I have CenturyLink Internet service, and they have a 6RD IPv6 deployment where they hand out an IPv6 delegated prefix /56 block to me and allow me to use it as I wish. My Cisco ISR router receives the /56 delegated prefix.
I have multiple VLANs and IPv4 routing on a layer 3 switch (a 3750) and am running an IPv4 DHCP server on it currently to hand out v4 IPs to the end hosts.
I have IPv6 running on the 3750 switch and would like to have it send IPv6 router advertisement packets with prefixes of the /56 delegated prefix that is further subnetted.
For example, if the /56 delegated prefix on the router is 2602:35:AE19:5400::/56, I’d like the 3750 to send router advertisement packets with the following prefixes, one prefix per VLAN:
… and so on.
My plan is to have each host on the VLANs use SLAAC and EUI-64 to generate their globally routable IPv6 address.
I know how to make this setup work if I send the router advertisement messages from the router. Here’s the Cisco code to do that:
ipv6 general-prefix PREFIX-CENTURYLINK 6rd Tunnel1 ipv6 unicast-routing ipv6 multicast-routing ipv6 cef ipv6 route 2602::/24 Tunnel1 interface Tunnel1 description CENTURYLINK IPV6 6RD TUNNEL no ip address ip mtu 1452 ip tcp adjust-mss 1432 ipv6 enable ipv6 mtu 1432 ipv6 tcp adjust-mss 1412 tunnel source Dialer1 tunnel mode ipv6ip 6rd tunnel path-mtu-discovery tunnel 6rd prefix 2602::/24 tunnel 6rd br <BR-IP-ADDRESS> exit interface GigabitEthernet0/0.1 ipv6 enable ipv6 address autoconfig ipv6 address PREFIX-CENTURYLINK 0:0:0:1::/64 eui-64 ipv6 nd autoconfig prefix ipv6 nd autoconfig default-route exit interface GigabitEthernet0/0.2 ipv6 enable ipv6 address autoconfig ipv6 address PREFIX-CENTURYLINK 0:0:0:2::/64 eui-64 ipv6 nd autoconfig prefix ipv6 nd autoconfig default-route exit interface GigabitEthernet0/0.3 ipv6 enable ipv6 address autoconfig ipv6 address PREFIX-CENTURYLINK 0:0:0:3::/64 eui-64 ipv6 nd autoconfig prefix ipv6 nd autoconfig default-route exit
Is there some combination of DHCPv6 relay, DHCPv6 client, DHCPv6 prefix delegation (separate but related to 6rd delegated prefixes) and IPv6 router advertisements to achieve what I’m trying to do?