On 24/01/2011, at 11:03 PM, Amos Jeffries wrote: > On 24/01/11 23:09, Michael Hendrie wrote: >> >> On 24/01/2011, at 8:17 PM, Saiful Alam wrote: >> <snip> >> >> I had issues with some random sites being "slow" with 3.1.10 and >> tracked it down to squid trying to get AAAA records for the problem >> sites (or objects pulled from other sites). Not sure why this was >> occurring as IPv6 is not enabled on the OS. I didn't investigate too >> much and just recompiled with --disable-ipv6 as it wasn't needed. >> Doing so resolved my slow sites issue. >> > > Seems like you actually had IPv6 partially enabled in the OS, and maybe a break in DNS or MTU. > > When Squid 3.1.10 starts up it probes the OS network capabilities to see > if IPv6 connections can be made. When they are possible it enables > things like AAAA to use those connections. --disable-ipv6 merely sets the result of that test to always be false. > > With a reasonably fast DNS response time (under a half second) AAAA lookups will not be noticeable. > > With working MTU there will be almost zero lag from opening and attempting IPv6 connections on an IPv4-only network. > Sorry to to hijack thread but thought I'd post my findings on this as it may be useful to other users. Thanks to Amos for comments, investigation shows that simply telling RHEL/CENTOS (5.5) not to enable IPv6 with NETWORKING_IPV6=no in /etc/sysconfig/network is not enough to disable IPv6. Article at http://www.cyberciti.biz/faq/redhat-centos-disable-ipv6-networking/ covers what is required. After doing this and recompiling squid this time without the --disable-ipv6 option, squid no longer issues AAAA lookup requests. <snip> > Amos > -- > Please be using > Current Stable Squid 2.7.STABLE9 or 3.1.10 > Beta testers wanted for 3.2.0.4
