Adding 2.5g network card to Proxmox host

I installed 2.5G network adapters into a set of Optiplex 7050s using this adapter. The computers already had Proxmox installed, and were using the built-in 1G networking.

Adding the second adapter is fairly straight forward (and none of it specific to this exact situation)

In the host's shell, run

ip link

and find the new adapter name, for me it showed up as enp2s0

On that host, go to the System > Network section and create a new Linux Bridge device.

Fill in the "Bridge Ports" with the device name (e.g enp2s0) and maybe a comment.

Check the "Pending changes" diff is sane, then click "Apply Configuration" button.

Repeat for each host.