# Cisco Networking/CCENT/IP Addressing

This lesson covers IP addressing.

## Objectives and Skills

Objectives and skills for the IP addressing portion of Cisco CCENT certification include:
* Describe the operation and necessity of using private and public IP addresses for IPv4 addressing
* Identify the appropriate IPv4 addressing scheme using VLSM and summarization to satisfy addressing requirements in a LAN/WAN environment
* Identify the appropriate IPv6 addressing scheme to satisfy addressing requirements in a LAN/WAN environment
* Describe the technological requirements for running IPv6 in conjunction with IPv4
** Dual stack
* Describe IPv6 addresses
** Global unicast
** Multicast
** Link local
** Unique local
** EUI 64
** Auto-configuration

## Readings

* Wikipedia: IP address
* Wikipedia: Private network
* Wikipedia: Neighbor Discovery Protocol
* Cisco: Internet Protocols
* Wikipedia: IP multicast
* Cisco: IPv6

## Multimedia

* YouTube: Understanding IP Classes - CompTIA Network+ N10-005: 1.3
* YouTube: Classless Inter-Domain Routing - CompTIA Network+ N10-005: 1.3
* YouTube: An overview of IPv4 and IPv6 - CompTIA Network+ N10-005: 1.3
* YouTube: Understanding APIPA - CompTIA Network+ N10-005: 1.3
* Cisco: Understanding the TCP/IP Internet Layer
* Cisco: Introducing IPv6
* Cisco: Transitioning to IPv6

## Activities

* Research IPv4 address classes. Build a table of valid public and private IPv4 address ranges. Then search the Internet for 'verify valid ip address'. Create and test various addresses to see if they are valid or invalid. Does the validator you are using correctly identify public, private, multicast, and experimental address ranges?
* Search the Internet for 'what is my ip'. Identify your public IPv4 address and your public IPv6 address, if you have one. Visit ARIN.net:WhoisRWS or your local regional Internet registry and look up the address registration for your IP addresses. Then search the Internet for 'IPv6 test'. Use several websites to test your IPv6 Internet connection.
* Review Jacob Salmela: Earning IPv6 Certification from Hurricane Electric and the walkthroughs for Newbie and Explorer. Then visit Hurricane Electric: IPv6 Certifications. Register for free IPv6 certification testing and complete the Newbie and Explorer certifications.
* Play the Cisco Binary Game. Practice until you can consistently achieve a high score.

## Lesson Summary

* An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.
* The IP address space is managed by the Internet Assigned Numbers Authority (IANA) and delegated to five regional Internet registries (RIRs).
* The regional Internet Registries are:
** African Network Information Center (AFRINIC) for Africa
** American Registry for Internet Numbers (ARIN) for the United States, Canada, several parts of the Caribbean region, and Antarctica.
** Asia-Pacific Network Information Centre (APNIC) for Asia, Australia, New Zealand, and neighboring countries
** Latin America and Caribbean Network Information Centre (LACNIC) for Latin America and parts of the Caribbean region
** Réseaux IP Européens Network Coordination Centre (RIPE NCC) for Europe, Russia, the Middle East, and Central Asia
* An IP address serves two principal functions: host or network interface identification and location (network) addressing.
* In both IPv4 and IPv6 the high order (leftmost) bits represent the network address and the low order (rightmost) bits represent the host address.
* IPv4 addresses are 32-bit numbers, typically expressed in dotted-decimal notation such as 198.51.100.1.
* In IPv4 dotted-decimal notation, each of the four decimal numbers represents eight bits, with decimal values ranging from 0 to 255.
* IPv4 initially used classful addressing, with fixed network and host address sizes.
* Under class-based addressing, the first octet defined the network and host address sizes as:
** Class A (0 - 127) - 8 bits network, 24 bits host
** Class B (128 - 191) - 16 bits network, 16 bits host
** Class C (192 - 223) - 24 bits network, 8 bits host
** Class D (224 - 239) - Multicast addresses (not used for host addressing)
** Class E (240 - 255) - Experimental (reserved)
* Class-based addressing was replaced with Classless Inter-Domain Routing (CIDR) using variable-length subnet masking (VLSM) in 1993.
* Variable-length subnet masks are defined using either dotted-decimal notation such as 255.255.255.0, or prefix notation, such as /24.
* Private IPv4 address ranges are defined in RFC 1918 as:
** 10.0.0.0/8
** 172.16.0.0/12
** 192.168.0.0/16
* Private networks typically connect to the Internet through network address translation (NAT) or using some kind of proxy server.
* An IPv4 link-local address block is defined as 169.254.0.0/16.
* IPv4 Link-local addresses are used for automatic address assignment in the absence of a static or dynamic address.
* Microsoft refers to automatic address assignment as APIPA.
* IPv4 supports unicast, broadcast, and multicast addressing.
* IPv6 addresses are 128-bit numbers, typically expressed in hexadecimal notation such as 2001:db8:0:1234:0:567:8:1
* In IPv6 addresses, one or more consecutive groups of zero value may be replaced with a single empty group using two consecutive colons (::), such as 2001:db8::1234:0:567:8:1, ::1, or :: (zero).
* In IPv6 hexadecimal notation, each of the hexadecimal groups represents 16 bits, with hexadecimal values ranging from 0 to FFFF.
* Private IPv6 addresses, known as unique local addresses, may be defined using the prefix fc00::/7.
* IPv6 link-local addresses are automatically generated for all interfaces, regardless of static or dynamic address, using the prefix fe80::/10.
* IPv6 multicast addresses use the prefix ff00::/8.
* IPv6 supports unicast, multicast, and anycast addressing.
* IPv6 replaces broadcast addressing with multicast to the specially-defined all-nodes multicast address.
* IPv6 uses the Neighbor Discovery Protocol in place of ARP and defines five ICMPv6 packet types for the purpose of router solicitation, router advertisement, neighbor solicitation, neighbor advertisement, and network redirects.
** Router Solicitation (RS) - Used by hosts to locate routers on an attached link.
** Router Advertisement (RA) - Used by routers to advertise their presence or in response to a Router Solicitation message.
** Neighbor Solicitation (NS) - Used by hosts to determine the link layer address of a neighbor.
** Neighbor Advertisement (NA) - Used by hosts to respond to a Neighbor Solicitation message.
** Redirect - Used by routers to inform hosts of a better first hop router for a destination.
* Mechanisms to transition from IPv4 to IPv6 include dual stack, tunneling, and translation.

