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