IPv6 Problems


Hello to all,
we are using vyatta 6.5 since a long time with the IPv4 protocoll and all that we need (firewall, portforw. rdp etc) is working fine. Now we changing to new ISP, how give only IPv6. Our router is sitting behind a modem and show on eth0 (internetsite) a IP6-adress/64. Now my question: Can someone give me an tutorial, how get IP6-(routing) to work with the internal 3 LANs? From the router itself i dont reach any ip6.domain (..there are no such host...) IPv6-forwarding is on, but nothing to see. I am a liitle bit lost in this situation, because we cant reach out our devices inside the lan by IP4 so we MUST change to IPv6.
I hope someone can help me.


What ISP is this, and how do they propose you get access to ipv4 only systems? They must be running some sort of 6-to-4 gateway, in combination with dns servers that convert A records to AAAA records pointing into their gateway.

ipv6 routing is easy, but if you have ipv4 only networks behind this router, and your vyos does not have any ipv4 route for, you won’t have any ipv4 connectivity.

Can you convert ALL your internal machines to ipv6 only? Even then, this is not going to end well.


hello carl, thx for reply. i think i have to made a more precise description of my problem. my ISP is unitymedia and we got a cablemodem. on the internetside we get a IP6-adress ca01:::/64 and an dynamic IP4-adress. But inside (after modem) we receive a semiprivate 10.66.x.x adress so we can`t reach our LAN-devices via port forwarding anymore. So my intension is to use the IP6-adress to get access via this from another IPv6-LAN to my devices.And my problem is, how to setup my vyos/vyatta to route IP6 from outside to inside. is this a little bit clearer ? thx for answering


What brand/model of cable modem? You mention seeing the addresses on the internet side of the cable modem, so presumably you have some (web based?) access to the configuration of that cable modem. Do you have the admin password - can you reconfigure that cable modem? If so, can you put it in bridge mode? That way you have

unitymedia -> cable -> cablemodem -> ethernet -> vyos router ethernet interface

In that configuration, if the vyos router interface is setup for dhcp, you should get the dynamic ip4 address. And with ‘set interfaces ethernet TXT ipv6 address autoconf’ it should also pickup the ipv6 /64 via RA from unitymedia.


@carl: thank you for give a little “inspiration”. no i can`t access to the cable modem, i had a fritzbox at the client-side of the modem for testing and in the setup of the box i have seen the ipv6-address and this private 10.66… assigned from unitymedia.
Yes , my configuration seems like this unitymedia -> cable -> cablemodem -> ethernet -> vyos router ethernet interface ! You wrote ‘set interfaces ethernet TXT ipv6 address autoconf’ <-- i have tried only the autoconf-command and can see an IP6-adress on the ethernetsite to the cablemodem. When i ping from the vyos router itself to an ip6 (google) nothing happens. “…no such host” is the answer. this is what is killing my brain :=( because i have no ipv6-firewall setups in the router for the moment. With IP4 it works like a charm. any suggestions
thx and have a nice weekend


show ip route
show ipv6 route
show ipv6 neighbors
show interfaces

sudo ip addr list