Configure IS-ISv6 Basic Function

Network Requirements

Configure the IS-ISv6 protocol to realize the network interconnection between devices.
Device1 is the Level-1 router and Device2 is the Level-1-2 router. Device1 and Device2 are in the same area, Area 10. Device3 is the Level-2 router in Area 20. Device2 connects the two areas.

Network Topology

Networking of configuring the IS-ISv6 basic functions

Figure 10–1 Networking of configuring the IS-ISv6 basic functions

Configuration Steps

Step 1: Configure the IPv6 address of the interfaces. (Omitted)

Step 2: Configure the IS-ISv6 and enable the process on the interface.

#Configure the IS-ISv6 process as 100, area number as 10, and type as Level-1 and enable the process on the interface of Device1.

Device1#configure terminal
Device1(config)#router isis 100
Device1(config-isis)#net 10.0000.0000.0001.00
Device1(config-isis)#is-type level-1
Device1(config-isis)#metric-style wide
Device1(config-isis)#address-family ipv6 unicast
Device1(config-isis-af)#multi-topology
Device1(config-isis-af)#exit-address-family
Device1(config-isis)#exit
Device1(config)#interface gigabitethernet 0
Device1(config-if-gigabitethernet0)#ipv6 router isis 100
Device1(config-if-gigabitethernet0)#exit
Device1(config)#interface gigabitethernet 1
Device1(config-if-gigabitethernet1)#ipv6 router isis 100
Device1(config-if-gigabitethernet1)#exit

#Configure the IS-ISv6 process as 100, area number as 10, and type as Level-1-2 and enable the process on the interface of Device2.

Device2#configure terminal
Device2(config)#router isis 100
Device2(config-isis)#net 10.0000.0000.0002.00
Device2(config-isis)#metric-style wide
Device2(config-isis)#address-family ipv6 unicast
Device2(config-isis-af)#multi-topology
Device2(config-isis-af)#exit-address-family
Device2(config-isis)#exit
Device2(config)#interface gigabitethernet 0
Device2(config-if-gigabitethernet0)#ipv6 router isis 100
Device2(config-if-gigabitethernet0)#exit
Device2(config)#interface gigabitethernet 1
Device2(config-if-gigabitethernet1)#ipv6 router isis 100
Device2(config-if-gigabitethernet1)#exit

#Configure the IS-ISv6 process as 100, area number as 20, and type as Level-2 and enable the process on the interface of Device3.

Device3#configure terminal
Device3(config)#router isis 100
Device3(config-isis)#net 20.0000.0000.0003.00
Device3(config-isis)#is-type level-2
Device3(config-isis)#metric-style wide
Device3(config-isis)#address-family ipv6 unicast
Device3(config-isis-af)#multi-topology
Device3(config-isis-af)#exit-address-family
Device3(config-isis)#exit
Device3(config)#interface gigabitethernet0
Device3(config-if-gigabitethernet0)#ipv6 router isis 100
Device3(config-if-gigabitethernet0)#exit
Device3(config)#interface gigabitethernet1
Device3(config-if-gigabitethernet1)#ipv6 router isis 100
Device3(config-if-gigabitethernet1)#exit

Step 3: Check the result.

#View the IS-ISv6 neighboring information of Device1.

Device1#show isis neighbors  
IS-IS Instance 100 Neighbors (Counter 1): 
Type    System ID       Interface              State Holdtime Level IETF-NSF Priority Circuit ID 
L1-LAN  0000.0000.0002  gigabitethernet0/2/1   Up    25 sec   L1    capable  64       0000.0000.0001.02

#View the IS-ISv6 neighboring information on Device2.

 Device2#show isis neighbors  
IS-IS Instance 100 Neighbors (Counter 2): 
Type   System ID      Interface             State Holdtime Level IETF-NSF Priority Circuit ID 
L1-LAN 0000.0000.0001 gigabitethernet0/2/0  Up    8 sec    L1    capable  64	   0000.0000.0001.02 
L2-LAN 0000.0000.0003 gigabitethernet0/2/1  Up    7 sec    L2    capable  64       0000.0000.0003.01

Device2 builds the IS-ISv6 neighbor with Device1 and Device3, respectively.

#View the IS-ISv6 neighboring information of Device3.

Device3#show isis neighbors  
IS-IS Instance 100 Neighbors (Counter 1): 
Type   System ID      Interface            State Holdtime Level IETF-NSF Priority Circuit ID 
L2-LAN 0000.0000.0002 gigabitethernet0/2/0 Up    23 sec   L2    capable  64       0000.0000.0003.01

#View the routing information of Device1.

