[Bug 504963] [NEW] [Karmic] host -4 does IPv6 lookup -- times out

[Marcerino]

Public bug reported:

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 at 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 at 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://wiki.kartbuilding.net/index.php/DNS_-_Bind9#Slow_DNS_lookup_issues_with_bind9
http://ubuntuforums.org/showthread.php?t=87798
https://help.ubuntu.com/community/WebBrowsingSlowIPv6IPv4
http://www.ubuntugeek.com/how-to-disable-ipv6-in-ubuntu.html

** Affects: bind9 (Ubuntu)
     Importance: Undecided
         Status: New

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[Karmic] host -4 does IPv6 lookup -- times out
https://bugs.launchpad.net/bugs/504963
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