Configuration on IS-IS over IPv6

Introduction

This document provides a sample configuration for Intermediate System-to-Intermediate System (IS-IS) over IP version 6 (IPv6). It also discusses how to verify and troubleshoot the configuration.

Requirements

Before you attempt this configuration, ensure that you meet these requirements:

• A basic understanding of IS-IS. For more information, refer to Configuring IS-IS for IP on Cisco Routers.
• A basic understanding of IPv6. For more information.

Components Used

The information in this document is based on these software and hardware versions:

• 12.2(13)T with Enterprise feature set
• Cisco 7200 Platform

The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it.

Configure

In this section, you are presented with the information to configure the features described in this document.

Network Diagram

This document uses the network setup shown in the diagram below.

Configurations

This document uses the configurations shown below.

• c7200-1
• c7200-2

c7200-1# show run

ipv6 unicast-routing 
! Enable the forwarding of IPv6 unicast datagrams
!
interface Loopback0
 no ip address
 ipv6 address 2000:1::1/96
 circuit-type level-2-only
 address-family ipv6 unicast
!

!--- If the sole purpose of the loopback is a router ID, !--- a /128 is preferred. !--- A /96 is used here to advertise this route through IS-IS. !--- Last two commands for getting advertised in the LSP


 ipv6 router isis alpha

!--- Enables IS-IS on the interface for area "alpha."

!
interface FastEthernet3/0
 ip address 172.16.88.51 255.255.255.224
 duplex half
 ipv6 address 1000:1:1:1:1:1:1:1/112
 ipv6 router isis alpha
!
router isis alpha

!--- Enables the IS-IS routing process for area "alpha."

 net 49.1111.2220.3330.4440.00

!--- Defines the area addresses for the IS-IS area and the system ID !--- of the router. 49.1111 is the area id SysID is 2220.3330.4440.

!
end

c7200-2# show run
ipv6 unicast-routing
!
interface Loopback0                                                  
 no ip address
 ipv6 address 3000:1::1/96
 ipv6 router isis alpha
!
interface FastEthernet0/0
 ip address 172.16.88.50 255.255.255.224
 duplex auto
 speed auto
 ipv6 address 1000:1:1:1:1:1:1:2/112
 ipv6 router isis alpha
!
 router isis alpha
 net 49.1111.2222.3333.4444.00
 !
end



Verify

This section provides information you can use to confirm your configuration is working properly.

Certain show commands are supported by the Output Interpreter Tool,  which allows you to view an analysis of showcommand output.


show clns interface- Used to list the Connectionless Network Service (CLNS)-specific information about interface

c7200-1# show clns int fa3/0 
FastEthernet3/0 is up, line protocol is up 
  Checksums enabled, MTU 1497, Encapsulation SAP 
  ERPDUs enabled, min. interval 10 msec. 
  CLNS fast switching enabled 
  CLNS SSE switching disabled 

  DEC compatibility mode OFF for this interface 
  Next ESH/ISH in 43 seconds 
  Routing Protocol: IS-IS 
    Circuit Type: level-1-2 
    Interface number 0x0, local circuit ID 0x1 
    Level-1 Metric: 10, Priority: 64, Circuit ID: c7200-1.01      
    Number of active level-1 adjacencies: 1 
    Level-2 Metric: 10, Priority: 64, Circuit ID: c7200-1.01      
    Number of active level-2 adjacencies: 1 
    Next IS-IS LAN Level-1 Hello in 1 seconds 
    Next IS-IS LAN Level-2 Hello in 1 seconds



show clns neighbors - Used to show the CLNS neighbors state.

c7200-1# show clns neighbors
System Id      Interface   SNPA                     State  Holdtime  Type Protocol 
c7200-2        Fa3/0       0004.281e.e008           Up      25        L1L2 IS-IS



show ipv6 route - Used to verify if a route exists on the IPv6.

