I've just updated to the 2139 kernel and I'm encountering some network problems. Connections inside my department seem fine but connections to anywhere outside (other departments on campus, the rest of the world) lock up after some fairly small amount of traffic. The problems disappear if I reboot back into the 2133 kernel. The symptoms are very similar to some that I recall from a couple of years ago with the move to the 2.6.7 kernel where some of the networking parameters changed. At that time, there were problems with various firewalls/routers and the solution was to do sysctl -w net.ipv4.tcp_default_win_scale=0 sysctl -w net.ipv4.tcp_moderate_rcvbuf=0 (or the equivalent in /etc/sysctl.conf). tcp_default_win_scale doesn't seem to exist anymore, but setting tcp_window_scaling to 0 seems to work, at least as far as I've been able to check quickly. But I don't really understand what these parameters represent and don't want to mess things up. Can the gurus tell me what, in words of one syllable, what changed in this respect from the 2133 kernel to the 2139 and what the right fix is? What am I losing if I set tcp_window_scaling to 0? I have some influence on the settings of my department's network equipment, but the connection to the campus backbone is controlled by the Office of Information Technology, which generally doesn't respond well to requests from Linux users in the science and math departments. So if it's a question of me changing things on my Fedora boxes or OIT changing settings on its network equipment, I'll be the one making the changes. Thanks, George
