On Fri, 13 May 2011 14:38:34 -0700 Chuck Swiger wrote: CS> On May 13, 2011, at 1:07 PM, Ivan Voras wrote: >> I'm seeing an an unusual problem at a remote machine; this machine is >> the FreeBSD server, and the client is a probably Windows machine (but I >> don't know the details yet). Something happens which causes FreeBSD to >> send ACKs to the client, and the client to send ICMP unreachable >> messages to the server. It is most likely a configuration error at the >> remote site but I have no idea how to verify this.
CS> Let's look at just one connection: CS> 18:56:02.711942 IP server.http > client.4732: Flags [.], ack 2110905191, win 0, length 0 CS> 18:56:02.713155 IP server.http > client.4732: Flags [.], ack 1, win 65535, length 0 CS> The packet is FreeBSD webserver sending ACKs with zero window size; CS> that's a sign of congestion that the client should not be sending more CS> data and instead doing periodic window probes until the local box opens CS> the window again. The next packet on the same connection then ACK's CS> something outside of the window with a 64K window size. That's wrong; CS> the other side probably sends an RST and the ICMP error. If you have TSO CS> enabled, try turning it off. Might be this the thing that jhb@ was fixing in r221346? -- Mikolaj Golub _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
