, IS-IS LSP errors willbe ignored and the associated record will not be purged.
The no form of the command specifies that IS-IS will not ignore LSP errors.

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ignore-narrow-metric
Syntax[no] ignore-narrow-metricContext

config>router>isis

Description

This command specifies that IS-IS will ignore links with narrow metrics when wide-metrics support has
been enabled.
The no form of the command specifies that IS-IS will not ignore these links.

iid-tlv-enable
Syntax[no] iid-tlv-enable

Context

config>router>isis

Description

This command specifies whether Instance Identifier (IID) TLV has been enabled or disabled for this IS-IS
instance.
When enabled, each IS-IS instance marks its packets with the IID TLV containing its unique 16-bit IID forthe routing domain. You should shut/no shut the isis instance to make the change operational.

Default

no iid-tlv-enableinterface
Syntax[no] interface ip-int-nameContext

config>router>isis

Description

This command creates the context to configure an IS-IS interface.
When an area is defined, the interfaces belong to that area. Interfaces cannot belong to separate areas.
When the interface is a POS channel, the OSINCP is enabled when the interface is created and removed
when the interface is deleted.
The no form of the command removes IS-IS from the interface.
The shutdown command in the config>router>isis>interface context administratively disables IS-IS on theinterface without affecting the IS-IS configuration.

Default
Parameters

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no interface — No IS-IS interfaces are defined.
ip-int-name — Identify the IP interface name created in the config>router>interface context. The IP interface name must already exist.

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bfd-enable
Syntax[no] bfd-enable {ipv4 | ipv6} [include-bfd-tlv]

Context

config>router>isis>interface

Description

This command enables the use of bi-directional forwarding (BFD) to control IPv4 adjacencies. By enabling
BFD on an IPv4 or IPv6 protocol interface, the state of the protocol interface is tied to the state of the BFD
session between the local node and the remote node. The parameters used for the BFD are set by the BFD
command under the IP interface. This command must be given separately to enable/disable BFD for both
IPv4 and IPv6.
The no form of this command removes BFD from the associated adjacency.

Default
Parameters

no bfd-enable ipv4
include-bfd-tlv — Enables support for the IS-IS BFD TLV options, specified in RFC 6213, which specifies
that a BFD session must be established before an IS-IS adjacency can transition to the established state. This
option should be enabled on all IS-IS neighbors on a shared interface.

default-instance
Syntax[no] default-instanceContext

config>router>isis>interface ip-int-nameconfig>service>vprn>isis>interface ip-int-name

Description

This command enables a non-MI capable router to establish an adjacency and operate with an SR OS routerin a non-zero instance. If the router does not receive IID-TLVs, it will establish an adjacency in a single
instance. Instead of establishing an adjacency in the standard instance 0, the router will establish an adjacency in the configured non-zero instance. The router will then operate in the configured non-zero instanceso that it appears to be in the standard instance 0 to its neighbor. This feature is supported on point-to-pointinterfaces, broadcast interfaces are not supported.
The no form of this command disables the functionality so that the router can only establish adjacencies inthe standard instance 0.

Default

no default-instance

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hello-authentication-key
Syntax

hello-authentication-key [authentication-key | hash-key] [hash | hash2]
no hello-authentication-key

Context

config>router>isis>interface ip-int-nameconfig>router>isis>if>level level-number
config>service>vprn>isis>interface
config>service>vprn>isis>level

Description

This command configures the authentication key (password) for hello PDUs. Neighboring routers use thepassword to verify the authenticity of hello PDUs sent from this interface. Both the hello authentication key
and the hello authentication type on a segment must match. The hello-authentication-type must be specified.
To configure the hello authentication key in the interface context use the hello-authentication-key in theconfig>router>isis>interface context.
To configure or override the hello authentication key for a specific level, configure the hello-authentication-key in the config>router>isis>interface>level context.
If both IS-IS and hello-authentication are configured, hello messages are validated using hello authentication. If only IS-IS authentication is configured, it will be used to authenticate all IS-IS (including hello) protocol PDUs.
When the hello authentication key is configured in the config>router>isis>interface context, it applies toall levels configured for the interface.
The no form of the command removes the authentication-key from the configuration.

Default
Parameters

no hello-authentication-key — No hello authentication key is configured.
authentication-key — The hello authentication key (password). The key can be any combination of ASCII
characters up to 254 characters in length (un-encrypted). If spaces are used in the string, enclose theentire string in quotation marks (“ ”).
hash-key — The hash key. The key can be any combination of ASCII characters up to 342 characters inlength (encrypted). If spaces are used in the string, enclose the entire string in quotation marks (“ ”).
This is useful when a user must configure the parameter, but, for security purposes, the actual
unencrypted key value is not provided.
hash — Specifies the key is entered in an encrypted form. If the hash parameter is not used, the key isassumed to be in a non-encrypted, clear text form. For security, all keys are stored in encrypted form in
the configuration file with the hash parameter specified.
hash2 — Specifies the key is entered in a more complex encrypted form. If the hash2 parameter is not used,
the less encrypted hash form is assumed.

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hello-authentication-type
Syntax

hello-authentication-type {password | message-digest}
no hello-authentication-typeContext

config>router>isis>interface ip-int-nameconfig>router>isis>if>level level-number
config>service>vprn>isis>interface
config>service>vprn>isis>level

Description

This command enables hello authentication at either the interface or level context. Both the hello authentication key and the hello authentication type on a segment must match. The hello authentication-key statement
must also be included.
To configure the hello authentication type at the interface context, use hello-authentication-type in the config>router>isis>interface context.
To configure or override the hello authentication setting for a given level, configure the hello-authentication-type in the config>router>isis>interface>level context.
The no form of the command disables hello authentication.

Default
Parameters

no hello-authentication-type — Hello authentication is disabled.
password — Specifies simple password (plain text) authentication is required.
message-digest — Specifies MD5 authentication in accordance with RFC2104 (HMAC: Keyed-Hashingfor Message Authentication) is required.

hello-interval
Syntax

hello-interval seconds
no hello-interval

Context

config>router>isis>if>level level-number

Description

This command configures the interval in seconds between hello messages issued on this interface at thislevel.
The no form of the command to reverts to the default value.

Default

3 — Hello interval default for the designated intersystem.
9 — Hello interval default for non-designated intersystems.

Parameters

seconds — The hello interval in seconds expressed as a decimal integer.
Values

1 — 20000

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hello-multiplier
Syntax

hello-multiplier multiplier
no hello-multiplier

Context

config>router>isis>if>level level-number

Description

This command configures the number of missing hello PDUs from a neighbor after the router declares theadjacency down.
The no form of the command reverts to the default value.

Default
Parameters

3 — The router can miss up to 3 hello messages before declaring the adjacency down.
multiplier — The multiplier for the hello interval expressed as a decimal integer.
Values2 — 100

ipv6-unicast-metric
Syntaxipv6-unicast-metric metricno ipv6-unicast-metricContext

config>router>isis>if>level

Description

This command configures IS-IS interface metric for IPv6 unicast.
The no form of this command removes the metric from the configuration.

