IPv6 tunnel on Paris server stopped working for me

[rgarcia]

Hi,

I am using a 6to4 tunnel since 2015 attached to Paris server. Last week it stopped working, I don't receive anymore any paquet from the tserv1.par2.he.net (216.66.84.42) server. My configuration has not changed. Is there any known issue with this endpoint?

traceroute trying to reach the server ipv6 address from the client (failure)

traceroute to 2001:470:1f12:4c2::1 (2001:470:1f12:4c2::1), 30 hops max, 80 byte packets
 1  * * *
 2  * * *
 3  * * *^C

traceroute trying to reach the server ipv6 address from the outside (success)
traceroute to 2001:470:1f12:4c2::1 (2001:470:1f12:4c2::1), 30 hops max, 80 byte packets
 1  2001:bc8:47b0:2203::  0.960 ms  0.852 ms  0.812 ms
 2  2001:bc8:407:304::1  1.371 ms  1.396 ms  1.363 ms
 3  2001:bc8:400:1::75  1.555 ms 2001:bc8:400:1::7d  1.465 ms 2001:bc8:400:1::75  1.567 ms
 4  2001:bc8:400:1::1b4  1.147 ms 2001:bc8:400:1::1b2  1.060 ms 2001:bc8:400:1::1a6  1.159 ms
 5  2001:bc8:400:100::c7  1.059 ms * *
 6  * * *
 7  2001:470:1f12:4c2::1  0.653 ms  0.833 ms  0.744 ms

Traceroute trying to reach the client ipv6 address from the outside (failure)
traceroute to 2001:470:1f12:4c2::2 (2001:470:1f12:4c2::2), 30 hops max, 80 byte packets
 1  2001:bc8:47b0:2203::  1.397 ms  1.312 ms  1.284 ms
 2  2001:bc8:407:304::1  1.354 ms  1.357 ms  1.313 ms
 3  2001:bc8:400:1::75  1.729 ms 2001:bc8:400:1::7d  1.673 ms 2001:bc8:400:1::75  1.730 ms
 4  2001:bc8:400:1::7c  1.916 ms 2001:bc8:400:1::1b6  1.906 ms 2001:bc8:400:1::1b8  1.407 ms
 5  2001:bc8:400:100::c7  1.419 ms 2001:bc8:400:100::c1  1.474 ms 2001:bc8:400:100::c7  1.751 ms
 6  * * *
 7  2001:470:0:7b::2  5.810 ms  5.434 ms  5.400 ms
 8  * * *
 9  * * *
10  * * *^C

Regards,
René

[rgarcia]

New test that confirms that outbound IPv6 trafic is correctly sent to target but answer does never come back : inbound paquets are lost somewhere as it seems there is a routing issue to go back to the 6to4 tunnel.
Is there anyone from HE reading this forum ?

[kcochran]

The forum is primary for community discussions.  Direct support questions should go to ipv6@he.net, since then we can discuss more specifics that people wouldn't want on the forum, such as their actual IPs.

That said, everything looks fine on the tunnel server.  I see traffic to you, and pings to your IPv4 work, but we see no IPv6 replies back from you.

[rgarcia]

OK, thank you for your reply. I will contact the support using their mail address. I can send packets outside (ping is sent and received by target). But I can't receive any answer (ping reply is sent but lost somewhere in the HE network according to traceroute). It has been working fine for years and it stopped working a few days ago.

[tomkep]

Traceroute goes as far as the tunnel server to which you are connected.

Do you have your IPv6 default route properly set?

[rgarcia]

All routes are correctly set. Everything was working fine before October 13th. I have made a new test today sending protocol 41 paquets to my client using nmap from a remote host outside my local network and I don't receive any of them. It seems that my ISP has changed something in its network and is now filtering incoming IP protocol 41. I have opened a ticket at my ISP support. Outgoing IP 41 is working as expected.