Thankyou, these look interesting. Some are very close in price to the APU2s. "Mini PC ethernet" seems to be a good set of search terms on Alix.
Ahah, now I can see them. That's super-useful, thankyou.
Ooh they actually have those in stock. Last time I looked at pine64 everything seemed to be OOS.
Any comments about quad-NIC brands? I presume I can't just buy anything 2nd hand and expect it to work. New ones seem to be most of 200AUD sadly.
Thankyou for the offer, really appreciate that. Alas shipping from US to AUS is a bit of a pain at the moment, I don't want to drag you into that. Auspost (government-run postage service) has an official US->AUS dropshipping service that I have been meaning to try out, I'd rather let them bite any difficulties.
I think pretty much anything that uses at least somewhat recent Intel controllers should be fine but I know for sure that Fujitsu designed NICs works =) https://wiki.freebsd.org/arm/RockChip#Tested_PCIe_devices_on_RockPro64
Do note that most (I think all tbh) listed non working PCIe cards is down to hardware compatibility and/or limitations not the OS/PCIe driver.
In the 21st century it's more of a problem just for BSD-based firewalls like pfSense or OPNSense, and also a problem of "cards/dongles with realtek are lower quality and may fail/overheat/whatever" more than a real realtek brand issue.
Realtek did some crummy ethernet controller hardware in the past, and even now it's not amazing but since they have not made a whole lot of new gigabit ethernet controller designs in a while, they did hardware revisions to fix stuff and software drivers matured a lot and worked around most/all issues.
As a general rule, if you can get your hands on an used server-grade Gbit (multiport) ethernet card it's going to be better, and you can get them for real cheap.
Dell/HP/Fujitsu/IBM will use either Intel or Broadcomm controllers and both will work ootb and fine on OpenWrt.
You can probably get buckets of those if you allow chinese sellers on ebay or even if you hit aliexpress. Boy they got a lot of used server stuff to sell you. I've been farming 10Gbit cards and SAS cards (for storage drives) like that for a while, and so far everything worked fine.
It's a different thing. Realtek ethernet controllers are not the same thing as Realtek ethernet switches (like 80% of unmanaged switches and a good qunatity of managed) or realtek sound chipsets, or anything else made by Realtek.
As other suggested Aliexpress has mini PCs.
Eglobal is the generic brand of Protectli.
If you need a full open source solution you can try flashing coreboot yourself, at your risk.
Since the Wan side is only 100Mbits, you could use a managed switch for the 2 wan connections, and connect it to a single port in the router. You needs to create to 2 Vlans in the same interface. In theory you could have 3 Vlans in the same interface.
It depends on your threshold on how reliable you need hardware to be. Realtek NICs "works" however targetting bottom of the barrel for pricing you do get what you pay for. There are a lot of silicon fixes/workarouds in Realtek's drivers, vendor isn't all that great (compared to lets say Intel, Chelsio etc) but it's cheap and pushes packets. You can more or less compare it to anything else in a similar position, cheap breaking pads vs more expensive/premium etc. Pricing doesn't necessarily always reflect on quality but in many cases (to some extent) there's a reason which may or may not be of importance for your scenario.
@CopperCassette needs 3 ethernet ports based on post: WAN1, WAN2, LAN
I was suggesting a SFF with 2 ports or even 1 port may be enough, if a managed switch is used and VLAN configured.
WAN/LAN traffic is only 100Mbits, plenty of bandwidth.
LAN can be segmented even more and have more VLANs, but hen 1Gbits may not be enough.