Anyway to determine which NIC is in use?

[IroesStrongarm]

Looking for some guidance. I'm about to setup a new TrueNAS VM and I'd like to directly pass my second 10Gb NIC to it. My board has two total and as far as I can tell they are in different IOMMU groups so should be able to be passed separate from each other. The first one is currently in use as the main connection for the server and basically all my VMs.

I know I can see the name of the interface that's currently in use. My question is, is there a way to see which of the two, based on the IOMMU grouping, that is being used?

I believe worse case I could pass one through, and if my connection to the server breaks, I can just restart the whole server as long as the VM doesn't autostart back up. I would ideally like to avoid breaking things however if possible.

Any tips would be appreciated. Thank you.

 

[bobmc]

lspci -vvn -s 0n:00.n | grep Serial

should display the mac address of the adapter(s) so you should then be able to cross reference from there

 

[IroesStrongarm]

lspci -vvn -s 0n:00.n | grep Serial

should display the mac address of the adapter(s) so you should then be able to cross reference from there

Do I need to alter this command at all? I tried it as is and got:

lspci: -s: Invalid bus number

EDIT: Nevermind, I figured out what I was doing wrong and this definitely outputs exactly what you said it would. Thank you!! I will cross reference the MAC addresses from here

 

[IroesStrongarm]

Turns out they both output the same serial number, so sadly a dead end on that one. But I learned how to manipulate with lspci better than before, so definitely a net positive. Thank you.

 

[IroesStrongarm]

Okay, got the solution. Sharing here for anyone in the future.

lshw -class network -businfo

This gives me the name it goes by and the bus ID and from there I can easily reference what I need.