We have been seeing lots of duplicate packets on many VM's lately. I can only assume they have been happening for a long time but just recently became an issue. I found an article saying to disable the offload feature on the VMXNET3 NIC via the guest OS to help fix these issues. We tested it on a couple Windows Server 2008 R2 boxes and it did clear up.
Does anyone know any reason not to set these to disabled?
IPv4 Checksum Offload
IPv4 TSO Offload
Large Send Offload V2 (IPv4)
Large Send Offload V2 (IPv6)
Offload IP Options
Offload TCP Options
TCP Checksum Offload (IPv4)
TCP Checksum Offload (IPv6)
UDP Checksum Offload (IPv4)
UDP Checksum Offload (IPv6)
We are going to be doing testing on 2003 and 2008 servers to see if they have this issue before I make the changes to our templates and every single VM... I guess this is going to be a long manual process...