Re: strange TCP problem looks like PMTU but isn't

Russell Coker via luv-main writes:

I've got a Linux system running remotely that has a strange TCP problem, when it sends (not receives) a large packet the connection hangs. For example if I ssh in and run commands with small amounts of output everything is fine, but if I run "ls -l /" then the connection hangs forever.

I had a problem like that once where an ancient OpenBSD (or Solaris?) router was poorly configured. I was told to turn off window scaling on the Linux boxes behind it: sysctl net/ipv4/tcp_window_scaling=0 Eventually, I fixed it properly, by throwing away the broken router. Not sure if that's just broken PMTUD.