Hi,
I have been analysing my network traffic and i noticed that all my tcp packets have an incorrect checksum..
here is an example packet.
0000 00 d0 52 0b 36 20 00 11 09 28 c5 e0 08 00 45 00 ..R.6 .. .(....E.
0010 00 28 a6 dc 40 00 80 06 8c c4 55 e0 c6 0f d4 cc .(..@... ..U.....
0020 d6 72 0c 31 1a 0b 34 41 62 a0 93 d2 49 77 50 10 .r.1..4A b...IwP.
0030 ff 24 c7 49 00 00 .$.I..
the checksum c7 49 should actually be 4f 19 according to ethereal...
i have checksum offload set to enabled and driver 4.4.2.0 17/05/2004
this happens with every TCP packet.. either ethereal is wrong or the driver is doing something bad.
this error actually does lead to retransmission sometimes.
I turned off CRC offload and no more constant CRC failures, i guess that the NIC hardware doesnt calculate the CRC correctly OOOPS!
my network seems alot more happy when the crcs are correct, so i suggest that you all check this
you can log your traffic by installing ethereal
the software overhead of calculating CRC32 is minimal so i would suggest to all to turn off CRC offload.
www.ethereal.com
I have been analysing my network traffic and i noticed that all my tcp packets have an incorrect checksum..
here is an example packet.
0000 00 d0 52 0b 36 20 00 11 09 28 c5 e0 08 00 45 00 ..R.6 .. .(....E.
0010 00 28 a6 dc 40 00 80 06 8c c4 55 e0 c6 0f d4 cc .(..@... ..U.....
0020 d6 72 0c 31 1a 0b 34 41 62 a0 93 d2 49 77 50 10 .r.1..4A b...IwP.
0030 ff 24 c7 49 00 00 .$.I..
the checksum c7 49 should actually be 4f 19 according to ethereal...
i have checksum offload set to enabled and driver 4.4.2.0 17/05/2004
this happens with every TCP packet.. either ethereal is wrong or the driver is doing something bad.
this error actually does lead to retransmission sometimes.
I turned off CRC offload and no more constant CRC failures, i guess that the NIC hardware doesnt calculate the CRC correctly OOOPS!
my network seems alot more happy when the crcs are correct, so i suggest that you all check this
you can log your traffic by installing ethereal
the software overhead of calculating CRC32 is minimal so i would suggest to all to turn off CRC offload.
www.ethereal.com
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