DHCP-PD configuration assistance

Hi there,

The following configuration snippet successfully requests a /56 IPv6 prefix from my ISP (IPv4 config also works fine):

vyos@vyos# show interfaces pppoe
 pppoe pppoe0 {
     authentication {
         password XXXXXX
         user XXXXXX
     default-route auto
     description OUTSIDE
     dhcpv6-options {
         pd 0 {
             interface eth3 {
                 address 2
                 sla-id 1
             length 64
     firewall {
         in {
             ipv6-name OUTSIDE-IN-6
             name OUTSIDE-IN
         local {
             ipv6-name OUTSIDE-LOCAL-6
             name OUTSIDE-LOCAL
     ipv6 {
     mtu 1500
     source-interface eth4.10

Version: VyOS 1.3-rolling-202101010217

eth3 is assigned the full /56 prefix (see below). How do I assign it just a 64? I’m planning to add more VLANs once this is working. Cheers

vyos@vyos:~$ show interfaces
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface        IP Address                        S/L  Description
---------        ----------                        ---  -----------
eth1             -                                 u/D
eth2             -                                 u/D
eth3                      u/u  INSIDE
eth4             -                                 u/u
eth4.10          -                                 u/u
eth5             -                                 u/D
eth6             -                                 u/D
lo                            u/u
pppoe0           xxx.xxx.xxx.240/32                 u/u  OUTSIDE

I hacked up a solution that works for home but I wouldn’t run it elsewhere. When I get some more time, I’ll try to diagnose the issue properly. Here’s what I ended up doing:

  • Set a static IPv6 address on the LAN interface (/64)

  • Configure PPPoE PD on a disconnected interface (eth2) where it is still assigned a full /56. Without this, the PPPoE to ISP connection isn’t set up properly.
    (set interfaces pppoe pppoe0 dhcpv6-options pd 0 interface eth2 sla-id 2)

  • Configure RA on the LAN interface to distribute addresses & config etc.

I’ll look at adding additional VLANs in the weekend as well.