[Karmic] host -4 does IPv6 lookup -- times out
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
bind9 (Ubuntu) |
Expired
|
Low
|
Unassigned |
Bug Description
Binary package hint: bind9
When using 'host' to do a dns lookup on Karmic, I get a fast initial response for the IPv4 lookup:
mvl@purple:~$ host www.google.com
www.google.com is an alias for www.l.google.com.
www.l.google.com has address 74.125.77.99
www.l.google.com has address 74.125.77.147
www.l.google.com has address 74.125.77.104
but then a long wait and a timeout on IPv6:
;; connection timed out; no servers could be reached
;; connection timed out; no servers could be reached
I guess this is because my home network router/DNS cache does not support IPv6. This timeout for host lookups with 'host' is not such a problem, but also seems to affect firefox (fixable with a setting) and ssh logins to remote machines. Why does the host command look for a IPv6 address after It gets a good IPv4 response?
I tried forcing only IPv4 lookup with 'host -4', but the result is the same:
mvl@purple:~$ host -4 www.google.com
www.google.com is an alias for www.l.google.com.
www.l.google.com has address 74.125.77.147
www.l.google.com has address 74.125.77.104
www.l.google.com has address 74.125.77.99
;; connection timed out; no servers could be reached
;; connection timed out; no servers could be reached
Is that behaviour intended? Is there really no way to gracefully ignore IPv6 when the local network does not support it? I am not the only one to run into this problem. See, for example:
http://
http://
https:/
http://
I some posts, I found that ip -6 route may provide useful info. Here is the output:
mvl@purple:~$ ip -6 r
fe80::/64 dev wlan0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 0
a friend of mine does not have the problem on the LTS version (8.04) of Ubuntu, and a different network. The output of the above on her machine is
fe80::/64 dev eth1 metric 256 expires 21330140sec mtu 1500 advmss 1440 hoplimit 4294967295
ff00::/8 dev eth1 metric 256 expires 21330140sec mtu 1500 advmss 1440 hoplimit 4294967295
Could it be that there is something wrong with the IPv6 kernel setup in Karmic/on my system?