Configure IPv6 Static Routes for Load Sharing and Redundancy

You can configure multiple static routes to the same destination as load sharing or backup routes.

About this task

If you configure more than one static route to the same destination with different next-hop gateways but the same metrics, the router load balances among the routes using a basic round-robin method.

If you configure multiple static IP routes to the same destination with different next-hop gateways and different metrics, the router always uses the route with the lowest metric. If this route becomes unavailable, the router fails over to the static route with the next-lowest metric.

Two static routes to same destination

Note

You can also use administrative distance to set route priority. Assign the static route a lower administrative distance than other types of routes, unless you want the other route types to be preferred over the static route.

1. Access global configuration mode.
   

   device# configure terminal
   

2. Enter multiple routes to the same destination using different next hops.
   

   device(config)# ipv6 route 2001:DB8::0/64 2001:DB8:2343:0:ee44::1
   device(config)# ipv6 route 2001:DB8::0/64 2001:DB8:2344:0:ee44::2
   

   This example creates two next-hop gateways for all 2001:DB8::0/64 destinations. Traffic alternates between the two paths.
3. To prioritize multiple routes, use different metrics for each possible next hop.
   

   device(config)# ipv6 route 2001:DB8::0/64 2001:DB8:2343:0:ee44::1
   device(config)# ipv6 route 2001:DB8::0/64 2001:DB8:2344:0:ee44::2 2
   

   This example creates an alternate route to all 2001:DB8::0/64 destinations. The primary route uses 2001:DB8:2343:0:ee44::1 as the next hop. The route has the default metric of 1 (the default metric is not entered in the CLI). If this path is not available, traffic is directed through 2001:DB8:2344:0:ee44::2, which has the next lowest metric of 2.