Network problems with new kernel in Debian.
 

Hello!

Last updated kernel to 3.2.0-4-686-pae on my Debian firewall via apt-get. Previous kernel package was linux-image-3.2.0-4-686-pae_3.2.57-3+deb7u2_i386 and the last is linux-image-3.2.0-4-686-pae_3.2.60-1+deb7u1_i386.

After that, most of the sites was opened after long delays or not open at all.

No errors on the console. I do not know where to look for the problem.

Help, please.

Put the old kernel back in and see if that corrects it. I rather doubt it can be the kernel but you will have to test something. Use other route tests also. May need to try wireshark even.

I noticed the same issues when I updated to the security fixed (ptrace issue) kernel 3.2.60-1+deb7u1 (I was using the amd64 one though), when I returned to the 3.2.57-3+deb7u2 kernel my networking went fine. While I have not posted the bug myself on debian, it looks like it has been posted Bug#754173 (bugs.debian.org). Not much action yet. The problem with a kernel bug is it requires a reboot, and a lot of people need to schedule those for their servers, so you may not see a lot of people reporting the issue yet.

Thanks for reply. Looks like my case.

For those interested there is now some additional information under the debian bug report. It now links 2 bugs together. The current work around is to use ethtool to turn off the gro feature on your nic.

To make this survive booting, edit /etc/network/interfaces

Add a line:
pre-up /sbin/ethtool -K eth0 gro off

you will need 1 line per interface, and change eth0 to your correct nic.

It seems the bug is related to routing/nat.

I can confirm for my network configuration the work around seems to be working so far.

Thanks again. I already read about solution, upgrade the kernel and made changes in /etc/network/interfaces.