I would like to lock 1GBPS on my network cards that sometimes fall back to 100mbps. For now I'm using a custom-made bash script, but it would be amazing if network interface speeds could be assigned through the web interface.
I understand this, but it makes for us (Proxmox) no sense to implement something that is a workaround for no working HW.
The great thing about PVE is you have a full-featured Debian and free to do what you like.
You can set the speed with "ethtool".