Mikael Abrahamsson wrote:
End users are using 6to4 and Teredo, if an ISP isn't providing their own
relays, someone else is and the performance might be good or bad.
Teredo usage isn't common enough on our network to warrant the work.
Very few apps will activate it is my guess.
Same logic applies to Teredo as to 6to4 and why if you're an ISP who
cares, you should run your own. Your customers are using both, whether
they know it or not.
A customer is more likely (not always) to know when teredo has been
activated. I've considered putting it in, but it is not friendly in many
ways. 6to4 is usually running on routers in various pops. Teredo, I'd
have to back feed to a server farm. This doesn't make for ideal traffic
patterns even with bandwidth being so low.
Then there is the "customer is unaware" fact. If the customer is unaware
that their NAT is being pierced for IPv6 communication, then we have
contributed to decreasing their security. For this reason, it might not
be completely unwarranted for an ISP to block teredo all together. 6to4
doesn't suffer from this as there is no NAT traversal.
Jack