Parameters

metric — Specifies the IS-IS interface metric for IPv6 unicast.
Values

1 — 16777215

if-topology
Syntax

if-topology mt-id
no if-topology mt-id

Context

config>router>is-is>interface>level

Description

This command links the associated interface with the specified IS-IS topology.
By default all IS-IS interfaces should be associated the respective unicast topology. To exclude an interface
from the respective unicast topology use the command no if-topology <0|2>.
The no form of this command deletes the specified IS-IS topology.

Default
Parameters

No default
mt-id — Specify the topology to be created.
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interface-type
Syntaxinterface-type {broadcast | point-to-point}
no interface-typeContext

config>router>isis>interface ip-int-name

Description

This command configures the IS-IS interface type as either broadcast or point-to-point.
Use this command to set the interface type of an Ethernet link to point-to-point to avoid having to carry thedesignated IS-IS overhead if the link is used as a point-to-point.
If the interface type is not known at the time the interface is added to IS-IS and subsequently the IP interface
is bound (or moved) to a different interface type, then this command must be entered manually.
The no form of the command reverts to the default value.

Special Cases

SONET — Interfaces on SONET channels default to the point-to-point type.
Ethernet or Unknown — Physical interfaces that are Ethernet or unknown default to the broadcast type.

Default

point-to-point — For IP interfaces on SONET channels.
broadcast — For IP interfaces on Ethernet or unknown type physical interfaces.

Parameters

broadcast — Configures the interface to maintain this link as a broadcast network.
point-to-point — Configures the interface to maintain this link as a point-to-point link.

ipv4-node-sid
Syntaxipv4-node-sid index value
ipv4-node-sid label value
no ipv4-node-sid

Context

config>router>isis>interface

Description

This command assigns a node SID index or label value to the prefix representing the primary address ofan IPv4 network interface of type loopback. Only a single node SID can be assigned to an interface. The
secondary address of an IPv4 interface cannot be assigned a node SID index and does not inherit the
SID of the primary IPv4 address.
The above command should fail if the network interface is not of type loopback or if the interface isdefined in an IES or a VPRN context. Also, assigning the same SID index/label value to the same interface in two different IGP instances is not allowed within the same node.
The value of the label or index SID is taken from the range configured for this IGP instance. Whenusing the global mode of operation, a new segment routing module checks that the same index or label
value cannot be assigned to more than one loopback interface address. When using the per-instancemode of operation, this check is not required since the index and thus label ranges of the various IGP
instance are not allowed to overlap.

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Parametersindex value — integer.
Values

0 — 4294967295

Defaultnone

label value — integer.
Values

0 — 4294967295

Defaultnone

ipv4-multicast-routing
Syntaxipv4-multicast-routing {native | mt}[no] ipv4-multicast-routing

Context

config>router>isis

Description

The multicast RTM is used for Reverse Path Forwarding checks. This command controls which IS-IS topology is used to populate the IPv4 multicast RTM.
The no ipv4-multicast-routing form of the command results in none of the IS-IS routes being populated in
the IPv4 multicast RTM and would be used if multicast is configured to use the unicast RTM for the RPF
check.

Default
Parametersipv4-multicast-routing native
native — Causes IPv4 routes from the MT0 topology to be added to the multicast RTM for RPF checks.
mt — Causes IPv4 routes from the MT3 topology to be added to the multicast RTM for RPF checks.

ipv6-multicast-routing
Syntaxipv6-multicast-routing {native | mt}[no] ipv6-multicast-routing

Context

config>router>isis

Description

The multicast RTM is used for Reverse Path Forwarding checks. This command controls which IS-IS topology is used to populate the IPv6 multicast RTM.
The no ipv6-multicast-routing form of the command results in none of the IS-IS routes being populated in
the IPv4 multicast RTM and would be used if multicast is configured to use the unicast RTM for the RPF
check.

Default
Parametersipv6-multicast-routing native
native — Causes IPv6 routes from the MT0 topology to be added to the multicast RTM for RPF checks.
mt — Causes IPv6 routes from the MT3 topology to be added to the multicast RTM for RPF checks.

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ipv4-routing
Syntax[no] ipv4-routing

Context

config>router>isis

Description

This command specifies whether this IS-IS instance supports IPv4.
The no form of the command disables IPv4 on the IS-IS instance.

Default

ipv4-routing

ipv6-routing
Syntax[no] ipv6-routing {native | mt}

Context

config>router>isis

Description

This command enables IPv6 routing.
The no form of the command disables support for IS-IS IPv6 TLVs for IPv6 routing.

Default
Parameters

disabled
native — Enables IS-IS IPv6 TLVs for IPv6 routing and enables support for native IPv6 TLVs.
mt — Enables IS-IS multi-topology TLVs for IPv6 routing. When this parameter is specified, the support
for native IPv6 TLVs is disabled.

ldp-over-rsvp
Syntax[no] ldp-over-rsvp

Context

config>router>isis

Description

This command allows LDP over RSVP processing in IS-IS.
The no form of the command disables LDP over RSVP processing.

Default

no ldp-over-rsvp

level
Syntaxlevel {1 | 2}Context

config>router>isis
config>router>isis>interface ip-int-name

Description

This command creates the context to configure IS-IS Level 1 or Level 2 area attributes.

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A router can be configured as a Level 1, Level 2, or Level 1-2 system. A Level 1 adjacency can be established if there is at least one area address shared by this router and a neighbor. A Level 2 adjacency cannot beestablished over this interface.
Level 1/2 adjacency is created if the neighbor is also configured as Level 1/2 router and has at least one area
address in common. A Level 2 adjacency is established if there are no common area IDs.
A Level 2 adjacency is established if another router is configured as Level 2 or a Level 1/2 router with interfaces configured as Level 1/2 or Level 2. Level 1 adjacencies will not established over this interface.
To reset global and/or interface level parameters to the default, the following commands must be enteredindependently:
level> no hello-authentication-key
level> no hello-authentication-type
level> no hello-interval
level> no hello-multiplierlevel> no metriclevel> no passive
level> no priority
Special Cases

Global IS-IS Level — The config>router>isis context configures default global parameters for both
Level 1 and Level 2 interfaces.
IS-IS Interface Level — The config>router>isis>interface context configures IS-IS operational characteristics of the interface at Level 1 and/or Level 2. A logical interface can be configured on one Level 1 andone Level 2. In this case, each level can be configured independently and parameters must be removed independently.
By default an interface operates in both Level 1 and Level 2 modes.

Default
Parameterslevel 1 or level 2
1 — Specifies the IS-IS operational characteristics of the interface at level 1.
2 — Specifies the IS-IS operational characteristics of the interface at level 2.

level-capability
Syntaxlevel-capability {level-1 | level-2 | level-1/2}
no level-capability

Context

config>router>isis
config>router>isis>interface ip-int-name

Description

This command configures the routing level for an instance of the IS-IS routing process.
An IS-IS router and an IS-IS interface can operate at Level 1, Level 2 or both Level 1 and 2.

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Table 10 displays configuration combinations and the potential adjacencies that can be formed.
Table 10: Potential Adjacency
Global Level

Interface Level

Potential Adjacency

L 1/2

L 1/2

Level 1 and/or Level 2

L 1/2

L1

Level 1 only

L 1/2

L2

Level 2 only

L2

L 1/2

Level 2 only

L2

L2

Level 2 only

L2

L1

none

L1

L 1/2

Level 1 only

L1

L2

none

L1

L1

Level 1 only

The no form of the command removes the level capability from the configuration.
Special Cases

IS-IS Router — In the config>router>isis context, changing the level-capability performs a restart on the
IS-IS protocol instance.
IS-IS Interface — In the config>router>isis>interface context, changing the level-capability performs a
restart of IS-IS on the interface.

