Originate Default Route to ISISv6 Neighbors
This example shows how to originate default route present to ISISv6 neighbors.
Note: To get a default route in ISIS, we must have it (said default route) in the routing table first.To get a default route in ISIS, we should have it (said default route) in the routing table first otherwise we can use the CLI "default information originate always" which advertises default route.
Topology
Figure 7-61: Basic IS-ISv6 Topology
Configuration
R1
#configure terminal | Enter configure mode. |
(config)#ipv6 route ::/0 2345::2 | Configure default route. |
(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)#exit | Exit interface mode. |
(config)#interface eth2 | Enter interface mode. |
(config-if)#ipv6 address 2345::1/64 | Configure IPv6 address on interface. |
(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 49.0001.0000.0000.0001.00 | Set a Network Entity Title for this instance, specifying the area address and the system ID. |
(config-router)#address-family ipv6 | Enter ipv6 address family. |
(config-router-af)#default-information originate | Originate reachability information to Default destination into LSP. |
(config-router-af)#end | Exit all modes and enter privilege mode. |
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)#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. |
(config-router)#end | Exit current mode and enter privilege mode |
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
0000.0000.0001 eth1 b86a.97cb.3ec5 Up 6 L2 IS-IS
R2#
R2#show ipv6 route isis
IP Route Table for VRF "default"
i L2 ::/0 [115/10] via fe80::ba6a:97ff:fecb:3ec5, eth1, 00:09:12
R2#
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
L2 ::/0 [10]
via fe80::ba6a:97ff:fecb:3ec5, eth1
R2#
R2#show isis database verbose
Tag ABC: VRF : default
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
0000.0000.0001.00-00 0x00000006 0x5FA4 1033 0/0/0
Area Address: 49.0001
NLPID: 0x8E
Metric: 10 IS 0000.0000.0001.01
Metric: 0 IPv6 ::/0
0000.0000.0001.01-00 0x00000001 0x21B9 628 0/0/0
Metric: 0 IS 0000.0000.0001.00
Metric: 0 IS R2.00
R2.00-00 * 0x00000002 0xFBED 633 0/0/0
Area Address: 49.0001
NLPID: 0x8E
Hostname: R2
Metric: 10 IS 0000.0000.0001.01
Last modified date: 08/28/2023