On 11/30/2011 02:06 AM, Amos Jeffries wrote:
Data packet from Squid->Server. 1085 bytes. Well under both 1160 and 1460 sizes, even with TCP packet bits added. However the packet checksum is incorrect. This is a problem in the kernel code somewhere. Given that it works on the same box with older Squid it is likely something to do with the IPv4/IPpv6 v4-mapping features of the kernel. Squid-3.1 prefers to use "v4-mapped" IPv6 sockets and let the kernel swap the TCP stacks around depending on the IP address type connected to.
I'm not entirely sure what you said here, but I tried to pursue the issue further based on this having to do something with the kernel and perhaps IPv6. On the old squid2 server, running debian etch, we have linux 2.6.18-6-686. To make sure, I installed squid 2.7.STABLE9-2.1 on the squid3 server, changed the http_port, to be able to run both at the same time, and verified that we could indeed access www.usitc.gov from the same host running a 2.x version of squid. After that I have tried both changing linux from 2.6.32-5-amd64 (from debian stable) to 2.6.38-bpo.2-amd64 (from squeeze-backports) as well as completely disable IPv6 on the host. We don't use IPv6 and have no IPv6 connections to the outside world, but the interfaces did, of course, have link-local addresses, however, disabling IPv6 did not make any difference to the state of not being able to access the site. Is there any other information I could provide you with? To my knowlege, this is the only site we are having these problems with. -- Fredrik