Default
Parameterslevel-1/2
level-1 — Specifies the router/interface can operate at Level 1only.
level-2 — Specifies the router/interface can operate at Level 2 only.
level-1/2 — Specifies the router/interface can operate at both Level 1 and Level 2.

loopfree-alternate
Syntaxloopfree-alternate [remote-lfa [max-pq-cost value]]
no loopfree-alternate

Context

config>router>isis

Description

This command enables Loop-Free Alternate (LFA) computation by SPF under the IS-IS routing protocol orunder the OSPF routing protocol instance.
When this command is enabled, it instructs the IGP SPF to attempt to pre-compute both a primary next-hop
and an LFA next-hop for every learned prefix. When found, the LFA next-hop is populated into the routing
table along with the primary next-hop for the prefix.

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The user enables the remote LFA next-hop calculation by the IGP LFA SPF by appending the remote-lfa
option. When this option is enabled in an IGP instance, SPF performs the remote LFA additional computation following the regular LFA next-hop calculation when the latter resulted in no protection for one or more
prefixes which are resolved to a given interface.
Remote LFA extends the protection coverage of LFA-FRR to any topology by automatically computing andestablishing/tearing-down shortcut tunnels, also referred to as repair tunnels, to a remote LFA node whichputs the packets back into the shortest without looping them back to the node which forwarded them over the
repair tunnel. The remote LFA node is referred to as PQ node. A repair tunnel can in theory be an RSVP
LSP, a LDP-in-LDP tunnel, or a SR tunnel. In this feature, it is restricted to use SR repair tunnel to theremote LFA node.
The remote LFA algorithm is a per-link LFA SPF calculation and not a per-prefix like the regular LFA one.
So, it provides protection for all destination prefixes which share the protected link by using the neighbor on
the other side of the protected link as a proxy for all these destinations.
The no form of this command disables the LFA computation by IGP SPF.
Default
Parameters

no loopfree-alternate
max-pq-cost value — integer used to limit the search of candidate P and Q nodes in remote LFA by setting
the maximum IGP cost from the router performing remote LFA calculation to the candidate P or Q node.
Values

0 – 4294967295

Defaultnone

loopfree-alternate-exclude
Syntaxloopfree-alternate-exclude prefix-policy prefix-policy [prefix-policy... up to 5]
no loopfree-alternate-exclude

Context

config>router>isis
config>service>vprn>isis

Description

This command excludes from LFA SPF calculation prefixes that match a prefix entry or a tag entry in aprefix policy.
The implementation already allows the user to exclude an interface in IS-IS or OSPF, an OSPF area, or an
IS-IS level from the LFA SPF.
If a prefix is excluded from LFA, then it will not be included in LFA calculation regardless of its priority. The
prefix tag will, however, be used in the main SPF. Note that prefix tags are defined for the IS-IS protocol but
not for the OSPF protocol.
The default action of the loopfree-alternate-exclude command, when not explicitly specified by the user inthe prefix policy, is a “reject”. Thus, regardless if the user did or did not explicitly add the statement“default-action reject” to the prefix policy, a prefix that did not match any entry in the policy will be accepted
into LFA SPF.
The no form deletes the exclude prefix policy.

Parameters

prefix-policy prefix-policy — Specifies the name of the prefix policy, up to 32 characters. The specified
name must have been already defined.

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lfa-policy-map
Syntaxlfa-policy-map route-nh-template template-nameno lfa-policy-map

Context

config>router>isis>interface

Description

This command applies a route next-hop policy template to an OSPF or IS-IS interface.
When a route next-hop policy template is applied to an interface in IS-IS, it is applied in both level 1 andlevel 2. When a route next-hop policy template is applied to an interface in OSPF, it is applied in all areas.
However, the command in an OSPF interface context can only be executed under the area in which thespecified interface is primary and then applied in that area and in all other areas where the interface issecondary. If the user attempts to apply it to an area where the interface is secondary, the command will fail.
If the user excluded the interface from LFA using the command loopfree-alternate-exclude, the LFA
policy, if applied to the interface, has no effect.
Finally, if the user applied a route next-hop policy template to a loopback interface or to the system interface,
the command will not be rejected, but it will result in no action being taken.
The no form deletes the mapping of a route next-hop policy template to an OSPF or IS-IS interface.

Parameters

template-name — Specifies the name of the template, up to 32 characters.

loopfree-alternate-exclude
Syntax[no] loopfree-alternate

Context

configure>router>isis>level
configure>router>isis>interface
configure>service>vprn>isis>level
configure>service>vprn>isis>interface

Description

This command instructs IGP to not include a specific interface or all interfaces participating in a specific ISIS level or OSPF area in the SPF LFA computation. This provides a way of reducing the LFA SPF calculation where it is not needed.
When an interface is excluded from the LFA SPF in IS-IS, it is excluded in both level 1 and level 2. When it
is excluded from the LFA SPF in OSPF, it is excluded in all areas. However, the above OSPF command can
only be executed under the area in which the specified interface is primary and once enabled, the interface is
excluded in that area and in all other areas where the interface is secondary. If the user attempts to apply it toan area where the interface is secondary, the command will fail.
The no form of this command re-instates the default value for this command.

Default

no loopfree-alternate-exclude

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lsp-pacing-interval
Syntaxlsp-pacing-interval milliseconds
no lsp-pacing-interval

Context

config>router>isis>interface

Description

This command configures the interval between LSP PDUs sent from this interface.
To avoid bombarding adjacent neighbors with excessive data, pace the Link State Protocol Data Units(LSPs). If a value of zero is configured, no LSPs are sent from the interface.
The no form of the command reverts to the default value.

Default
Parameters

100 — LSPs are sent in 100 millisecond intervals.
milliseconds — The interval in milliseconds that IS-IS LSPs can be sent from the interface expressed as adecimal integer.
Values

0 — 65535

lsp-lifetime
Syntaxlsp-lifetime seconds
no lsp-lifetime

Context

config>router>isis

Description

This command sets the time, in seconds, the router wants the LSPs it originates to be considered valid byother routers in the domain.
Each LSP received is maintained in an LSP database until the lsp-lifetime expires unless the originatingrouter refreshes the LSP. By default, each router refreshes its LSPs every 20 minutes (1200 seconds) so otherrouters will not age out the LSP.
The LSP refresh timer is derived from this formula: lsp-lifetime/2
The no form of the command reverts to the default value.

Default
Parameters

1200 — LSPs originated by the router should be valid for 1200 seconds (20 minutes).
seconds — The time, in seconds, that the router wants the LSPs it originates to be considered valid by otherrouters in the domain.
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lsp-mtu-size
Syntaxlsp-mtu-size size
no lsp-mtu-size

Context

config>router>isis

Description

This command configures the LSP MTU size. If the size value is changed from the default using CLI or
SNMP, then IS-IS must be restarted in order for the change to take effect. This can be done by performing a
shutdown command and then a no shutdown command in the config>router>isis context. Note: Using theexec command to execute a configuration file to change the LSP MTU-size from its default value will automatically bounce IS-IS for the change to take effect.
The no form of the command reverts to the default value.

