I have helped a few people recently who were having path MTU discovery problems, causing bulk TCP transfers to hang quasi-intermittently. Once you know the likely cause it's fairly easy but it's a fairly annoying problem for someone who doesn't recognize it.
There is a kernel sysctl "sudo sysctl -w net.ipv4.tcp_mtu_probing=1" that seems fairly effective at detecting when the problem is occurring and automatically fixing it. This implements RFC 4821. It is off by default in the kernel. I haven't seen any reports of problems caused by turning it on, but there may be some. I wonder if Ubuntu should turn it on in /etc/sysctl.d? -- Martin -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