c7200-1# show ipv6 route 
     IPv6 Routing Table - 7 entries 
     Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP 
            U - Per-user Static route 
            I1 - ISIS L1, I2 - ISIS L2, IA - ISIS      interarea 
     L   1000:1:1:1:1:1:1:1/128 [0/0] 
          via ::, FastEthernet3/0 
     C   1000:1:1:1:1:1:1:0/112 [0/0] 
          via ::, FastEthernet3/0 
     L   2000:1::1/128 [0/0] 
          via ::, Loopback0 
     C   2000:1::/96 [0/0] 
          via ::, Loopback0 
     I1  3000:1::/96 [115/20] 
          via FE80::204:28FF:FE1E:E008, FastEthernet3/0 
     L   FE80::/10 [0/0] 
          via ::, Null0 
     L   FF00::/8 [0/0] 
          via ::, Null0

c7200-1# show ipv6 route 3000:1::1 
     IPv6 Routing Table - 7 entries 
     Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP 
            U - Per-user Static route 
            I1 - ISIS L1, I2 - ISIS L2, IA - ISIS      interarea 
     I1  3000:1::/96 [115/20] 
          via FE80::204:28FF:FE1E:E008, FastEthernet3/0 



show isis database detail - Used to show the IS-IS database details.

c7200-1# show isis database detail
IS-IS Level-1 Link State Database: 
     LSPID                      LSP Seq Num  LSP Checksum  LSP Holdtime           ATT/P/OL 
     c7200-1.00-00       * 0x000000DB        0xC383        1103                   0/0/0 
       Area Address: 49.1111 
       NLPID:        0x8E 
       Hostname: c7200-1 
       IPv6 Address: 2000:1::1 
       Metric: 10         IPv6 1000:1:1:1:1:1:1:0/112      
       Metric: 10         IPv6 2000:1::/96      
       Metric: 10         IS c7200-1.01      
     c7200-1.01-00       * 0x000000D8        0x5C9A        1078                   0/0/0 
       Metric: 0          IS      c7200-1.00 
       Metric: 0          IS      c7200-2.00 
     c7200-2.00-00         0x000000DD        0x0219        757                    0/0/0 
       Area Address: 49.1111 
       NLPID:        0x8E 
       Hostname: c7200-2 
       IPv6 Address: 3000:1::1 
       Metric: 10         IPv6 1000:1:1:1:1:1:1:0/112      
       Metric: 10         IPv6 3000:1::/96      
       Metric: 10         IS c7200-1.01      
     IS-IS Level-2 Link State Database: 
     LSPID                      LSP Seq Num  LSP Checksum  LSP Holdtime           ATT/P/OL 
     c7200-1.00-00       * 0x000000DC        0x2569        893                    0/0/0 
       Area Address: 49.1111 
       NLPID:        0x8E 
       Hostname: c7200-1 
       IPv6 Address: 2000:1::1 
       Metric: 10         IS c7200-1.01      
       Metric: 10         IPv6 1000:1:1:1:1:1:1:0/112      
       Metric: 10         IPv6 2000:1::/96      
       Metric: 20         IPv6 3000:1::/96      
     c7200-1.01-00       * 0x000000D9        0xE994        773                    0/0/0 
       Metric: 0          IS      c7200-1.00 
       Metric: 0          IS      c7200-2.00 
     c7200-2.00-00         0x000000DF        0x88E8        937                    0/0/0 
       Area Address: 49.1111 
       NLPID:        0x8E 
       Hostname: c7200-2 
       IPv6 Address: 3000:1::1 
       Metric: 10         IS c7200-1.01      
       Metric: 10         IPv6 1000:1:1:1:1:1:1:0/112      
       Metric: 20         IPv6 2000:1::/96      
       Metric: 10         IPv6 3000:1::/96



ping - Used to determine if a remote host is active or inactive, and the round-trip delay in communicating with the host.

7200-2# ping 1000:1:1:1:1:1:1:1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1000:1:1:1:1:1:1:1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms