[c-nsp] IPv6-PD over PPPoE in VRF

Sander Steffann sander at steffann.nl
Mon Feb 4 10:39:26 EST 2019


I need some help with a weird problem. I'm working on a setup where we need to do IPv6-PD over PPPoE with dynamic VRF assignment. So we don't know the VRF up front, we get it from RADIUS. We have everything working for IPv4, but IPv6 breaks. This is the RADIUS response we send:

(58) Sent Access-Accept Id 3
(58)   Framed-Protocol = PPP
(58)   Framed-Compression = Van-Jacobson-TCP-IP
(58)   Framed-IP-Address =
(58)   Framed-IP-Netmask =
(58)   Cisco-AVPair = "lcp:interface-config=bandwidth 100000"
(58)   Cisco-AVPair = "lcp:interface-config=vrf forwarding vpn3000"
(58)   Cisco-AVPair = "lcp:interface-config=ip unnumbered Loopback3000"
(58)   Delegated-IPv6-Prefix = 2001:db8::/48
(58)   Cisco-AVPair = "ip:dns-servers="
(58)   Service-Type = Framed-User
(58) Finished request

Without the lcp:interface-config=vrf line it works just fine. RA is sent, CPE sends DHCPv6 discover and gets delegated their /48. But with the VRF config IPv6 gets stuck in the tentative state and never comes up.

I used to see this behaviour on a c7200. When we encountered it we just gave up considering the age of that platform. But to my surprise I'm now seeing exactly the same on an ASR1001X with IOS-XE 16.7... Has anybody ever gotten per-PPPoE-user VRF and DHCPv6-PD to work together?


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