## Key Terms
### all-nodes multicast address

    The IPv6 multicast address ff02::1, used to address all nodes on the local network segment.

### all-routers multicast address

    The IPv6 multicast address ff02::2, used to address all routers on the local network segment.

### anycast

    A network addressing and routing methodology in which datagrams from a single sender are routed to nearest node in a group of potential receivers, all identified by the same destination address.

### ARP (Address Resolution Protocol)

    A telecommunication protocol used for resolution of network layer addresses into link layer addresses.

### default router (default gateway)

    The node that is assumed to know how to forward packets on to other networks.

### dual stack

    IP implementations that provide both IPv4 and IPv6 protocol stacks in the same network node.

### Duplicate Address Detection (DAD)

    A test for the uniqueness of an IP address using ARP (IPv4) or Neighbor Solicitation and Neighbor Advertisement (IPv6) messages.

### EUI-64

    A MAC address used in IPv6, generated by translating MAC-48 or EUI-48 addresses into 64-bit values.

### IETF (Internet Engineering Task Force)

    The organization that develops and promotes voluntary Internet standards.

### IPv4 address exhaustion

    The depletion of the pool of unallocated Internet Protocol Version 4 (IPv4) addresses

### link-local

    A network address that is valid only for communications within the network segment (link) or the broadcast domain that the host is connected to.

### solicited-node multicast address

    An IPv6 multicast address created by combining the prefix ff02::1:ff00:0/104 with the last 24 bits of a unicast or anycast address, used by NDP for Neighbor Solicitation messages.

### subnet router anycast address

    The lowest IPv6 address within each subnet prefix, used to contact the nearest router.

