A couple of hours ago I was on a network where the only way I could get IPv6 access was by using a teredo client. I experienced 42% packet loss when trying to communicate between a teredo client and a server using a tunnelbroker.net tunnel.
The traffic was going through the tunnelserver on 216.66.80.90 and from the teredo client I saw the traffic going through a teredo relay on 216.66.84.182.
Traceroute between the two endpoints didn't work, so I couldn't pinpoint where the packet loss happened. Pinging the teredo relay on 216.66.84.182 from the teredo client "only" resulted in 16% packet loss.
With both the tunnelserver and teredo relay being operated by HE, I guess the problem is most likely in the HE network. Any suggestions what I can do to narrow down the root cause next time I am experiencing this problem?
Yes, send ping tests and complete traceroutes (or mtr output) from both sides showing the issue when you are experiencing it to ipv6@he.net.
Also make sure to do a test of general IPv6 connectivity using a known working site from both sides and include that as well. That ought to isolate the problem to one side or the other.
Haven't seen any email regarding this issue come into the ticket system, but I'll take a look at the Stockholm 6to4/teredo relay.
I'm only using teredo when I am on networks where I have no other options, so for the last few weeks I didn't notice if the problem was still there. Yesterday I was on that network again, and I noticed that the problem was still there. But I didn't have the necessary access set up to run traceroutes from both ends.
Today I disabled the usual IPv6 access from one of the machines using the tunnelbroker.net tunnel and configured it as a teredo client instead, such that I could do the full traceroutes from both ends. It made no difference to the outcome where the teredo client was located. I have send all the mtr output to ipv6@he.net.