The ipv6 summary command configures IS-IS to generate IPv6 aggregated routes.
The undo ipv6 summary command cancels the aggregated routes.
By default, the system does not aggregate routes.
ipv6 summary ipv6-address prefix-length [ avoid-feedback | generate_null0_route | tag tag | [ level-1 | level-1-2 | level-2 ] ] *
undo ipv6 summary ipv6-address prefix-length [ level-1 | level-1-2 | level-2 ]
| Parameter | Description | Value |
|---|---|---|
| ipv6-address | Specifies the address segment of the routes to be aggregated. | - |
| prefix-length | Specifies the length of the prefix of IPv6 address. | It is an integer ranging from 0 to 128. |
| avoid-feedback | Avoids learning aggregated routes through SPF calculation. | - |
| generate_null0_route | Generates NULL0 routes to avoid routing loop. | - |
| tag tag | Specifies the administrative tag value. | The value ranges from 1 to 4294967295. |
| level-1 | Aggregates the routes in the Level-1 area. | - |
| level-1-2 | Aggregates the routes in the Level-1 area and the Level-2 area. | - |
| level-2 | Aggregates the routes in the Level-2 area. NOTE:
If the level is not specified, level-2 is used by default. |
- |
This command is valid only for an IPv6 base topology.
The routes with the same prefix can be aggregated into one route. This can reduce the scale of the routing table, the size of the LSPs generated by the local router, and the scale of the LSDB. The aggregated routes can be the routes discovered by IS-IS or the imported IPv6 routes. After the aggregation, the smallest cost among those of the routes that are aggregated is used as the cost of the aggregated IPv6 route.
The ipv6 summary command can take effect only after IPv6 is enabled for the IS-IS process by the ipv6 enable command.