Steven Stern <subscribed-lists@xxxxxxxxxxxxx> wrote: >>Kernel 2.6.7 uses different network parameters than kernel 2.6.6. >>For example, window scaling is turned on in 2.6.7 (but it was off >>on 2.6.6). This causes problems with most firewalls. Execute the >>following command with root privileges, that should "fix" the >>networking problem for all new connections: >> >> sysctl -w net.ipv4.tcp_default_win_scale=0 > > Does this apply to relatively dumb switches, too? Usually not. ;-) > I'm seeing tremendous slowdowns with 2.6.7. You might want to try the following changes as well (as they were the default in kernel 2.6.6): sysctl -w net.ipv4.tcp_moderate_rcvbuf=0 sysctl -w net.ipv4.tcp_bic=0 However, it looks like there were a lot more networking-related changes from 2.6.6 to 2.6.7. After disabling window scaling, I got back my full bandwidth, but interactive sessions (like remote shell) are still a little bit bumpy. While IPV4 basically now works for me, IPV6 is still catastrophic. But I haven't found a work-around for that problem yet (kernel options for IPV6 seem to be the same between 2.6.6 and 2.6.7, but the ChangeLog lists a couple of IPV6-related changes). Disabling IPV6 is not an option for me, so I'm still trying to find out what's different with IPV6 in 2.6.6 and 2.6.7. Sometimes I have the feeling that Fedore Core 2 doesn't use the original kernel 2.6.7 but applied some very strange patches. Greetings, Andreas
