There are several people I’ve talked that say they have seen a drop in Network Packet Loss since upgrading from XenServer 6.2 to 6.5. Now, I’ve done some checking on my HW, and I have yet to see any packet loss. Running XS 6.5 SP1 all hotfixes since Sp1.

Here are some troubleshooting tips:

1. tcpdump to gather the trace.
2. check the latest driver available.
3. firmware of the nics, if latest available then , it will be good.
4. Disable IPV6, to see if there might be a mis config in your network around IPV6 support or not
5. If you can, change the network back-end to BRIDGE mode
6. take a dump on the xapi bridge ,PIF and some VIFS and check for any “tcp out-of-sequence” packets.
7. Turn off one of the NIC’s on the bond, if you have created one! It might actually be the network bond/teaming that is the issue!

There has been reports of people testing the Tech Preview of XenServer 7.0 (if that is the next number up from 6.5), that has seen that the issue has gone away!. Feel free to comment, if you have 1…