Default
Parameters

1492
size — Specifies the LSP MTU size.
Values490 — 9190

lsp-refresh-interval
Syntaxlsp-refresh-interval seconds
no lsp-refresh-interval

Context

config>router>isis

Description

This command configures the IS-IS LSP refresh timer interval. When configuring the LSP refresh interval,
the value that is specified for lsp-lifetime must also be considered. The LSP refresh interval cannot begreater than 90% of the LSP lifetime.
The no form of the command reverts to the default (600 seconds), unless this value is greater than 90% of the
LSP lifetime. For example, if the LSP lifetime is 400, then the no lsp-refresh-interval command will berejected.

Default
Parameters

600 seconds
seconds — Specifies the refresh interval.
Values150— 65535

lsp-wait
Syntaxlsp-wait lsp-wait [lsp-initial-wait [lsp-second-wait]]

Context

config>router>isis

Description

This command is used to customize the throttling of IS-IS LSP-generation. Timers that determine when to
generate the first, second and subsequent LSPs can be controlled with this command. Subsequent LSPs are
generated at increasing intervals of the second lsp-wait timer until a maximum value is reached.

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Parameterslsp-max-wait — Specifies the maximum interval in seconds between two consecutive ocurrences of an LSP
being generated.
Values

1 — 120

Default

5

lsp-initial-wait — Specifies the initial LSP generation delay in seconds.
Values

0 — 100

Default

0

lsp-second-wait — Specifies the hold time in seconds between the first and second LSP generation.
Values

1 — 100

Default1

ipv4-multicast
Syntax[no] ipv4-multicast

Context

config>router>is-is>multi-topology

Description

This command enables support for the IPv4 topology (MT3) within the associate IS-IS instance.
The no form of this command disables support for the IPv4 topology (MT3) within the associated IS-IS
instance.

Default

no ipv4-multicast

ipv6-multicast
Syntax[no] ipv6-multicast

Context

config>router>is-is>multi-topology

Description

This command enables support for the IPv6 topology (MT4) within the associate IS-IS instance.
The no form of this command disables support for the IPv6 topology (MT4) within the associated IS-IS
instance.

Default

no ipv6-multicast

mcast-import-ipv6
Syntax[no] mcast-import-ipv6

Context

configure>router>isis

Description

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This command administratively enables/disables submission of routes into the IPv6 multicast RTM by IS-IS.

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multi-topology
Syntax[no] multi-topology

Context

config>router>isis

Description
Default

This command enables IS-IS multi-topology support.
disabled

topology
Syntax

topology mt-id rtm rtm-id | rtm-nameno topology mt-id

Context

config>router>is-is>multi-topology

Description

This command creates a new topology within the associate IS-IS instance. In addition, it associates the IS-IS
topology with the specified RTM instance. Routes generated from the topology SPF calculation are in turnadded to this associate RTM instance.
The no form of this command deletes the specified IS-IS topology.

Default
Parameters

No default
mt-id — Specify the topology to be created (Note: in Release 11.0 this parameters is limited to 3 or 4.
rtm-id — RTM Instance ID that is to be associated with the new IS-IS topology.
Valuesinteger: 3 — 32

rtm-name — string name given to the RTM instance.

ipv6-unicast
Syntax[no] ipv6-unicast

Context

config>router>isis>multi-topology

Description

This command enables multi-topology TLVs.
The no form of the command disables multi-topology TLVs.

multicast-import
Syntax[no] multicast-import

Context

config>router>isis

Description

This command enables the submission of routes into the multicast Route Table Manager (RTM) by IS-IS.

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The no form of the command disables the submission of routes into the multicast RTM.
Default

no multicast-importmesh-group
Syntaxmesh-group {value | blocked}
no mesh-groupContext

config>router>isis>interface ip-int-name

Description

This command assigns an interface to a mesh group. Mesh groups limit the amount of flooding that occurs
when a new or changed LSP is advertised throughout an area.
All routers in a mesh group should be fully meshed. When LSPs need to be flooded, only a single copy isreceived rather than a copy per neighbor.
To create a mesh group, configure the same mesh group value for each interface that is part of the meshgroup. All routers must have the same mesh group value configured for all interfaces that are part of themesh group.
To prevent an interface from flooding LSPs, the optional blocked parameter can be specified. Configure
mesh groups carefully. It is easy to created isolated islands that do not receive updates as (other) links fail.
The no form of the command removes the interface from the mesh group.

Default
Parameters

no mesh-group — The interface does not belong to a mesh group.
value — The unique decimal integer value distinguishes this mesh group from other mesh groups on this or
any other router that is part of this mesh group.
Values

1 — 2000000000

blocked — Prevents an interface from flooding LSPs.

ipv6-unicast-disable
Syntax[no] ipv6-unicast-disable

Context

config>router>isis>if

Description

This command disables IS-IS IPv6 unicast routing for the interface.
By default IPv6 unicast on all interfaces is enabled. However, IPv6 unicast routing on IS-IS is in effect when
the config>router>isis>ipv6-routing mt command is configured.
The no form of the command enables IS-IS IPv6 unicast routing for the interface.

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metric
Syntaxmetric metricno metricContext

config>router>isis>if>level level-number

Description

This command configures the metric used for the level on the interface.
In order to calculate the lowest cost to reach a given destination, each configured level on each interface
must have a cost. The costs for each level on an interface may be different.
If the metric is not configured, the default of 10 is used unless reference bandwidth is configured.
The no form of the command reverts to the default value.

Default
Parameters

10 — A metric of 10 for the level on the interface is used.
metric — The metric assigned for this level on this interface.
Values

1 — 16777215

advertise-passive-only
Syntax[no] advertise-passive-onlyContext

config>router>isis

Description

This command enables and disables IS-IS to advertise only prefixes that belong to passive interfaces.

advertise-router-capability
Syntaxadvertise-router-capability {area | as}
no advertise-router-capability

Context

config>router>isis

Description

This command enables advertisement of a router's capabilities to its neighbors for informational andtroubleshooting purposes. A TLV as defined in RFC 4971 advertises the TE Node Capability Descriptor
capability.
The parameters (area and as) control the scope of the capability advertisements.
The no form of this command, disables this capability.

