Looking to add two 2.5Gbe ports to my pfSense installation as I now have >1Gbps internet. I also have two other devices with 2.5Gbe ports but can’t utilise them as the rest of my network is 1Gbe.
Would this do for a pfSense install on a Proxmox machine?
And would this be an okay switch for the other devices? I have 1Gbe hardware for the rest of the network.
You need FreeBSD driver support.
And don’t link to storefronts, we don’t want to buy stuff. Link to manufacturer site which also has all the specs to answer your questions.
Well, really he needs pfsense driver support. Its different though pfsense is based on FreeBSD and does use some of their drivers. Whether his specific Realtek 2.5gb NIC has driver support will be hard to tell.
Sadly FreeBSD and pfsense don’t have the same drivers in the first place and then now the typical pfsense that people use (CE) is based on FreeBSD 12 while pfsense plus is based on FreeBSD 14, so different driver support even between pfsense versions now.
Proxmox is just Linux/Debian. You can use whatever as long as you stick to vmbr / bridged networking for pfSense… The driver will run in Proxmox kernel and Linux isn’t nearly as picky, and pfSense will just use the virtualized driver.
Proxmox VE Kernel - Proxmox VE (see note about 6.2 LTS ; if you’re running bleeding edge)
If you’re passing through a whole device using PCIe passthrough/vfio in Proxmox, to pfSense - then you’ll need a pfSense/FreeBSD driver that usually probably ships with pfSense.
Turns out pfSense 2.7.0 preview is based on FreeBSD 13 which comes with a revamped virtio driver that performs much better… which lets you sidestep the old pfSense kernel/driver issues because you can rely on Linux drivers instead.
If you’re looking at other options to pfSense, OPNsense is using FreeBSD 13.1 … or you could also try the OpenWRT x86_64 ext4 image,… or VyOS … they all come with more modern kernel and drivers.
A bunch of us had a heated discussion a while back re BSD and as part of it we touched on pfSense in Proxmox virtualized performance:
@guru4gpu did some very cool and informative testing
Thanks for the thorough response. So it sounds like it has a high chance of working, then?
I’m running pfSense 2.6.0 which states is FreeBSD 12.3. Could switch to dev version which is 2.7.0 but things are working so I don’t want to break them! 
Proxmox (which is the host for my pfSense VM) is running 7.1.8 but has many updates available - I’ll get 'round to those some time soon.
Put in dual NIC, one for WAN, one for LAN, then into the switch I linked, and off to my other PCs. Then have a Linux bridge from the 2.5Gbe LAN port with my other 1Gbe ports so I can then send that to the rest of my network, yeah?
Didn’t really think of this option. Smart. Certainly overrides any FreeBSD compatibility problems. I use passthrough and checked compatibility before buying, so this never was an option.
You can even spin this further with multiple bridges. for multiple LAN outs and VLANs. But I’m a simple man and I just use physical NICs 
For completeness, there’s also the SR-IOV. However, those nics tend to be fancy and expensive and two and 2.5 gig is unlikely to have it (x550 has it for example, might be an ok buy on ebay)