From the best I can tell, the driver should be computing the check sum (as stated previously).
I think that what we are seeing in Wireshark may be a false alarm. I was reading through the Wireshark wiki, and found the following FAQ:
http://www.wireshark.org/faq.html#q7.9
It basically says that frames with CRC errors won't even make it into the capture because they won't make it past the hardware; the NIC will drop all such frames.
And this make sense - bad frames are dropped at the hardware level. So, if these frames were truly bad frames, they wouldn't even make it into the OS, and therefore wouldn't even show up in Wireshark.
Furthermore, I have also tested on Linux and my Wireshark capture there shows all of the frames having CRC errors (with check sum == 0). But, when I look at the statistics in the OS, it shows that there are no error frames:
ULA0323418:~/temp/winapps> ifconfig
eth0 Link encap:Ethernet HWaddr d4:be:d9:3d:b9:0f
inet addr:192.168.1.117 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::d6be:d9ff:fe3d:b90f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:14190614 errors:0 dropped:0 overruns:0 frame:0
TX packets:14869449107 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1161074700 (1.1 GB) TX bytes:951662545307 (951.6 GB)
Interrupt:20 Memory:e2e00000-e2e20000
This indicates that the frames showing up in Wireshark as bad are actually not bad. If they were, they should have shown up in either the dropped, or error count statistics.
Hope this helps.
From the best I can tell, the driver should be computing the check sum (as stated previously).
I think that what we are seeing in Wireshark may be a false alarm. I was reading through the Wireshark wiki, and found the following FAQ:
http://www.wireshark.org/faq.html#q7.9
It basically says that frames with CRC errors won't even make it into the capture because they won't make it past the hardware; the NIC will drop all such frames.
And this make sense - bad frames are dropped at the hardware level. So, if these frames were truly bad frames, they wouldn't even make it into the OS, and therefore wouldn't even show up in Wireshark.
Furthermore, I have also tested on Linux and my Wireshark capture there shows all of the frames having CRC errors (with check sum == 0). But, when I look at the statistics in the OS, it shows that there are no error frames:
ULA0323418:~/temp/winapps> ifconfig
eth0 Link encap:Ethernet HWaddr d4:be:d9:3d:b9:0f
inet addr:192.168.1.117 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::d6be:d9ff:fe3d:b90f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:14190614 errors:0 dropped:0 overruns:0 frame:0
TX packets:14869449107 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1161074700 (1.1 GB) TX bytes:951662545307 (951.6 GB)
Interrupt:20 Memory:e2e00000-e2e20000
This indicates that the frames showing up in Wireshark as bad are actually not bad. If they were, they should have shown up in either the dropped, or error count statistics.
Hope this helps.
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