X11SPH-nCTF, Hyper-V vmSwitch and duplicated packets


Active Member
Dec 2, 2016
We have Hyper-V Server on which we created VMSwitch (with Switch Embedded Teaming) on two built in Intel x722 adapters.

On VMSwitch we have NetAdapter for Management OS with ip assigned (created along with vmswitch). After creation everything works fine until reboot, after which we are observing duplicates of packets ie:

18 bytes from xxx: icmp_seq=1 ttl=128
18 bytes from xxx: icmp_seq=1 ttl=128 (DUP!)
18 bytes from xxx: icmp_seq=2 ttl=128
18 bytes from xxx: icmp_seq=2 ttl=128 (DUP!)

If we remove VMSwitch and create it again, everything works fine until reboot.

MacAddress/IP configuration is always the same and doesn't change between reboots. We investigated the network, but it seems that those macaddresses exist only on that host and we see (using Wireshark/tcpdump) that duplicates are indeed coming from that server. If we use different network card (Intel x550) added in PCIe slot to create VMSwitch on that server in same way it all works fine. If we use those Intel x722 cards without VMSwitch there are no duplicates.

Mobo: X11SPH-nCTF + built in Intel X722 for 10GBASE-T
Processor: Intel Xeon Silver 4110 2.1GHz
OS: MS Hyper-V Server 2016 Version 10.0.14393 Build 14393 + all updates (also tested on MS Windows Server Standard 2016 + all updates)
Driver: c:\windows\system32\drivers\i40eb65.sys (, 996.54 KB (1,020,456 bytes), 2/19/2018 11:50 PM) (from latest 23.1 Driver Pack)

We don't see anything in logs. We tried reinstalling, even with different OS, situation seems to be the same.
We have the same OS + VMSwitch configuration on different Motherboards/Network Cards but we don't observe any problems there.

We tried to contact vendors, their responses:

Intel: go and talk to OEM (supermicro).
Supermicro: we had some people informing us of this issue; then silence when asked if and when they will investigate

Anybody has any suggestions?


Staff member
Dec 21, 2010
Usually, that is a driver issue. Intel issue but they are not providing support to the end user.