Default
Parameters

no advertise-router-capability
area — are only advertised within the area of origin.
as — are only advertised throughout the entire autonomous system

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area-id
Syntax[no] area-id area-address

Context

config>router>isis

Description

This command was previously named the net network-entity-title command. The area-id command allows
you to configure the area ID portion of NSAP addresses which identifies a point of connection to the network, such as a router interface, and is called a Network Service Access Point (NSAP). Addresses in the ISIS protocol are based on the ISO NSAP addresses and Network Entity Titles (NETs), not IP addresses.
A maximum of 3 area addresses can be configured.
NSAP addresses are divided into three parts. Only the area ID portion is configurable.
• Area ID — A variable length field between 1 and 13 bytes long. This includes the Authority and Format
Identifier (AFI) as the most significant byte and the area ID.
• System ID — A six-byte system identification. This value is not configurable. The system ID is derived
from the system or router ID.
• Selector ID — A one-byte selector identification that must contain zeros when configuring a NET. Thisvalue is not configurable. The selector ID is always 00.
The NET is constructed like an NSAP but the selector byte contains a 00 value. NET addresses areexchanged in hello and LSP PDUs. All net addresses configured on the node are advertised to its neighbors.
For Level 1 interfaces, neighbors can have different area IDs, but, they must have at least one area ID (AFI +area) in common. Sharing a common area ID, they become neighbors and area merging between the potentially different areas can occur.
For Level 2 (only) interfaces, neighbors can have different area IDs. However, if they have no area IDs incommon, they become only Level 2 neighbors and Level 2 LSPs are exchanged.
For Level 1 and Level 2 interfaces, neighbors can have different area IDs. If they have at least one area ID(AFI + area) in common, they become neighbors. In addition to exchanging Level 2 LSPs, area merging
between potentially different areas can occur.
If multiple area-id commands are entered, the system ID of all subsequent entries must match the first area
address.
The no form of the command removes the area address.

Default
Parameters

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none — No area address is assigned.
area-address — The 1 — 13-byte address. Of the total 20 bytes comprising the NET, only the first 13 bytes
can be manually configured. As few as one byte can be entered or, at most, 13 bytes. If less than 13 bytes areentered, the rest is padded with zeros.

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overload
Syntaxoverload [timeout seconds]
no overload

Context

config>router>isis

Description

This command administratively sets the IS-IS router to operate in the overload state for a specific time
period, in seconds, or indefinitely.
During normal operation, the router may be forced to enter an overload state due to a lack of resources.
When in the overload state, the router is only used if the destination is reachable by the router and will not
used for other transit traffic.
If a time period is specified, the overload state persists for the configured length of time. If no time is specified, the overload state operation is maintained indefinitely.
The overload command is cleared from the configuration after a reboot if overload-on-boot is configured
with or without a timeout value. To keep the IS-IS router in the overload state indefinitely after rebooting,configure overload-on-boot with no timeout value or configure the overload command with no overload-onboot command.
The overload command can be useful in circumstances where the router is overloaded or used prior to executing a shutdown command to divert traffic around the router.
The no form of the command causes the router to exit the overload state.

Default
Parameters

no overload
seconds — The time, in seconds, that this router must operate in overload state.
Default

infinity (overload state maintained indefinitely)

Values60 — 1800

overload-on-bootSyntaxoverload-on-boot [timeout seconds]
no overload-on-bootContext

config>router>isis

Description

When the router is in an overload state, the router is used only if there is no other router to reach thedestination. This command configures the IGP upon bootup in the overload state until one of the following
events occur:
1. The timeout timer expires.
2. A manual override of the current overload state is entered with the config>router>isis>no overload
command.
The no overload command does not affect the overload-on-boot function.
If no timeout is specified, IS-IS will go into overload indefinitely after a reboot. After the reboot, the IS-IS
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L1 LSDB Overload : Manual on boot (Indefinitely in overload)
L2 LSDB Overload : Manual on boot (Indefinitely in overload)
This state can be cleared with the config>router>isis>no overload command.
When specifying a timeout value, IS-IS will go into overload for the configured timeout after a reboot. Afterthe reboot, the IS-IS status will display the remaining time the system stays in overload:
L1 LSDB Overload : Manual on boot (Overload Time Left : 17)
L2 LSDB Overload : Manual on boot (Overload Time Left : 17)
The overload state can be cleared before the timeout expires with the config>router>isis>no overload command.
The no form of the command removes the overload-on-boot functionality from the configuration.
Default

no overload-on-bootUse the show router isis status command to display the administrative and operational state as well as all
timers.

Parameters

timeout seconds — Configure the timeout timer for overload-on-boot in seconds.
Values60 — 1800

poi-tlv-enable
Syntaxpoi-tlv-enable
no poi-tlv-enable

Context

config>router>isis

Description

Enable use of Purge Originator Identification (POI) TLV for this IS-IS instance. The POI is added to purges
and contains the system ID of the router that generated the purge, which simplifies troubleshooting anddetermining what caused the purge.
The no form of the command removes the POI functionality from the configuration.

Default

no poi-tlv-enablepassive
Syntax[no] passive

Context

config>router>isis>if
config>router>isis>if>level

Description

This command adds the passive attribute which causes the interface to be advertised as an IS-IS interface
without running the IS-IS protocol. Normally, only interface addresses that are configured for IS-IS are
advertised as IS-IS interfaces at the level that they are configured.
When the passive mode is enabled, the interface or the interface at the level ignores ingress IS-IS protocol
PDUs and will not transmit IS-IS protocol PDUs.

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The no form of the command removes the passive attribute.
Special Cases

Service Interfaces — Service interfaces (defined using the service-prefix command in config>router)are passive by default.
All other Interfaces — All other interfaces are not passive by default.

Default

passive — Service interfaces are passive.
no passive — All other interfaces are not passive.

preference
Syntaxpreference preference
no preferenceContext

config>router>isis>level

Description

This command configures the preference level of either IS-IS Level 1 or IS-IS Level 2 internal routes. By
default, the preferences are listed in the table below.
A route can be learned by the router by different protocols, in which case, the costs are not comparable.
When this occurs, the preference is used to decide to which route will be used.
Different protocols should not be configured with the same preference, if this occurs the tiebreaker is per thedefault preference table as defined in the following table. If multiple routes are learned with an identicalpreference using the same protocol, the lowest cost route is used. If multiple routes are learned with an identical preference using the same protocol and the costs (metrics) are equal, then the decision what route to use
is determined by the configuration of the ecmp in the config>router context.

Default

Default preferences are listed in the following table:
Route Type

Preference

Configurable

Direct attached

0No

Static-route5

Yes

OSPF internal routes

10

No

IS-IS level 1 internal

15

Yes

IS-IS level 2 internal

18

Yes

OSPF external

150

Yes

IS-IS level 1 external

160

Yes*

IS-IS level 2 external

165

Yes*

BGP

170

Yes

*. External preferences are changed using the external-preference command in the config>router>isis>level
level-number context.

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Parameters

preference — The preference for external routes at this level expressed as a decimal integer.
Values

1 — 255

priority
Syntaxpriority number
no priority

Context

config>router>isis>if>level level-number

Description

This command configures the priority of the IS-IS router interface for designated router election on a multiaccess network.
This priority is included in hello PDUs transmitted by the interface on a multi-access network. The routerwith the highest priority is the preferred designated router. The designated router is responsible for sending
LSPs with regard to this network and the routers that are attached to it.
The no form of the command reverts to the default value.

Default
Parameters64
number — The priority for this interface at this level.
Values

0 — 127

sd-offset
Syntaxsd-offset offset-value
no sd-offset

Context

config>router>isis>if>level

Description

If the pre-FEC error rate of the associated DWDM port crosses the configured sd-threshold, this offsetvalue is added to the IS-IS interface metric. This parameter is only effective if the interface is associated witha DWDM port and the sd-threshold value is configured under that port.
The no form of the command reverts the offset value to 0.

