jamesmacwhite
Casual Member
So I'm sure there are many people aware of the IPv6 mega thread over on the Virgin Media community forums that's been on-going for over 10 years now about the lack of IPv6. Well more recently lukegb on Twitter found out that there is in fact a live IPv6 network hiding in plain sight and it's usable. Sort of.
A while ago, I accidentally discovered part of this by seeing Router Advertisements for IPv6 prefixes on the WAN side. I was tipped off when I changed a Linux kernel parameter called accept_ra on my network interfaces to 2 and suddenly two IPv6 routes from Virgin Media showed up in the routing table.
I dug into it a bit more and found these can be revealed by using tcpdump on the WAN interface, example:
This will poll my Virgin Media WAN interface for ICMP6 traffic specifically for Router Advertisement packets, surprise, these RA messages are present:
There are two notable prefixes in the RA:
Luke when one step further than I did and essentially assigning yourself a suitable address within this prefix, you can get working IPv6, which Luke shows from test-ipv6.com:
The prefix differs based on customer/area ref I believe.
Obviously, this isn't actually live and I don't think VM engineers expect anyone to be messing with this, but it at least confirms there's certainly a working IPv6 network there. This is present on both residential and business lines. With the talks around DS-Lite and such, it's interesting that this is essentially dual-stack.
While the Router Advertisements have the managed flag, DHCPv6 traffic seems to be filtered, so no prefix delegation, hence manually having to assign a IPv6 address to actually test it. It has also been noted not everyone seems to be able to see these Router Advertisements. I have only be able to verify them using a Linux based OS/Router, I've seen others say they can't see them. Equally, unless you are using your own kit, I doubt you'll be able to ever see the RA packets on the Hubs as they are locked down and will be ignoring them.
Virgin Media to launch IPv6 in 2021 anyone?!
A while ago, I accidentally discovered part of this by seeing Router Advertisements for IPv6 prefixes on the WAN side. I was tipped off when I changed a Linux kernel parameter called accept_ra on my network interfaces to 2 and suddenly two IPv6 routes from Virgin Media showed up in the routing table.
I dug into it a bit more and found these can be revealed by using tcpdump on the WAN interface, example:
Bash:
tcpdump -vvvv -ttt -i eth1.2 icmp6 and 'ip6[40] = 134'
This will poll my Virgin Media WAN interface for ICMP6 traffic specifically for Router Advertisement packets, surprise, these RA messages are present:
Code:
tcpdump: listening on eth1.2, link-type EN10MB (Ethernet), capture size 262144 bytes
00:00:00.000000 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 80) fe80::201:5cff:fe9c:2847 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 80
hop limit 0, Flags [managed, other stateful], pref medium, router lifetime 9000s, reachable time 3600000ms, retrans timer 0ms
prefix info option (3), length 32 (4): 2a02:8800:f000:18b0::/64, Flags [onlink], valid time 2592000s, pref. time 604800s
0x0000: 4080 0027 8d00 0009 3a80 0000 0000 2a02
0x0010: 8800 f000 18b0 0000 0000 0000 0000
prefix info option (3), length 32 (4): 2a02:88fd:18:a::/64, Flags [onlink], valid time infinity, pref. time infinity
0x0000: 4080 ffff ffff ffff ffff 0000 0000 2a02
0x0010: 88fd 0018 000a 0000 0000 0000 0000
There are two notable prefixes in the RA:
- 2a02:8800:f000:18b0::/64
- 2a02:88fd:18:a::/64
Luke when one step further than I did and essentially assigning yourself a suitable address within this prefix, you can get working IPv6, which Luke shows from test-ipv6.com:
The prefix differs based on customer/area ref I believe.
Obviously, this isn't actually live and I don't think VM engineers expect anyone to be messing with this, but it at least confirms there's certainly a working IPv6 network there. This is present on both residential and business lines. With the talks around DS-Lite and such, it's interesting that this is essentially dual-stack.
While the Router Advertisements have the managed flag, DHCPv6 traffic seems to be filtered, so no prefix delegation, hence manually having to assign a IPv6 address to actually test it. It has also been noted not everyone seems to be able to see these Router Advertisements. I have only be able to verify them using a Linux based OS/Router, I've seen others say they can't see them. Equally, unless you are using your own kit, I doubt you'll be able to ever see the RA packets on the Hubs as they are locked down and will be ignoring them.
Virgin Media to launch IPv6 in 2021 anyone?!