[coLinux-users] TCP Network Broken from Host to coLinux Broadcom WinPcap

[Miller, S. <sha...@yr...>]

Hello all,

 

Just for the record, I have a Broadcom NetLink Gigabit Ethernet NIC with
PCI IDs V14E4 (Broadcom, obviously), D1693.  My Windows XP driver is
b57xp32.sys.

 

I had encountered an issue where I could ping and perform any sort of
UDP to my hosted coLinux, but TCP wasn't working.  My coLinux' service
had parameters something like:

 

  --run-service coLinux kernel=vmlinux cobd0=c:\somepath\Ubuntu_2GB.ext3
root=/dev/cobd0 eth0=pcap-bridge,Wired,00:0c:29:ab:ad:7e,promisc

 

So I was obviously using WinPcap bridging.  I tried updating to the
latest WinPcap, but it didn't fix the problem.  Wireshark revealed a lot
of duplicate TCP ACKs and invalid checksums, so I checked the properties
for the Broadcom NIC.  In the Advanced tab of its properties, I had
Checksum Offload set to Tx/Rx TCP/IP Checksum.  I set it to None and the
problem disappeared and TCP communications now work as expected.  I had
not encountered this problem on some other hardware.

 

Just putting this out there as a solution, in case anyone can benefit.
Dunno if it's FAQ-worthy; possibly not.

 

- Shao Miller