Hi, I'm not sure if the bridge code handles the packet checksum state correctly. I'm not even sure what the 'rules' for handling this field are. So it might be possible that there's a problem there.
cheers, Lennert On Tue, Dec 31, 2002 at 05:32:01PM +1030, Paul Schulz wrote: > Greetings, > Some more interesting results, see end of message for traffic dumps. > > > The interfaces are: > > BROADCOM Corporation NetXtreme BCM5703 > > With the IBM xSeries 305 acting as a bridge, I'm seeing TCP Checksum > errors after packets have passed through to bridge. > > ssh connection -> > > (host.229)--(bridge)--[Hub]--(host.230) > | > (tcpdump) > > Traffic dumps were obtained via a forth host connected via a hub, > using tcpdump and then analysed with Ethereal. Both with and without > the bridging host. > > dump-with.txt: > ------------- > Transmission Control Protocol, Src Port: 32795 (32795), Dst Port: ssh > (22), Seq: 2575813423, Ack: 0, Len: 0 > Source port: 32795 (32795) > Destination port: ssh (22) > Sequence number: 2575813423 > Header length: 40 bytes > Checksum: 0x16fd (incorrect, should be 0x3b27) > > dump-without.txt: > ----------------- > Transmission Control Protocol, Src Port: ssh (22), Dst Port: 32797 > (32797), Seq: 289612427, Ack: 4286922994, Len: 0 > Source port: ssh (22) > Destination port: 32797 (32797) > Sequence number: 289612427 > Acknowledgement number: 4286922994 > Header length: 40 bytes > Checksum: 0xf71e (correct) > > (There was no checksum error observed on packets as they entered the > bridge.) > > This look like a driver issue. The next step is to see if the > Broadcom driver has the same (or different issues). > > Paul > -- > Paul Schulz - Software Engineer [codito, ergo sum] > Foursticks Pty Ltd - 2/259 Glen Osmond Road, Frewville, SA 5063 > Phone: +61 8 8338 5500 Fax: +61 8 8338 5511 Mobile: +61 401 981 > 301 > Email: [EMAIL PROTECTED] Web: www.foursticks.com > > > > To: [EMAIL PROTECTED] > > Cc: [EMAIL PROTECTED] > > > > Greetings, > > > > I'm having an interesting problem with using bridging under 2.4.20, on > > an IBM xSeries 305, using the onboard network interfaces (see below) > > > > I can ping through the bridge (ICMP), but IP packets don't seem to get > > through from other hosts. (eg ssh, and web connections don't > complete.) > > > > eth0: Tigon3 [partno(BCM95703A30) rev 1002 PHY(5703)] > > (PCIX:100MHz:64-bit) 10/100/1000BaseT > > (eth1 is similar) > > > > The driver being used is: tg3 (from the default 2.4.20 kernel). > > > > Has anyone else used bridging with this chipset with success? > > > > Paul > > -- > > > ---(dump-with.txt)----------------------------------------------------- > Frame 17 (74 on wire, 74 captured) > Arrival Time: Dec 31, 2002 23:15:18.775372000 > Time delta from previous packet: 0.899669000 seconds > Time relative to first packet: 16.903629000 seconds > Frame Number: 17 > Packet Length: 74 bytes > Capture Length: 74 bytes > Ethernet II > Destination: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Source: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.229 (10.130.0.229), Dst Addr: > 10.130.0.230 (10.130.0.230) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 60 > Identification: 0x2291 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0x015d (correct) > Source: 10.130.0.229 (10.130.0.229) > Destination: 10.130.0.230 (10.130.0.230) > Transmission Control Protocol, Src Port: 32795 (32795), Dst Port: ssh > (22), Seq: 2575813423, Ack: 0, Len: 0 > Source port: 32795 (32795) > Destination port: ssh (22) > Sequence number: 2575813423 > Header length: 40 bytes > Flags: 0x0002 (SYN) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...0 .... = Acknowledgment: Not set > .... 