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

    The 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).

  • max-advertisement-interval

    The maximum time between sending RA messages to the all-nodes multicast address.

  • min-advertisement-interval

    The minimum time between sending RA messages to the all-nodes multicast address.

  • prefix

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

  • reachable-time

    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.

  • router-lifetime

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

  • dns-options server

    When recursive DNS server addresses are enabled, the advertising router sends up to four IPv6 unicast addresses to the host for recursive DNS resolution.

  • dns-options rdnss-lifetime

    The lifetime of the recursive DNS server can be optionally configured. The default value is set to three times the max-advertisement-interval value.

Configuring IPv6 router advertisements

You can configure 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 with-context interface ethernet-1/1
    interface ethernet-1/1 {
        admin-state enable
        subinterface 1 {
            ipv6 {
                admin-state enable
                router-advertisement {
                    router-role {
                        admin-state enable
                        prefix 2001:db8:0:b::/64 {
                        }
                        dns-options {
                            rdnss-lifetime 10
                            server [
                                2001:db8::1
                            ]
                        }
                    }
                }
            }
        }
    }