Default
Parameters

no sd-offset
offset-value — Specifies the amount the interface metric is increased by if the sd-threshold is crossed.
ValuesPage 570

0 — 16777215

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sf-offset
Syntaxsf-offset offset-value
no sf-offset

Context

config>router>isis>if>level

Description

If the pre-FEC error rate of the associated DWDM port crosses the configured sf-threshold, this offset-value
is added to the IS-IS interface metric. This parameter is only effective if the interface is associated with a
DWDM port and the sf-threshold value is configured under that port.
The no form of the command reverts the offset value to 0.

Default
Parameters

no sf-offset
offset-value — Specifies the amount the interface metric is increased by if the sf-threshold is crossed.
Values

0 — 16777215

psnp-authentication
Syntax[no] psnp-authentication

Context

config>router>isis
config>router>isis>level

Description

This command enables authentication of individual IS-IS packets of partial sequence number PDU (PSNP)
type.
The no form of the command suppresses authentication of PSNP packets.

reference-bandwidth
Syntaxreference-bandwidth bandwidth-in-kbps
reference-bandwidth [tbps Tera-bps] [gbps Giga-bps] [mbps Mega-bps] [kbps Kilo-bps]
no reference-bandwidth

Context

config>router>isis

Description

This command configures the reference bandwidth that provides the basis of bandwidth relative costing.
In order to calculate the lowest cost to reach a specific destination, each configured level on each interface
must have a cost. If the reference bandwidth is defined, then the cost is calculated using the following formula:cost = reference-bandwidth ÷ bandwidth7950 XRS Routing Protocols Guide

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If the reference bandwidth is configured as 10 Gigabits (10,000,000,000), a 100 M/bps interface has a default
metric of 100. In order for metrics in excess of 63 to be configured, wide metrics must be deployed. (Seewide-metrics-only in the config>router>isis context.)
If the reference bandwidth is not configured, then all interfaces have a default metric of 10.
The no form of the command reverts to the default value.
Default

no reference-bandwidth — No reference bandwidth is defined. All interfaces have a metric of 10.

Parameters

bandwidth-in-kbps — The reference bandwidth in kilobits per second expressed as a decimal integer.
Values

1 — 1000000000

tbps Tera-bps — The reference bandwidth in terabits per second expressed as a decimal integer.
Values1—4gbps Giga-bps — The reference bandwidth in gigabits per second expressed as a decimal integer.
Values

1 — 999mbps Mega-bps — The reference bandwidth in megabits per second expressed as a decimal integer.
Values

1 — 999kbps Kilo-bps — reference bandwidth in kilobits per second expressed as a decimal integer.
Values

1 — 999

rib-priority
Syntaxrib-priority {high} prefix-list-name | tag tag-value
no rib-priority

Context

config>router>isis

Description

This command enabled RIB prioritization for the IS-IS protocol and specifies the prefix list or IS-IS tagvalue that will be used to select the specific routes that should be processed through the IS-IS route calculation process at a higher priority.
The no rib-priority form of command disables RIB prioritization.

Default
Parameters

no rib-priority
prefix-list-name — specifies the prefix list which is used to select the routes that are processed at a higher
priority through the route calculation process.
tag tag-value — specifies the tag value that is used to match IS-IS routes that are to be processed at a higher
priority through the route calculation process.
ValuesPage 572

1 – 4294967295

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rsvp-shortcut
Syntax[no] rsvp-shortcut

Context

config>router>isis

Description

This command enables the use of an RSVP-TE shortcut for resolving IGP routes by IS-IS or OSPF routing
protocols.
This command instructs IS-IS or OSPF to include RSVP LSPs originating on this node and terminating on
the router-id of a remote node as direct links with a metric equal to the operational metric provided by
MPLS. Note that Dijkstra will always use the IGP metric to build the SPF tree and the LSP metric value does
not update the SPF tree calculation. During the IP reach to determine the reachability of nodes and prefixes,
LSPs are then overlaid and the LSP metric is used to determine the subset of paths which are equal lowest
cost to reach a node or a prefix. If the user enabled the relative-metric option for this LSP, IGP will apply
the shortest IGP cost between the endpoints of the LSP plus the value of the offset, instead of the LSP operational metric, when computing the cost of a prefix which is resolved to the LSP.
When a prefix is resolved to a tunnel next-hop, the packet is sent labeled with the label stack corresponding
to the NHLFE of the RSVP LSP. Any network event causing an RSVP LSP to go down will trigger a full
SPF computation which may result in installing a new route over another RSVP LSP shortcut as tunnel nexthop or over a regular IP next-hop.
When rsvp-shortcut is enabled at the IGP instance level, all RSVP LSPs originating on this node are eligible
by default as long as the destination address of the LSP, as configured in configure>router>mpls>lsp>to,corresponds to a router-id of a remote node. RSVP LSPs with a destination corresponding to an interface
address or any other loopback interface address of a remote node are automatically not considered by IS-IS
or OSPF. The user can, however, exclude a specific RSVP LSP from being used as a shortcut for resolving
IGP routes by entering the config>router>mpls>lsp>no igp-shortcut command.
The SPF in OSPF or IS-IS will only use RSVP LSPs as forwarding adjacencies, IGP shortcuts, or as endpoints for LDP-over-RSVP. These applications of RSVP LSPs are mutually exclusive at the IGP instancelevel. If the user enabled two or more options in the same IGP instance, then forwarding adjacency takes
precedence over the shortcut application, which takes precedence over the LDP-over-RSVP application.
When ECMP is enabled on the system and multiple equal-cost paths exist for a prefix, the following selection criteria are used to pick up the set of next-hops to program in the data path:• for a destination = tunnel-endpoint (including external prefixes with tunnel-endpoint as the next-hop):→ select tunnel with lowest tunnel-index (ip next-hop is never used in this case)• for a destination != tunnel-endpoint:→ exclude LSPs with metric higher than underlying IGP cost between the endpoint of the LSP→ prefer tunnel next-hop over ip next-hop→ within tunnel next-hops:
i. select lowest endpoint to destination costii. if same endpoint to destination cost, select lowest endpoint node router-id
iii. if same router-id, select lowest tunnel-index→ within ip next-hops:
i. select lowest downstream router-id
ii. if same downstream router-id, select lowest interface-index

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IS-IS Commands• Note though no ECMP is performed across both the IP and tunnel next-hops the tunnel endpoint lies in
one of the shortest IGP paths for that prefix. In that case, the tunnel next-hop is always selected as longas the prefix cost using the tunnel is equal or lower than the IGP cost.
The ingress IOM will spray the packets for this prefix over the set of tunnel next-hops and IP next-hops
based on the hashing routine currently supported for IPv4 packets.
This feature provides IGP with the capability to populate the multicast RTM with the prefix IP next-hop
when both the rsvp-shortcut and the multicast-import options are enabled in IGP. The unicast RTM canstill make use of the tunnel next-hop for the same prefix. This change is made possible with the enhancement
by which SPF keeps track of both the direct first hop and the tunneled first hop of a node which is added to
the Dijkstra tree.
The resolution and forwarding of IPv6 prefixes to IPv4 IGP shortcuts is not supported.
The no form of this command disables the resolution of IGP routes using RSVP shortcuts.
Default