0... = Push: Not set > .... .0.. = Reset: Not set > .... ..1. = Syn: Set > .... ...0 = Fin: Not set > Window size: 5840 > Checksum: 0x16fd (incorrect, should be 0x3b27) > Options: (20 bytes) > Maximum segment size: 1460 bytes > SACK permitted > Time stamp: tsval 81917303, tsecr 0 > NOP > Window scale: 0 bytes > > Frame 19 (210 on wire, 96 captured) > Arrival Time: Dec 31, 2002 23:15:20.137351000 > Time delta from previous packet: 0.260486000 seconds > Time relative to first packet: 18.265608000 seconds > Frame Number: 19 > Packet Length: 210 bytes > Capture Length: 96 bytes > Ethernet II > Destination: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Source: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.229 (10.130.0.229), Dst Addr: > 10.130.0.230 (10.130.0.230) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 196 > Identification: 0xe5a0 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0x3dc5 (correct) > Source: 10.130.0.229 (10.130.0.229) > Destination: 10.130.0.230 (10.130.0.230) > Transmission Control Protocol, Src Port: 32794 (32794), Dst Port: ssh > (22), Seq: 630714440, Ack: 945215028, Len: 144 > Source port: 32794 (32794) > Destination port: ssh (22) > Sequence number: 630714440 > Next sequence number: 630714584 > Acknowledgement number: 945215028 > Header length: 32 bytes > Flags: 0x0019 (FIN, PSH, ACK) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...1 .... = Acknowledgment: Set > .... 1... = Push: Set > .... .0.. = Reset: Not set > .... ..0. = Syn: Not set > .... ...1 = Fin: Set > Window size: 8832 > Checksum: 0x1785 > Options: (12 bytes) > NOP > NOP > Time stamp: tsval 81918665, tsecr 82640260 > Data (30 bytes) > > 0000 f4 0f eb 20 02 00 21 e8 57 92 86 d8 28 94 0e df ... ..!.W...(... > 0010 26 92 dc 7f 0c c6 79 8b 45 c9 5d 50 86 23 &.....y.E.]P.# > > Frame 22 (74 on wire, 74 captured) > Arrival Time: Dec 31, 2002 23:15:24.785203000 > Time delta from previous packet: 0.908235000 seconds > Time relative to first packet: 22.913460000 seconds > Frame Number: 22 > Packet Length: 74 bytes > Capture Length: 74 bytes > Ethernet II > Destination: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Source: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.229 (10.130.0.229), Dst Addr: > 10.130.0.230 (10.130.0.230) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 60 > Identification: 0x2292 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0x015c (correct) > Source: 10.130.0.229 (10.130.0.229) > Destination: 10.130.0.230 (10.130.0.230) > Transmission Control Protocol, Src Port: 32795 (32795), Dst Port: ssh > (22), Seq: 2575813423, Ack: 0, Len: 0 > Source port: 32795 (32795) > Destination port: ssh (22) > Sequence number: 2575813423 > Header length: 40 bytes > Flags: 0x0002 (SYN) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...0 .... = Acknowledgment: Not set > .... 0... = Push: Not set > .... .0.. = Reset: Not set > .... ..1. = Syn: Set > .... ...0 = Fin: Not set > Window size: 5840 > Checksum: 0x16fd (incorrect, should be 0x23b7) > Options: (20 bytes) > Maximum segment size: 1460 bytes > SACK permitted > Time stamp: tsval 81923303, tsecr 0 > NOP > Window scale: 0 bytes > > ---(dump-without.txt)-------------------------------------------------- > Frame 12 (74 on wire, 74 captured) > Arrival Time: Dec 31, 2002 23:42:17.476332000 > Time delta from previous packet: 0.000142000 seconds > Time relative to first packet: 11.274635000 seconds > Frame Number: 12 > Packet Length: 74 bytes > Capture Length: 74 bytes > Ethernet II > Destination: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Source: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.230 (10.130.0.230), Dst Addr: > 10.130.0.229 (10.130.0.229) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 60 > Identification: 0x0000 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0x23ee (correct) > Source: 10.130.0.230 (10.130.0.230) > Destination: 10.130.0.229 (10.130.0.229) > Transmission Control Protocol, Src Port: ssh (22), Dst Port: 32797 > (32797), Seq: 289612427, Ack: 4286922994, Len: 0 > Source port: ssh (22) > Destination port: 32797 (32797) > Sequence number: 289612427 > Acknowledgement number: 4286922994 > Header length: 40 bytes > Flags: 0x0012 (SYN, ACK) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...1 .... = Acknowledgment: Set > .... 0... = Push: Not set > .... .0.. = Reset: Not set > .... ..1. = Syn: Set > .... ...0 = Fin: Not set > Window size: 5792 > Checksum: 0xf71e (correct) > Options: (20 bytes) > Maximum segment size: 1460 bytes > SACK permitted > Time stamp: tsval 89550751, tsecr 83539200 > NOP > Window scale: 0 bytes > > Frame 13 (66 on wire, 66 captured) > Arrival Time: Dec 31, 2002 23:42:17.476437000 > Time delta from previous packet: 0.000105000 seconds > Time relative to first packet: 11.274740000 seconds > Frame Number: 13 > Packet Length: 66 bytes > Capture Length: 66 bytes > Ethernet II > Destination: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Source: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.229 (10.130.0.229), Dst Addr: > 10.130.0.230 (10.130.0.230) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 52 > Identification: 0xf5f2 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0x2e03 (correct) > Source: 10.130.0.229 (10.130.0.229) > Destination: 10.130.0.230 (10.130.0.230) > Transmission Control Protocol, Src Port: 32797 (32797), Dst Port: ssh > (22), Seq: 4286922994, Ack: 289612428, Len: 0 > Source port: 32797 (32797) > Destination port: ssh (22) > Sequence number: 4286922994 > Acknowledgement number: 289612428 > Header length: 32 bytes > Flags: 0x0010 (ACK) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...1 .... = Acknowledgment: Set > .... 0... = Push: Not set > .... .0.. = Reset: Not set > .... ..0. = Syn: Not set > .... ...0 = Fin: Not set > Window size: 5840 > Checksum: 0x25b4 (correct) > Options: (12 bytes) > NOP > NOP > Time stamp: tsval 83539200, tsecr 89550751 > > Frame 14 (105 on wire, 96 captured) > Arrival Time: Dec 31, 2002 23:42:17.477467000 > Time delta from previous packet: 0.001030000 seconds > Time relative to first packet: 11.275770000 seconds > Frame Number: 14 > Packet Length: 105 bytes > Capture Length: 96 bytes > Ethernet II > Destination: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Source: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.230 (10.130.0.230), Dst Addr: > 10.130.0.229 (10.130.0.229) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 91 > Identification: 0x4d13 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0xd6bb (correct) > Source: 10.130.0.230 (10.130.0.230) > Destination: 10.130.0.229 (10.130.0.229) > Transmission Control Protocol, Src Port: ssh (22), Dst Port: 32797 > (32797), Seq: 289612428, Ack: 4286922994, Len: 39 > Source port: ssh (22) > Destination port: 32797 (32797) > Sequence number: 289612428 > Next sequence number: 289612467 > Acknowledgement number: 4286922994 > Header length: 32 bytes > Flags: 0x0018 (PSH, ACK) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...1 .... = Acknowledgment: Set > .... 