Device1#show ipv6 route 
Codes: C - Connected, L - Local, S - static, R - RIP, B - BGP, i-ISIS 
       U - Per-user Static route 
       O - OSPF, OE-OSPF External, M - Management 
 
i ::/0 [115/10] 
     via fe80::201:7aff:fe5e:6d45, 00:03:17, gigabitethernet0/2/1 
L ::1/128 [0/0] 
     via ::, 16:03:18, lo0 C 2001:1::/64 [0/0] 
     via ::, 00:20:11, gigabitethernet0/2/0 L 2001:1::1/128 [0/0] 
     via ::, 00:20:10, lo0 C 2001:2::/64 [0/0] 
     via ::, 00:19:50, gigabitethernet0/2/1 L 2001:2::1/128 [0/0] 
     via ::, 00:19:49, lo0 
i 2001:3::/64 [115/20] 
     via fe80::201:7aff:fe5e:6d45, 00:06:48, gigabitethernet0/2/1 
 
Device1#show isis ipv6 route  
IS-IS Instance 100, VRF Kernel, IPv6 routes table (Counter 4):
L1 ::/0, flags none, metric 10, from learned, installed 
     via fe80::201:7aff:fe5e:6d45, gigabitethernet1, neighbor 0000.0000.0002
L1 2001:1::/64, flags none, metric 10, from network connected 
     via ::, gigabitethernet0 
L1 2001:2::/64, flags none, metric 10, from network connected 
     via ::, gigabitethernet1 
L1 2001:3::/64, flags none, metric 20, from learned, installed 
     via fe80::201:7aff:fe5e:6d45, gigabitethernet1, neighbor 0000.0000.0002

A default routing is in the routing table of Device1 and the next hop is Device2.

#View the routing information of Device2.

Device2#show ipv6 route 
Codes: C - Connected, L - Local, S - static, R - RIP, B - BGP, i-ISIS 
       U - Per-user Static route 
       O - OSPF, OE-OSPF External, M - Management 
 
L ::1/128 [0/0] 
     via ::, 1d:12:42:31, lo0 
i 2001:1::/64 [115/20] 
     via fe80::201:7aff:fe61:7a24, 00:08:32, gigabitethernet0/2/0 
C 2001:2::/64 [0/0] 
     via ::, 23:41:09, gigabitethernet0/2/0
L 2001:2::2/128 [0/0] 
     via ::, 23:41:06, lo0
C 2001:3::/64 [0/0] 
     via ::, 17:39:09, gigabitethernet0/2/1
L 2001:3::1/128 [0/0] 
     via ::, 17:39:06, lo0 
i 2001:4::/64 [115/20] 
     via fe80::2212:1ff:fe01:101, 00:04:52, gigabitethernet0/2/1 
 
Device2#show isis ipv6 route  
IS-IS Instance 100, VRF Kernel, IPv6 routes table (Counter 4):
L1 2001:1::/64, flags none, metric 20, from learned, installed 
     via fe80::201:7aff:fe61:7a24, gigabitethernet0, neighbor 0000.0000.0001
L1 2001:2::/64, flags none, metric 10, from network connected 
     via ::, gigabitethernet0/2/0 
L1 2001:3::/64, flags none, metric 10, from network connected 
     via ::, gigabitethernet0/2/1 
L2 2001:4::/64, flags none, metric 20, from learned, installed 
     via fe80::2212:1ff:fe01:101, gigabitethernet1, neighbor 0000.0000.0003

Device2 contains the Level-1 and Level-2 routing.

#View the routing information of Device3.

Device3#show ipv6 route 
Codes: C - Connected, L - Local, S - static, R - RIP, B - BGP, i-ISIS 
 
       U - Per-user Static route 
       O - OSPF, OE-OSPF External, M - Management 
 
L ::1/128 [0/0] 
     via ::, 00:00:12, lo0 
i 2001:1::/64 [115/30] 
     via fe80::201:7aff:fe5e:6d46, 00:00:12, gigabitethernet0/2/0
i 2001:2::/64 [115/20] 
     via fe80::201:7aff:fe5e:6d46, 00:00:12, gigabitethernet0/2/0 
C 2001:3::/64 [0/0] 
     via ::, 00:00:12, gigabitethernet0/2/0
L 2001:3::2/128 [0/0] 
     via ::, 00:00:12, lo0
C 2001:4::/64 [0/0] 
     via ::, 00:00:12, gigabitethernet0/2/1
L 2001:4::1/128 [0/0] 
     via ::, 00:00:12, lo0 
 
Device3#show isis ipv6 route  
IS-IS Instance 100, VRF Kernel, IPv6 routes table (Counter 4):
L2 2001:1::/64, flags none, metric 30, from learned, installed 
     via fe80::201:7aff:fe5e:6d46, gigabitethernet0, neighbor 0000.0000.0002
L2 2001:2::/64, flags none, metric 20, from learned, installed 
     via fe80::201:7aff:fe5e:6d46, gigabitethernet0, neighbor 0000.0000.0002
L2 2001:3::/64, flags none, metric 10, from network connected 
     via ::, gigabitethernet0/2/0 
L2 2001:4::/64, flags none, metric 10, from network connected 
     via ::, gigabitethernet0/2/1

Device3 learns the Level-1 route and the Level-1 leaks the route to Level-2 by default.

The metric type is the narrow metric by default. The wide metric is recommended.
The IS-ISv6 route can be learnt only when the multi-topology is used.
The IS-ISv6 entity attribute is Level-1-2 by default.