no rsvp-shortcut

segment-routing
Syntaxsegment-routing
no segment-routing

Context

config>router>isis

Description

This command enables the context to configure segment routing parameters within a given IGP instance.
Segment routing adds to IS-IS and OSPF routing protocols the ability to perform shortest path routing andsource routing using the concept of abstract segment. A segment can represent a local prefix of a node, a specific adjacency of the node (interface/next-hop), a service context, or a specific explicit path over the network. For each segment, the IGP advertises an identifier referred to as Segment ID (SID).
When segment routing is used together with MPLS data plane, the SID is a standard MPLS label. A routerforwarding a packet using segment routing will thus push one or more MPLS labels.
Segment routing using MPLS labels can be used in both shortest path routing applications and in traffic engineering applications. This feature implements the shortest path forwarding application.
After segment routing is successfully enabled in the IS-IS or OSPF instance, the router will perform the following operations:
1. Advertize the Segment Routing Capability Sub-TLV to routers in all areas/levels of this IGP instance.
However, only neighbors with which it established an adjacency will interpret the SID/label range
information and use it for calculating the label to swap to or push for a given resolved prefix SID.
2. Advertise the assigned index for each configured node SID in the new prefix SID sub-TLV with the Nflag (node-SID flag) set. Then the segment routing module programs the incoming label map (ILM)with a pop operation for each local node SID in the data path.
3. Assign and advertize automatically an adjacency SID label for each formed adjacency over a network
IP interface in the new Adjacency SID sub-TLV. The segment routing module programs the incominglabel map (ILM) with a pop operation, in effect with a swap to an implicit null label operation, for eachadvertised adjacency SID.

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4. Resolve received prefixes and if a prefix SID sub-TLV exists, the Segment Routing module programs
the ILM with a swap operation and also an LTN with a push operation both pointing to the primary/
LFA NHLFE. An SR tunnel is also added to the TTM.
When the user enables segment routing in a given IGP instance, the main SPF and LFA SPF are computed
normally and the primary next-hop and LFA backup next-hop for a received prefix are added to RTM without the label information advertised in the prefix SID sub-TLV.

prefix-sid-range
Syntaxprefix-sid-range {global | start-label label-value max-index index-value}
no prefix-sid-range

Context

config>router>isis>segment-routing

Description

This command configures the prefix SID index range and offset label value for a given IGP instance.
The key parameter is the configuration of the prefix SID index range and the offset label value which this
IGP instance will use. Since each prefix SID represents a network global IP address, the SID index for a prefix must be network-wide unique. Thus, all routers in the network are expected to configure and advertisethe same prefix SID index range for a given IGP instance. However, the label value used by each router torepresent this prefix; that is, the label programmed in the ILM can be local to that router by the use of an offset label, referred to as a start label:
Local Label (Prefix SID) = start-label + {SID index}
The label operation in the network becomes thus very similar to LDP when operating in the independentlabel distribution mode (RFC 5036) with the difference that the label value used to forward a packet to eachdownstream router is computed by the upstream router based on advertised prefix SID index using the above
formula.
There are two mutually exclusive modes of operation for the prefix SID range on the router. In the global
mode of operation, the user configures the global value and this IGP instance will assume the start label
value is the lowest label value in the SRGB and the prefix SID index range size equal to the range size of theSRGB. Once one IGP instance selected the global option for the prefix SID range, all IGP instances on thesystem will be restricted to do the same. The user must shutdown the segment routing context and delete theprefix-sid-range command in all IGP instances in order to change the SRGB. Once the SRGB is changed,
the user must re-enter the prefix-sid-range command again. The SRGB range change will be failed if analready allocated SID index/label goes out of range.
In the per-instance mode of operation, the user partitions the SRGB into non-overlapping sub-ranges among
the IGP instances. The user thus configures a subset of the SRGB by specifying the start label value and theprefix SID index range size. Note that all resulting net label values (start-label + index} must be within the
SRGB or the configuration will be failed. Furthermore, the code checks for overlaps of the resulting net
label value range across IGP instances and will strictly enforce that these ranges do not overlap. The user
must shutdown the segment routing context of an IGP instance in order to change the SID index/label rangeof that IGP instance using the prefix-sid-range command. In addition, any range change will be failed if analready allocated SID index/label goes out of range. The user can however change the SRGB on the fly as
long as it does not reduce the current per IGP instance SID index/label range defined with the prefix-sidrange. Otherwise, the user must shutdown the segment routing context of the IGP instance and delete andre-configure the prefix-sid-range command.

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Parameters

start-label label-value — the label offset for the SR label range of this IGP instance.
Values

0 — 524287

Defaultnone

max-index index-value — the maximum value of the prefix SID index range for this IGP instance.
Values

1 — 524287

Defaultnone

tunnel-mtu
Syntaxtunnel-mtu bytes
no tunnel-mtu

Context

config>router>isis>segment-routing

Description

This command configures configure the MTU of all SR tunnels within each IGP instance.
The MTU of a SR tunnel populated into TTM is determined like in the case of an IGP tunnel; for example,
LDP LSP, based on the outgoing interface MTU minus the label stack size. Remote and directed LFA can
add at least two more labels to the tunnel for a total of three. There is no default value for this new command.
If the user does not configure a SR tunnel MTU, the MTU will be fully determined by IGP as explained
below.
The MTU of the SR tunnel is then determined as follows:
SR_Tunnel_MTU = MIN {Cfg_SR_MTU, IGP_Tunnel_MTU- 3 labels}
Where,
Cfg_SR_MTU is the MTU configured by the user for all SR tunnels within a given IGP instance using theabove CLI. If no value was configured by the user, the SR tunnel MTU will be fully determined by the IGP
interface calculation explained next.
IGP_Tunnel_MTU is the minimum of the IS-IS or OSPF interface MTU among all the ECMP paths oramong the primary and LFA backup paths of this SR tunnel.
The SR tunnel MTU is dynamically updated anytime any of the above parameters used in its calculation
changes. This includes when the set of the tunnel next-hops changes or the user changes the configured SR
MTU or interface MTU value.

Parameters

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bytes — the size of the Maximum Transmission Unit (MTU) in bytes.
Values512— 9198

Default

none

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IS-IStunnel-table-pref
Syntaxtunnel-table-pref preference
no tunnel-table-prefContext

config>router>isis>segment-routing

Description

This command configures the TTM preference of SR tunnels created by the IGP instance. This is used in thecase of BGP shortcuts, VPRN auto-bind, or BGP transport tunnel when the new tunnel binding commands
are configured to the any value which parses the TTM for tunnels in the protocol preference order. The user
can choose to either go with the global TTM preference or list explicitly the tunnel types they want to use.
When they list the tunnel types explicitly, the TTM preference will still be used to select one type over theother. In both cases, a fallback to the next preferred tunnel type is performed if the selected one fails. Also, areversion to a more preferred tunnel type is performed as soon as one is available.
The segment routing module adds to TTM a SR tunnel entry for each resolved remote node SID prefix andprograms the data path with the corresponding LTN with the push operation pointing to the primary and LFA
backup NHLFEs .
The default preference for SR tunnels in the TTM is set lower than LDP tunnels but higher than BGP tunnels
to allow controlled migration of customers without disrupting their current deployment when they enable
segment routing. The following is the setting of the default preference of the various tunnel types. This
includes the preference of SR tunnels based on shortest path (referred to as SR-ISIS and SR-OSPF).
The global default TTM preference for the tunnel types is as follows:• ROUTE_PREF_RSVP 7• ROUTE_PREF_SR_TE 8• ROUTE_PREF_LDP 9• ROUTE_PREF_OSPF_TTM 10• ROUTE_PREF_ISIS_TTM 11• ROUTE_PREF_BGP_TTM 12• ROUTE_PREF_GRE 255
The default value for SR-ISIS or SR-OSPF is the same regardless if one or more IS-IS or OSPF instances
programmed a tunnel for the same prefix. The selection of a SR tunnel in this case will be based on lowest
IGP instance-id.

