On Wed, Feb 13, 2013 at 01:57:38PM -0800, Doug Hardie wrote: > > On 13 February 2013, at 02:29, Eugene Grosbein <egrosb...@rdtc.ru> wrote: > > > 13.02.2013 17:25, Doug Hardie ??????????: > >> Monitoring a tcpdump between two systems, a FreeBSD 9.1 system has the > >> following interface: > >> > >> msk0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 > >> > >> options=c011b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,TSO4,VLAN_HWTSO,LINKSTATE> > >> ether 00:11:2f:2a:c7:03 > >> inet 10.0.1.199 netmask 0xffffff00 broadcast 10.0.1.255 > >> inet6 fe80::211:2fff:fe2a:c703%msk0 prefixlen 64 scopeid 0x1 > >> nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL> > >> media: Ethernet autoselect (100baseTX > >> <full-duplex,flowcontrol,rxpause,txpause>) > >> status: active > >> > >> > >> It sent the following packet: (data content abbreviated) > >> > >> 02:14:42.081617 IP 10.0.1.199.443 > 10.0.1.2.61258: Flags [P.], seq > >> 930:4876, ack 846, win 1040, options [nop,nop,TS val 401838072 ecr > >> 920110183], length 3946 > >> 0x0000: 4500 0f9e ea89 4000 4006 2a08 0a00 01c7 E.....@.@.*..... > >> 0x0010: 0a00 0102 01bb ef4a ece1 680b ae37 1bbc .......J..h..7.. > >> 0x0020: 8018 0410 3407 0000 0101 080a 17f3 8ff8 ....4...??????. > >> > >> > >> The indicated packet length is 3946 and the load of data shown is that > >> size. The MTU on both interfaces is 1500. The receiving system received > >> 3 packets. There is a router and switch between them. One of them > >> fragmented that packet. This is part of a SSL/TLS exchange and one side or > >> the other is hanging on this and just dropping the connection. I suspect > >> the packet size is the issue. ssldump complains about the packet too and > >> stops monitoring. Could this possibly be related to the hardware > >> checksums? > > > > You have TSO enabled on the interface, so large outgoing TCP packet is > > pretty normal. > > It will be split by the NIC. Disable TSO with ifconfig if it interferes > > with your ssldump. > > Thanks. Now all the packets are 1500 or under. They all are received with a > SSL header.
If disabling TSO on msk(4) fixed the issue of the remote end dropping/ignoring the packet, that sounds like a bug in msk(4). Yong-Hyeon, do you have any recent msk(4) patches relating to TSO? -- | Jeremy Chadwick j...@koitsu.org | | UNIX Systems Administrator http://jdc.koitsu.org/ | | Mountain View, CA, US | | Making life hard for others since 1977. PGP 4BD6C0CB | _______________________________________________ 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"
