Newsgroup: it.comp.reti.cisco
Titolo: Configurazione ISDN di backup

Hello
Buond�
ho pascolato su internet ma non ho trovato un esempio calzante a quello che 
devo fare io.
Ho un 1841 con 12.4(22) IPBASE IOS, una WIC1T e una WIC ISDN.
Siccome la linea primaria sHDSL V35 cade spesso, vorrei implementare un 
backup ISDN sul ppp @
libero.it
 che mi consenta di navigare mentre la sHDSL � 
down.
Non appena la sHDSL torna up, si riruota il traffico per la sHDSL.
Una volta avevo implementato object tracking ma tra 2 router fisici e con 
HSRP.
Qui con ISDN non so proprio come si pu� fare.
Qualcuno mi da uno stralcio di config da cui partire?
FastEthernet0/0            109.168.2.xxx   First of my public subnet /29
FastEthernet0/1            unassigned      YES NVRAM  administratively down
down
BRI0/0/0                   unassigned      YES NVRAM  administratively down
down
BRI0/0/0:1                 unassigned      YES unset  administratively down
down
BRI0/0/0:2                 unassigned      YES unset  administratively down
down
Serial0/1/0                unassigned      YES NVRAM  up
up
Serial0/1/0.1              109.168.3.xxx   Point to point
On the fast0/0 I have connected a firewall that does nat for all my lan.
Since the sHDSL link goes down very often, I need to setup a dialer
interface to call out when the shdsl doesnt work.
Here is the config.
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname xxxxxxxxxx.dsl.static.ip
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
logging buffered 51200 warnings
!
no aaa new-model
clock timezone CET 2
dot11 syslog
ip source-route
!
!
!
!
ip cef
ip domain name 
kpnqwest.it
ip name-server 212.97.32.2
ip name-server 94.141.24.92
multilink bundle-name authenticated
!
!
crypto pki trustpoint TP-self-signed-1106705543
 enrollment selfsigned
 subject-name cn=IOS-Self-Signed-Certificate-1106705543
 revocation-check none
 rsakeypair TP-self-signed-1106705543
!
!
crypto pki certificate chain TP-self-signed-1106705543
 <SNIP>
!
!
username xxxxxprivilege 15 password 0 xxxxxxx
archive
 log config
  hidekeys
!
!
!
!
!
interface FastEthernet0/0
 description $ETH-LAN$$ETH-SW-LAUNCH$$INTF-INFO-FE 0$
 ip address 109.168.2.xxx 255.255.255.248
 duplex auto
 speed auto
!
interface FastEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface BRI0/0/0
 no ip address
 encapsulation hdlc
 shutdown
!
interface Serial0/1/0
 no ip address
 encapsulation frame-relay IETF
!
interface Serial0/1/0.1 point-to-point
 ip address 109.168.3.xxx 255.255.255.252
 ip nat outside
 ip virtual-reassembly
 snmp trap link-status
 frame-relay interface-dlci 20
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 109.168.3.177
!
no ip http server
ip http authentication local
no ip http secure-server
ip http timeout-policy idle 60 life 86400 requests 10000
!
!
!
!
control-plane
!
banner exec ^C
% Password expiration warning.
-----------------------------------------------------------------------
Cisco Router and Security Device Manager (SDM) is installed on this device
and
it provides the default username "cisco" for  one-time use. If you have
already
used the username "cisco" to login to the router and your IOS image supports
the
"one-time" user option, then this username has already expired. You will not
be
able to login to the router with this username after you exit this session.
It is strongly suggested that you create a new username with a privilege
level
of 15 using the following command.
username <myuser> privilege 15 secret 0 <mypassword>
Replace <myuser> and <mypassword> with the username and password you want to
use.
-----------------------------------------------------------------------
^C
banner login ^C
-----------------------------------------------------------------------
Cisco Router and Security Device Manager (SDM) is installed on this device.
This feature requires the one-time use of the username "cisco"
with the password "cisco". The default username and password have a
privilege level of 15.
Please change these publicly known initial credentials using SDM or the IOS
CLI.
Here are the Cisco IOS commands.
username <myuser>  privilege 15 secret 0 <mypassword>
no username cisco
Replace <myuser> and <mypassword> with the username and password you want to
use.
For more information about SDM please follow the instructions in the QUICK
START
GUIDE for your router or go to 
http://www.cisco.com/go/sdm
-----------------------------------------------------------------------
^C
!
line con 0
 login local
line aux 0
line vty 0 4
 privilege level 15
 login local
 transport input ssh
line vty 5 15
 access-class 23 in
 privilege level 15
 login local
 transport input telnet ssh
!
scheduler allocate 20000 1000
ntp server 192.43.244.18
ntp server 193.204.114.105
end
 

eeehh.... qui è lunga...
allora...
1- configuri la BRI per fare la chiamata:
isdn switch-type basic-net3
interface BRI0/0/0
 ip address negotiated
 ip nat outside
 ip virtual-reassembly
 encapsulation ppp
 dialer string ILNUMERODITELEFONODILIBERO
 dialer-group 1
 isdn switch-type basic-net3
 no cdp enable
 ppp authentication chap callin callout
 ppp chap hostname LATUAUTENZADILIBERO
 ppp chap password
LATUAPASSWORDILIBERO
 ppp multilink
 ppp multilink load-threshold 1 either
dialer-list 1 protocol ip permit
2- Inserisci una default route di backup
ip route 0.0.0.0 0.0.0.0 BRI0/0/0 100
3- Applichi il NAT. Non capisco la tua configurazione cmq se hai una
linea di nat overload verso la seriale, la devi mettere uguale verso
la BRI0/0/0
In questo modo dovrebbe salire la BRI nel caso cada fisicamente la
seriale (cioè se fai "show int serial0/0/0" la vedi up down o down
down). Se l'interfaccia seriale rimane up up ma non ci passa nulla, il
router non fa salire l'ISDN. Per fare questo devi applicare un track
sulla default route primaria che punta alla seriale. Ma se lo
configuri male potresti andare in contro a falsi positivi.
Questo è un esempio:
ip sla monitor 1
 type echo protocol ipIcmpEcho UNIPDAPINGARE(se non ne hai uno statico
allora mettici quello di 
google.com
, 
cisco.com
 o qualcosa che sai che
è sempre su)
 timeout 500
 threshold 3000
 frequency 1
ip sla monitor schedule 1 life forever start-time now
track 1 rtr 1 reachability
ip route 0.0.0.0 0.0.0.0 serial0/0/0 track 1
CIAO

Grazie delle info, per fortuna non ho dovuto poi andare a implementarla :)