1... = Push: Set > .... .0.. = Reset: Not set > .... ..0. = Syn: Not set > .... ...0 = Fin: Not set > Window size: 5792 > Checksum: 0x0650 > Options: (12 bytes) > NOP > NOP > Time stamp: tsval 89550752, tsecr 83539200 > Data (30 bytes) > > 0000 53 53 48 2d 32 2e 30 2d 4f 70 65 6e 53 53 48 5f SSH-2.0-OpenSSH_ > 0010 33 2e 34 70 31 20 44 65 62 69 61 6e 20 31 3.4p1 Debian 1 > > Frame 15 (66 on wire, 66 captured) > Arrival Time: Dec 31, 2002 23:42:17.477613000 > Time delta from previous packet: 0.000146000 seconds > Time relative to first packet: 11.275916000 seconds > Frame Number: 15 > Packet Length: 66 bytes > Capture Length: 66 bytes > Ethernet II > Destination: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Source: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.229 (10.130.0.229), Dst Addr: > 10.130.0.230 (10.130.0.230) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 52 > Identification: 0xf5f3 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0x2e02 (correct) > Source: 10.130.0.229 (10.130.0.229) > Destination: 10.130.0.230 (10.130.0.230) > Transmission Control Protocol, Src Port: 32797 (32797), Dst Port: ssh > (22), Seq: 4286922994, Ack: 289612467, Len: 0 > Source port: 32797 (32797) > Destination port: ssh (22) > Sequence number: 4286922994 > Acknowledgement number: 289612467 > Header length: 32 bytes > Flags: 0x0010 (ACK) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...1 .... = Acknowledgment: Set > .... 0... = Push: Not set > .... .0.. = Reset: Not set > .... ..0. = Syn: Not set > .... ...0 = Fin: Not set > Window size: 5840 > Checksum: 0x258b (correct) > Options: (12 bytes) > NOP > NOP > Time stamp: tsval 83539201, tsecr 89550752 > > Frame 16 (105 on wire, 96 captured) > Arrival Time: Dec 31, 2002 23:42:17.477794000 > Time delta from previous packet: 0.000181000 seconds > Time relative to first packet: 11.276097000 seconds > Frame Number: 16 > Packet Length: 105 bytes > Capture Length: 96 bytes > Ethernet II > Destination: 00:02:55:b7:27:f9 (IBM_b7:27:f9) > Source: 00:02:55:b7:27:e1 (IBM_b7:27:e1) > Type: IP (0x0800) > Internet Protocol, Src Addr: 10.130.0.229 (10.130.0.229), Dst Addr: > 10.130.0.230 (10.130.0.230) > Version: 4 > Header length: 20 bytes > Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) > 0000 00.. = Differentiated Services Codepoint: Default (0x00) > .... ..0. = ECN-Capable Transport (ECT): 0 > .... ...0 = ECN-CE: 0 > Total Length: 91 > Identification: 0xf5f4 > Flags: 0x04 > .1.. = Don't fragment: Set > ..0. = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: TCP (0x06) > Header checksum: 0x2dda (correct) > Source: 10.130.0.229 (10.130.0.229) > Destination: 10.130.0.230 (10.130.0.230) > Transmission Control Protocol, Src Port: 32797 (32797), Dst Port: ssh > (22), Seq: 4286922994, Ack: 289612467, Len: 39 > Source port: 32797 (32797) > Destination port: ssh (22) > Sequence number: 4286922994 > Next sequence number: 4286923033 > Acknowledgement number: 289612467 > Header length: 32 bytes > Flags: 0x0018 (PSH, ACK) > 0... .... = Congestion Window Reduced (CWR): Not set > .0.. .... = ECN-Echo: Not set > ..0. .... = Urgent: Not set > ...1 .... = Acknowledgment: Set > .... 1... = Push: Set > .... .0.. = Reset: Not set > .... ..0. = Syn: Not set > .... ...0 = Fin: Not set > Window size: 5840 > Checksum: 0x05f8 > Options: (12 bytes) > NOP > NOP > Time stamp: tsval 83539201, tsecr 89550752 > Data (30 bytes) > > 0000 53 53 48 2d 32 2e 30 2d 4f 70 65 6e 53 53 48 5f SSH-2.0-OpenSSH_ > 0010 33 2e 34 70 31 20 44 65 62 69 61 6e 20 31 3.4p1 Debian 1 > > ----------------------------------------------------------------------- > > -- > Paul Schulz - Software Engineer [codito, ergo sum] > Foursticks Pty Ltd - 2/259 Glen Osmond Road, Frewville, SA 5063 > Phone: +61 8 8338 5500 Fax: +61 8 8338 5511 Mobile: +61 401 981 > 301 > Email: [EMAIL PROTECTED] Web: www.foursticks.com > > _______________________________________________ > Bridge mailing list > [EMAIL PROTECTED] > http://www.math.leidenuniv.nl/mailman/listinfo/bridge _______________________________________________ Bridge mailing list [EMAIL PROTECTED] http://www.math.leidenuniv.nl/mailman/listinfo/bridge
