Enable IS-ISv6 on an Interface
This example shows the minimum configuration required for enabling IS-IS on IPv6 on an interface. R1 and R2 are two routers in the ABC instance connecting to the network 1000::/64. After enabling IS-IS on an interface, create a routing instance, and specify the Network Entity Title (NET). IS-IS explicitly specifies a NET to begin routing. NET is comprised of the area address and the system ID of the router.
Note: ISISv6 session will come up even if IPv6 address is not configured, as it will use the link local address present on the interfaces.
Figure 7-53: Figure 4-46: Basic IS-IS v6 Topology
Configuration
R1
#configure terminal | Enter configure mode. |
(config)#interface eth1 | Enter interface mode. |
(config-if)#ipv6 router isis ABC | Enable IS-ISv6 routing on an interface for area 49(ABC). |
(config-if)#ipv6 address 1000::1/64 | Configure IPv6 address on interface. |
(config-if)#exit | Exit interface mode. |
(config)#router isis ABC | Create an IS-IS routing instance for area 49 (ABC). |
(config-router)#is-type level-2-only | Configure instance as level-2-only routing. |
(config-router)#net 49.0005.0000.0000.0001.00 | Set a Network Entity Title for this instance, specifying the area address and the system ID. |
R2
#configure terminal | Enter configure mode. |
(config)#interface eth1 | Enter interface mode. |
(config-if)#ipv6 router isis ABC | Enable IS-ISv6 routing on an interface for area 49(ABC). |
(config-if)#ipv6 address 1000::2/64 | Configure IPv6 address on interface. |
(config-if)#exit | Exit interface mode. |
(config)#router isis ABC | Create an IS-IS routing instance for area 49 (ABC). |
(config-router)#is-type level-2-only | Configure instance as level-2-only routing. |
(config-router)#net 49.0005.0000.0000.0002.00 | Set a Network Entity Title for this instance, specifying the area address and the system ID. |
Validation
R1#show clns neighbors
Total number of L1 adjacencies: 0
Total number of L2 adjacencies: 1
Total number of adjacencies: 1
Tag ABC: VRF : default
System Id Interface SNPA State Holdtime Type Protocol
0000.0000.0002 eth1 b86a.97c4.31c5 Up 27 L2 IS-IS
R2#show clns neighbors
Total number of L1 adjacencies: 0
Total number of L2 adjacencies: 1
Total number of adjacencies: 1
Tag ABC: VRF : default
System Id Interface SNPA State Holdtime Type Protocol
0000.0000.0001 eth1 b86a.97cb.3ec5 Up 7 L2 IS-IS
R2#
R1#show ipv6 isis route
Codes: C - connected, E - external, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, D - discard, e - external metric
Tag ABC: VRF : default
C 1000::/64 [10]
via ::, eth1
R1#
R2#show ipv6 isis route
Codes: C - connected, E - external, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, D - discard, e - external metric
Tag ABC: VRF : default
C 1000::/64 [10]
via ::, eth1
R2#
R1#
R1#show ipv6 isis topology
Tag ABC: VRF : default
IS-IS paths to level-2 routers
System Id Metric Next-Hop Interface SNPA
0000.0000.0001 --
0000.0000.0002 10 0000.0000.0002 eth1 b86a.97c4.31c5
R1#
R2#show ipv6 isis topology
Tag ABC: VRF : default
IS-IS paths to level-2 routers
System Id Metric Next-Hop Interface SNPA
0000.0000.0001 10 0000.0000.0001 eth1 b86a.97cb.3ec5
0000.0000.0002 --
Last modified date: 08/28/2023