Trying to get IPv6 to run along with modem in bridge mode.
With the modem in regular PPoE, DHCP, and NAT mode, Ipv4 works of course, and the modem gets a public IPv6 from the assigned range for the ISP. The Peplink gets an address that’s auto magically created from the public prefix, and devices on the LAN also get valid addresses. It all works.
Now put the modem into Bridge mode; The Peplink gets its DHCP IPv4 address ok, but nothing happens on the IPv6 side. I managed to grab the network capture of the Wan2 during its initial sign up, and the IPv6 parts are lacking.
Analysis of the packet dump, show the IPv6 Advertise/ Solicit (SLAAC) is present from the Wan2 Nic, but its directed at the adjacent NIC - the modem NIC, but the modem is not handing out an address or path to the wider net - it’s in bridge mode. The Peplink never calls a DHCPv6, so its a stalemate - no workable IPv6 address via SLAAC with a modem in bridge mode.
Seems like an oversight - DHCPv6 is required here - initiated by the Peplink, to get a workable IPv6 address.
Packet dump available on request.
Your systems work when your router (when a modem is doing PPoE, DHCP and NAT, it is a Router+modem) handles ipv6. The Peplink system does not actually route or do anything useful with ipv6. The ipv6 mode simply turns the peplink into a bridge for ipv6 traffic and it captures a SLAAC address itself. So only SLAAC is supported between WAN1 and LAN1… nothing else.
Also the peplink is now doing zero firewall work on IPv6, so you are completely open from a security point of view.
If you look at all of the other threads about the complete lack of real ipv6 support they say that something is coming in release 9.x… Of course we have been waiting for that for a couple of years.
I just run a PFsense firewall for IPv6 traffic only in parallel with the peplink. Of course this only works with one wired WAN and not the cellular systems.
Hi,
Thanks for the reply. But I will stay with my original thoughts. A modem in bridge mode, passes the Ethernet part between the two nodes its connect too i.e. the Peplink and the ISP’s line card in the DSLAM terminal. But SLAAC is link local to all connected nodes, i.e Peplink to the modem. The .pcap shows the modem gives a Router Ad msg straight off, but its Route Information msg is in the private space (fd3f:…). It can’t be anything else because the modem is offline for Ethernet in bridge mode.
IPv6 was designed with every node getting automatic addressing and discovery, and bridge mode excludes the modem from that method.
So I suspect that bridge mode and IPv6 are fundamentally incompatible.