[Cialug] Inconsistent consistently long DNS lookup times

[Colin Burnett]

On Tue, Mar 9, 2010 at 9:40 PM, Colin Burnett <cmlburnett at gmail.com> wrote:
> What I've discovered thus far is that ping uses gethostbyname(3) and
> wget uses getaddrinfo(3).  I think it's tied to IPv6 lookup.  Doing a
> `wget --inet4-only http://www.google.com` yields immediate results
> then doing it without --inet4-only yields the 5 second delay (it's
> clearly not being cached).
>
> ifconfig shows ipv4 & ipv6 addresses.  Is there a way to disable ipv6
> support in gentoo without going through the whole recompiling the
> kernel without it?  Outright deleting the ipv6 addresses on eth0 & lo
> using ifconfig doesn't have the hoped/desired effect.

MOSTLY RESOLVED!

To disable IPv6 under gentoo I changed IPV6 to a module (from
compiled-in) in the kernel, recompiled and added:

alias net-pf-10 off
alias ipv6 off

in /etc/modules.d/aliases then rebooted.

This fixes Firefox and Seamonkey, but not wget nor ncftp nor my Python
script to Amazon.  Again using `wget --inet4-only` avoids the delay,
but I want something system-wide.

It would be nice to get everything lag-free but at least a fixed
Firefox removes the most annoying part of the lag.


Colin