## Review Questions

* An Internet Protocol address (IP address) is a _____ assigned to _____. An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.
* The IP address space is managed by _____ and delegated to five _____. The IP address space is managed by the Internet Assigned Numbers Authority (IANA) and delegated to five regional Internet registries (RIRs).
* The regional Internet Registries are: The regional Internet Registries are: African Network Information Center (AFRINIC) for Africa American Registry for Internet Numbers (ARIN) for the United States, Canada, several parts of the Caribbean region, and Antarctica. Asia-Pacific Network Information Centre (APNIC) for Asia, Australia, New Zealand, and neighboring countries Latin America and Caribbean Network Information Centre (LACNIC) for Latin America and parts of the Caribbean region Réseaux IP Européens Network Coordination Centre (RIPE NCC) for Europe, Russia, the Middle East, and Central Asia
* An IP address serves two principal functions: _____ and _____. An IP address serves two principal functions: host or network interface identification and location (network) addressing.
* In both IPv4 and IPv6 the _____ bits represent the _____ address and the _____ bits represent the _____ address. In both IPv4 and IPv6 the high order (leftmost) bits represent the network address and the low order (rightmost) bits represent the host address.
* IPv4 addresses are _____-bit numbers, typically expressed in _____ notation such as _____. IPv4 addresses are 32-bit numbers, typically expressed in dotted-decimal notation such as 198.51.100.1.
* In IPv4 dotted-decimal notation, each of the _____ decimal numbers represents _____ bits, with decimal values ranging from _____ to _____. In IPv4 dotted-decimal notation, each of the four decimal numbers represents eight bits, with decimal values ranging from 0 to 255.
* IPv4 initially used classful addressing, with _____. IPv4 initially used classful addressing, with fixed network and host address sizes.
* Under class-based addressing, the first octet defined the network and host address sizes as: Under class-based addressing, the first octet defined the network and host address sizes as: Class A (0 - 127) - 8 bits network, 24 bits host Class B (128 - 191) - 16 bits network, 16 bits host Class C (192 - 223) - 24 bits network, 8 bits host Class D (224 - 239) - Multicast addresses (not used for host addressing) Class E (240 - 255) - Experimental (reserved)
* Class-based addressing was replaced with _____ using _____ in 1993. Class-based addressing was replaced with Classless Inter-Domain Routing (CIDR) using variable-length subnet masking (VLSM) in 1993.
* Variable-length subnet masks are defined using either _____, or _____. Variable-length subnet masks are defined using either dotted-decimal notation such as 255.255.255.0, or prefix notation, such as /24.
* Private IPv4 address ranges are defined in RFC 1918 as: Private IPv4 address ranges are defined in RFC 1918 as: 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
* Private networks typically connect to the Internet through _____. Private networks typically connect to the Internet through network address translation (NAT).
* The IPv4 link-local address block is defined as _____. The IPv4 link-local address block is defined as 169.254.0.0/16.
* IPv4 Link-local addresses are used for _____. IPv4 Link-local addresses are used for automatic address assignment in the absence of a static or dynamic address.
* Microsoft refers to automatic address assignment as _____. Microsoft refers to automatic address assignment as APIPA.
* IPv4 supports _____, _____, and _____ addressing. IPv4 supports unicast, broadcast, and multicast addressing.
* IPv6 addresses are _____-bit numbers, typically expressed in _____ notation such as _____. IPv6 addresses are 128-bit numbers, typically expressed in hexadecimal notation such as 2001:db8:0:1234:0:567:8:1.
* In IPv6 addresses, one or more consecutive groups of zero value may be replaced with _____. In IPv6 addresses, one or more consecutive groups of zero value may be replaced with a single empty group using two consecutive colons (::), such as 2001:db8::1234:0:567:8:1, ::1, or :: (zero).
* In IPv6 hexadecimal notation, each of the hexadecimal groups represents _____, with hexadecimal values ranging from _____ to _____. In IPv6 hexadecimal notation, each of the hexadecimal groups represents 16 bits, with hexadecimal values ranging from 0 to FFFF.
* Private IPv6 addresses, known as unique local addresses, may be defined using the prefix _____. Private IPv6 addresses, known as unique local addresses, may be defined using the prefix fc00::/7.
* IPv6 link-local addresses are automatically generated for all interfaces, regardless of static or dynamic address, using the prefix _____. IPv6 link-local addresses are automatically generated for all interfaces, regardless of static or dynamic address, using the prefix fe80::/10.
* IPv6 multicast addresses use the prefix _____. IPv6 multicast addresses use the prefix ff00::/8.
* IPv6 supports _____, _____, and _____ addressing. IPv6 supports unicast, multicast, and anycast addressing.
* IPv6 replaces broadcast addressing with _____. IPv6 replaces broadcast addressing with multicast to the specially-defined all-nodes multicast address.
* IPv6 uses _____ in place of ARP and defines five ICMPv6 packet types for the purpose of _____. IPv6 uses the Neighbor Discovery Protocol in place of ARP and defines five ICMPv6 packet types for the purpose of router solicitation, router advertisement, neighbor solicitation, neighbor advertisement, and network redirects. Router Solicitation (RS) - Used by hosts to locate routers on an attached link. Router Advertisement (RA) - Used by routers to advertise their presence or in response to a Router Solicitation message. Neighbor Solicitation (NS) - Used by hosts to determine the link layer address of a neighbor. Neighbor Advertisement (NA) - Used by hosts to respond to a Neighbor Solicitation message. Redirect - Used by routers to inform hosts of a better first hop router for a destination.
* Mechanisms to transition from IPv4 to IPv6 include _____, _____, and _____. Mechanisms to transition from IPv4 to IPv6 include dual stack, tunneling, and translation.

## Assessments

* Flashcards: Quizlet: CCENT - IP Addressing
* Quiz: Quizlet: CCENT - IP Addressing

## See Also

* Internet Protocol Analysis/Internet Layer IPv4
* Internet Protocol Analysis/IPv6
* Internet Protocol Analysis/Multicast