IPv6 router advertisements

You can configure an IPv6 subinterface to originate Router Advertisement (RA) messages. The following settings can be configured for the RA messages:

  • Current hop limit to advertise in the RA messages.

  • IP MTU. Hosts can associate the IP MTU with the link on which the RA messages are received.

  • Managed configuration flag. When enabled, this setting indicates that hosts should use DHCPv6 to obtain IPv6 addresses.

  • Other configuration flag. When enabled, this setting indicates that hosts should use DHCPv6 to obtain other configuration information (besides addresses).

  • The maximum and minimum time between sending router advertisement messages to the all-nodes multicast address.

  • IPv6 prefix list. Hosts that support Stateless Address Auto-Configuration (SLAAC) can use the IPv6 prefixes in the RA messages to generate IPv6 addresses.

  • Number of milliseconds advertised for the reachable time and the retransmit time in RA messages, which hosts use for address resolution and the ICMPv6 Neighbor Unreachability Detection algorithm.

  • Number of seconds advertised as the router lifetime in RA messages. This setting indicates amount of time the advertising router can be used as a default router/gateway.

Configuring IPv6 router advertisements

The following example configures the SR Linux to originate RA messages from an IPv6 subinterface. The RA messages include an IPv6 prefix that SLAAC-enabled clients can use to generate IPv6 addresses.

--{ * candidate shared default }--[  ]--
# info interface ethernet-1/1 subinterface 1 ipv6 router-advertisement
    interface ethernet-1/1 {
        subinterface 1 {
            ipv6 {
                router-advertisement {
                    router-role {
                        admin-state enable
                        prefix 2001:db8:0:b::/64 {
                        }
                    }
                }
            }
        }
    }