Date: Fri, 7 Mar 2008 22:55:56 +0000 From: "Jake Rizzo" <rizzojake@gmail.com> To: freebsd-net@freebsd.org Subject: RELENG-7 tcp connectivity problems with certain clients Message-ID: <b07c271a0803071455q4c44b626hf93ccad27ffed5ec@mail.gmail.com>
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Hi, I had two 6.3-STABLE boxen which have been happily running away for months on end now without any problems. Last week I upgraded (via buildworld) both boxes to 7.0-STABLE. Since then I've had reports of some clients being unable to connect via tcp. I've seen this happen first hand on an affected remote machine. Traceroute & ping gets to the machine just fine but connecting to an open tcp port on the machine just times out. The remote box was a XP machine and so I didn't have the luxury of tcp dump on that end, however I did get a chance to run it at the freebsd end: 16:04:31.445390 IP (tos 0x20, ttl 109, id 41184, offset 0, flags [DF], proto TCP (6), length 48) xxxxx.comcastbusiness.net.22625 > 192.168.1.104.http: S, cksum 0x81e2 (correct), 3539746141:3539746141(0) win 16384 <mss 1380,nop,nop,sackOK> 16:04:31.445405 IP (tos 0x0, ttl 64, id 55077, offset 0, flags [DF], proto TCP (6), length 48, bad cksum 0 (->b21)!) 192.168.1.104.http > xxxxx.comcastbusiness.net.22625: S, cksum 0x58a4 (incorrect (-> 0x8f6e), 152644170:152644170(0) ack 3539746142 win 65535 <mss 1380,sackOK,eol> 16:04:34.444871 IP (tos 0x0, ttl 64, id 56095, offset 0, flags [DF], proto TCP (6), length 48, bad cksum 0 (->727)!) 192.168.1.104.http > xxxxx.comcastbusiness.net.22625: S, cksum 0x58a4 (incorrect (-> 0x8f6e), 152644170:152644170(0) ack 3539746142 win 65535 <mss 1380,sackOK,eol> 16:04:40.444521 IP (tos 0x0, ttl 64, id 57587, offset 0, flags [DF], proto TCP (6), length 48, bad cksum 0 (->153)!) 192.168.1.104.http > xxxxx.comcastbusiness.net.22625: S, cksum 0x58a4 (incorrect (-> 0x8f6e), 152644170:152644170(0) ack 3539746142 win 65535 <mss 1380,sackOK,eol> It seems the the tcp handshake is not happening for one reason or another. I downgraded one of the boxes back to 6.3-STABLE and now the same client's connectivity issues disappeared. Has anyone any ideas of where to look? I'd really like to stay on 7.0-STABLE if I can because of the performance increase! Here's some additional configuration details: Ifconfig output: bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM> ether 00:e0:81:33:48:f6 inet 192.168.1.197 netmask 0xffffff00 broadcast 192.168.1.255 inet 192.168.1.104 netmask 0xffffffff broadcast 192.168.1.104 media: Ethernet autoselect (100baseTX <full-duplex>) status: active dmesg| grep bge0: bge0: <Broadcom Gigabit Ethernet Controller, ASIC rev. 0x2003> mem 0xfc9c0000-0xfc9cffff,0xfc9b0000-0xfc9bffff irq 24 at device 9.0 on pci2 miibus0: <MII bus> on bge0 bge0: Ethernet address: 00:e0:81:33:48:f6 bge0: [ITHREAD] I have a few network related sysctl's defined since 6.3-STABLE too: security.bsd.see_other_uids=0 net.inet.icmp.icmplim=50 kern.ipc.somaxconn=12768 net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 net.inet.tcp.msl=7500 Any help would be greatly appreciated. Thanks, Regards, Jerry
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