For DNS requests that I send to 2001:470:20::2 through the tunnel server on 216.66.80.30 it frequently takes a minute before I get an answer back. Other traffic through the tunnel works just fine, so I guess the problem is with the DNS server or the connection between the tunnel server and the DNS server.
Is there anything else I can do to debug the problem?
This is still an issue. It might only be a problem on tserv6.fra1. I tested with tserv23.zrh1 as well, and through that tunnel server I had no problems.
kasperd@dell-desktop:~$ time dig +time=999 google.com @2001:470:20::2
; <<>> DiG 9.6.1-P2 <<>> +time=999 google.com @2001:470:20::2
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58173
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;google.com. IN A
;; ANSWER SECTION:
google.com. 167 IN A 209.85.149.147
google.com. 167 IN A 209.85.149.104
google.com. 167 IN A 209.85.149.105
google.com. 167 IN A 209.85.149.99
google.com. 167 IN A 209.85.149.106
google.com. 167 IN A 209.85.149.103
;; Query time: 411763 msec
;; SERVER: 2001:470:20::2#53(2001:470:20::2)
;; WHEN: Thu Jun 9 10:04:22 2011
;; MSG SIZE rcvd: 124
real 6m51.781s
user 0m0.000s
sys 0m0.008s
kasperd@dell-desktop:~$
Seems the situation has gotten worse, so I changed my configuration to use 2001:470:0:11d::2 instead of the anycast address. A 23 minute latency on a DNS lookup is a bit extreme.
time dig +time=999 google.com @2001:470:20::2
; <<>> DiG 9.6.1-P2 <<>> +time=999 google.com @2001:470:20::2
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34422
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;google.com. IN A
;; ANSWER SECTION:
google.com. 185 IN A 209.85.149.147
google.com. 185 IN A 209.85.149.103
google.com. 185 IN A 209.85.149.104
google.com. 185 IN A 209.85.149.99
google.com. 185 IN A 209.85.149.105
google.com. 185 IN A 209.85.149.106
;; Query time: 384336 msec
;; SERVER: 2001:470:20::2#53(2001:470:20::2)
;; WHEN: Thu Jun 9 13:14:52 2011
;; MSG SIZE rcvd: 124
real 23m3.362s
user 0m0.012s
sys 0m0.004s