Parameters

preference — integer value to represent the preference of IS-IS or OSPF SR tunnels in TTM.
Values

1— 255

Default

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advertise-tunnel-link
Syntax[no] advertise-tunnel-link

Context

config>router>isis

Description

This command enables the forwarding adjacency feature. With this feature, IS-IS or OSPF advertises an
RSVP LSP as a link so that other routers in the network can include it in their SPF computations. The RSVP
LSP is advertised as an unnumbered point-to-point link and the link LSP/LSA has no Traffic Engineering
opaque sub-TLVs per RFC 3906.
The forwarding adjacency feature can be enabled independently from the IGP shortcut feature in CLI. If bothrsvp-shortcut and advertise-tunnel-link options are enabled for a given IGP instance, then the advertisetunnel-link will win.
When the forwarding adjacency feature is enabled, each node advertises a p2p unnumbered link for each best
metric tunnel to the router-id of any endpoint node. The node does not include the tunnels as IGP shortcuts in
SPF computation directly. Instead, when the LSA/LSP advertising the corresponding P2P unnumbered linkis installed in the local routing database, then the node performs an SPF using it like any other link LSA/LSP.
The link bi-directional check requires that a link, regular link or tunnel link, exists in the reverse direction for
the tunnel to be used in SPF.
Note that the igp-shortcut option under the LSP name governs the use of the LSP with both the rsvpshortcut and the advertise-tunnel-link options in IGP. In other words, the user can exclude a specific RSVP
LSP from being used as a forwarding adjacency by entering the command config>router>mpls>lsp>noigp-shortcut.
The resolution and forwarding of IPv6 prefixes to IPv4 forwarding adjacency LSP is not supported.
The no form of this command disables forwarding adjacency and hence disables the advertisement of RSVP
LSP into IGP.

Default

no advertise-tunnel-link

retransmit-interval
Syntaxretransmit-interval seconds
no retransmit-interval

Context

config>router>isis>interface ip-int-name

Description

This command configures the minimum time between LSP PDU retransmissions on a point-to-point interface.
The no form of the command reverts to the default value.

Default
Parameters100
seconds — The interval in seconds that IS-IS LSPs can be sent on the interface.
ValuesPage 578

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spf-wait
Syntax[no] spf-wait spf-wait [spf-initial-wait [spf-second-wait]]

Context

config>router>isis

Description

Default
Parameters

This command defines the maximum interval between two consecutive SPF calculations in seconds. Timersthat determine when to initiate the first, second and subsequent SPF calculations after a topology change
occurs can be controlled with this command. Subsequent SPF runs (if required) will occur at exponentially
increasing intervals of the spf-second-wait interval. For example, if the spf-second-wait interval is 1000,
then the next SPF will run after 2000 milliseconds, and then next SPF will run after 4000 milliseconds, etc.,
until it reaches the spf-wait value. The SPF interval will stay at spf-wait value until there are no more SPF
runs scheduled in that interval. After a full interval without any SPF runs, the SPF interval will drop back to
spf-initial-wait.
no spf-wait
spf-wait — Specifies the maximum interval in seconds between two consecutive spf calculations.
Values

1 — 120

Default10

spf-initial-wait — Specifies the initial SPF calculation delay in milliseconds after a topology change.
Values

10 — 100000

Default

1000

spf-second-wait — Specifies the hold time in milliseconds between the first and second SPF calculation.
Values

1 — 100000

Default

1000

strict-adjacency-check
Syntax[no] strict-adjacency-check

Context

config>router>isis

Description

This command enables strict checking of address families (IPv4 and IPv6) for IS-IS adjacencies. Whenenabled, adjacencies will not come up unless both routers have exactly the same address families configured.
If there is an existing adjacency with unmatched address families, it will be torn down. This command isused to prevent black-holing traffic when IPv4 and IPv6 topologies are different. When disabled (no strictadjacency-check) a BFD session failure for either IPv4 or Ipv6 will cause the routes for the other addressfamily to be removed as well.
When disabled (no strict-adjacency-check), both routers only need to have one common address family toestablish the adjacency.

Default

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summary-address
Syntaxsummary-address {ip-prefix/mask | ip-prefix [netmask]} level [tag tag]no summary-address {ip-prefix/mask | ip-prefix [netmask]}

Context

config>router>isis

Description
Default
Parameters

This command creates summary-addresses.
none
ip-prefix/mask — Specifies information for the specified IP prefix and mask length.
Valuesipv4-prefix:
ipv4-prefix-length:
ipv6-prefix:

ipv6-prefix-length:

a.b.c.d (host bits must be 0)
0 — 32
x:x:x:x:x:x:x:x (eight 16-bit pieces)
x:x:x:x:x:x:d.d.d.dx: [0 — FFFF]H
d: [0 — 255]D[0 — 128]

netmask — The subnet mask in dotted decimal notation.
Values

0.0.0.0 — 255.255.255.255 (network bits all 1 and host bits all 0)

level — Specifies IS-IS level area attributes.
Valueslevel-1, level-2, level-1/2

tag tag — Assigns a route tag to the summary address.
Values

1 – 4294967295

ignore-attached-bit
Syntaxignore-attached-bit[no] ignore-attached-bit

Context

config>router>isis

Description

This command configures IS-IS to ignore the attached bit on received Level 1 LSPs to disable installation ofdefault routes.

suppress-attached-bit
Syntaxsuppress-attached-bit
no suppress-attached-bit

Context

config>router>isis

Description

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This command configures IS-IS to suppress setting the attached bit on originated Level 1 LSPs to prevent all
L1 routers in the area from installing a default route to it.

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IS-IS

traffic-engineering
Syntax[no] traffic-engineering

Context

config>router>isis

Description
Default

This command configures traffic-engineering and determines if IGP shortcuts are required by BGP.
disabled

unicast-import-disable
Syntax[no] unicast-import-disable

Context

config>router>isis

Description

Default

This command allows one IGP to import its routes into RPF RTM while another IGP imports routes only
into the unicast RTM. Import policies can redistribute routes from an IGP protocol into the RPF RTM (themulticast routing table). By default, the IGP routes will not be imported into RPF RTM as such an importpolicy must be explicitly configured.
disabledwide-metrics-only
Syntax[no] wide-metrics-onlyContext

config>router>isis>level level-number

Description

This command enables the exclusive use of wide metrics in the LSPs for the level number.. Narrow metrics
can have values between 1 and 63. IS-IS can generate two TLVs, one for the adjacency and one for the IP
prefix. In order to support traffic engineering, wider metrics are required. When wide metrics are used, a second pair of TLVs are added, again, one for the adjacency and one for the IP prefix.
By default, both sets of TLVs are generated. When wide-metrics-only is configured, IS-IS only generates thepair of TLVs with wide metrics for that level.
The no form of the command reverts to the default value.

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