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I am trying to send (using Pcap) raw 802.1Q (Vlan tagged) frames over a Hyper-V virtual network adapter (management OS) connected to a virtual switch, but for some reason the packets is not sent and I think it is rejected by the kernel as Pcap reports that it has sent the frame successfully.
Is there a special configuration to be done for the virtual network adapter or the virtual switch so that it can passes raw 802.1Q frames.
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Hi,
I would like to check if the reply could be of help? If yes, please help accept answer, so that others meet a similar issue can find useful information quickly. If you have any other concerns or questions, please feel free to feedback.
Best Regards,
Danny
Hi,
I would like to check if the issue has been fixed? If yes, please help accept answer, so that others meet a similar issue can find useful information quickly. If you have any other concerns or questions, please feel free to feedback.
Best Regards,
Danny
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By default, the virtual adapters are in access mode so the virtual switch will treat frames coming from them with 802.1Q tags as malformed.
If the adapter that you're using doesn't carry management OS traffic, convert it to trunk mode. If it does carry management traffic, then you'll want to create a new virtual adapter and convert that. Virtual adapters in trunk mode cannot carry 802.1q-less frames anymore so the management OS won't be able to use it.
Hi,
I already tried to convert the virtual adapter to trunk mode but still when I send a raw 802.1Q frame using Npcap, I don't see the packet at the receiver side and the number of transmitted packets counter in the windows network connection (see picture) does not increase which means that the adapter rejects the packet and does not send it.
Hi,
For creating a new adaptor you can refer to this:
https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/get-started/create-a-virtual-switch-for-hyper-v-virtual-machines
Thanks for your time.
Best regards，
Danny
-----------------------------
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Hi,
I have tried every vlan configuration on the virtual adapter (untagged, access and trunk), but still the adapter does not send the packet with a vlan tag injected into it.
Hi Mohamed，
Have you tried replacing the v-adaptor with a new one？Maybe you can try that.
If the issue remains，I would suggest that you try a microsoft support ticket. If the issue has been proved as system flaw, the consulting fee would be refund. You may find phone number for your region accordingly from the link below.
Global Customer Service phone numbers:
https://support.microsoft.com/en-us/help/13948/global-customer-service-phone-numbers
Thanks for your time.
Best regards,
Danny
-----------------------------
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I encoutner the same problem.
Let's say I have eth2 on Linux.
If I directly send raw 802.1Q frames via eth2, it didn't work.
If I create a eth2.6 and send IP frames via eth2.6, I can see 802.1q frames on another VM.
It looks like not vswitch problem. it maybe vmbus driver problem on linux.
Is there any command that I can set on eth2 so that I can send out raw 802.1q frames via eth2?
