Is my 6to4 relay node Hurricane Electric?

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QUESTION :

I enabled 6to4. On bgp.he.net I see:


You are visiting from 2002:5aXX:XXXX:X:XXXX:XXXX:XXXX:XXXX

Announced as 2002::/16 (6to4)
Announced as 2002::/16 (6to4)
Announced as 2002::/16 (6to4)
Announced as 2002::/16 (6to4)
Announced as 2002::/16 (6to4)
Announced as 2002::/16 (6to4)
Announced as 2002::/16 (6to4)
Announced as 2002::/16 (6to4)

Your ISP is AS6939 (Hurricane Electric LLC)

Is Hurricane Electric my 6to4 relay node, or does bgp.he.net just pick the first from the possible AS numbers list?

Is there a way I can find the IP of my relay node?

ANSWER :

IP routing and especially 6to4 relaying is not necessarily symmetric – you might be sending packets through one relay node, but getting replies through another. Each sender will automatically use the relay that’s closest to them.

In other words, no matter what relay you use, HE’s systems will use their local 6to4 relay to respond to you, as the shortest path from HE’s systems to 2002::/16 is of course announced by AS6939.

If you run traceroute to 192.88.99.1, the second-to-last hop will usually reveal the ISP that’s hosting the relay that’s used for your outbound packets. (Unfortunately, the relay itself will usually just respond using its worldwide anycast address.)

You can also try running an IPv6 trace to 2002:: which will be recognized as “subnet router anycast” and will reveal the relay’s individual IPv6 address.

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