Configuring IPv6 router advertisement

When IPv6 unicast routing is enabled on the routing switch, RAs are transmitted on all IPv6-enabled VLANs or tunnels unless explicitly suppressed globally or per-VLAN. The following steps provide a general outline of the steps for configuring the routing switch for nondefault RA operation on all IPv6-enabled VLANs or tunnels:

Procedure
  1. Enable IPv6 routing on your network.
  2. Enable IPv6 unicast routing. (This must be enabled to allow configuration of other routing protocols). Switch(config)# ipv6 unicast-routing.
  3. Configure the desired per-VLAN or per-tunnel RA operation:
    1. Use the M-bit and O-bit settings to specify the source for IPv6 host configuration; see page VLAN or tunnel context ND configuration:
      1. M-bit setting:

        • Get configuration from RAs (default).

        • Get configuration from DHCPv6.

      2. O-bit setting (applies only if M-bit setting is left in default state):

        • Use RA source for global unicast prefixes (default).

        • Do not use the RA for nonprefix configuration.

    2. Configure global unicast prefix assignments.

      1. Specify any prefixes not configured on the routing switch VLAN or tunnel interface that should be transmitted in RAs to IPv6 hosts on the VLAN.

      2. Deny any prefixes configured on the routing switch VLAN or tunnel interface that should not be transmitted in RAs to IPv6 hosts on the VLAN. Default: Global unicast prefixes configured on the routing switch VLAN interface are included in RAs.

    3. Configure the maximum and minimum interval for transmitting router advertisements on the VLAN; see page ipv6 nd ra prefix.
      NOTE:

      The routing switch also transmits RAs when it receives router solicitations from a host. Autoconfiguration must be enabled on the host before it will generate router solicitations on the VLAN or tunnel.

    4. Configure the ND policy for hosts on the VLAN or tunnel to use:

      1. Hop-limit; Default; 64, see page ipv6 nd ra hop-limit.

      2. Default router lifetime; Default: 1800 seconds, see page ipv6 nd ra prefix.

      3. Reachable time duration to advertise for confirmed neighbors; Default: unspecified (0); see page ipv6 nd ra ns-interval.

      4. Retransmit time to advertise for neighbor solicitations; Default: unspecified (0); see page ipv6 nd ra ns-interval.

    5. Configure per-VLAN RA suppression for any VLAN or tunnel on which you do not want the routing switch to transmit RAs. See page show ipv6 nd ra. 
      Switch(vlan-1)# ipv6 nd ra suppress
Switch(tunnel-3)# ipv6 nd ra suppress