I wrote: > >> If you can easily reproduce the issue, can you capture stalled TCP >> session with tcpdump on receiving host?(Make sure to disable Rx >> checksum offload prior to capturing the session.) > > I transferred a 256 kiB file and these are the tcpdumps: > > http://www.alpha-tierchen.de/~bkoenig/fxp0-with-tso.txt > http://www.alpha-tierchen.de/~bkoenig/fxp0-without-tso.txt > > Actually the transfer doesn't stall although ftp and scp told me so. It > becomes incredibly slow. It seems like that the chunks are too large and a > smaller packet will be resent. I decreased the MTU from 1500 to 1492 and > it works fine with TSO enabled. > > I also captured the traffic on my router: > > http://www.alpha-tierchen.de/~bkoenig/fxp0-with-tso-router.txt > http://www.alpha-tierchen.de/~bkoenig/fxp0-without-tso-router.txt > > It reveals a suspect information: "truncated-ip - 8 bytes missing!" > > I almost suppose that this is a PPPoE-related configuration issue and the > fxp driver is not necessarily the problem since decreasing the MTU of the > LAN host solves it.
Hello, it's me again. :) It's not PPPoE-related. I was able to reproduce the behaviour within a regular LAN from host to host. I also have another symptom which denies the PPPoE assumption: If I set MTU to value X then it doesn't work with MTU X+N anymore. I'll get the message "N bytes missing!" in the tcpdump output. For example: ifconfig fxp0 mtu 1448 # works ifconfig fxp0 mtu 1412 # still works ifconfig fxp0 mtu 1448 # doesn't work (36 bytes missing) ifconfig fxp0 mtu 1400 # works ifconfig fxp0 mtu 1412 # doesn't work (12 bytes missing) Regards Björn _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
