What is the purpose of eth1 interface in Qubes-Whonix?

Qubes-Whonix
1

I’m trying to get my head around what purpose the eth1 interface serves in Qubes-Whonix. Obviously the vif interface is for connection to the workstation and eth0 is for connection to the upstream NetVM, but what is the eth1 interface for?

It seems to me that I can set eth1’s status to down and everything seems to function correctly, but I could be missing something.

It would also be great if someone could point me in the direction of the scripts responsible for bringing up these interfaces. I’ve read /wiki/Dev/Whonix_Networking quite extensively but the Qubes-Whonix sections are slightly lacking.

Thanks.

2

See comments in file /usr/lib/qubes-whonix/init/network-proxy-setup.

3

Thanks for the answer.

My follow up is rather trivial so feel free to ignore, but given that eth0 and eth1 end up having the same IP address, wouldn’t Tor be able to establish its bindings with just eth0 and not the dummy interface? I’m rather unfamiliar with how sockets and bindings behave in the face of multiple interfaces with the same IP address.