Anyways, I purchased a TPLink C1200 router to solve the poor range problem. You have to be careful buying routers: there are still many out there with 100Mbps ethernet ports. I'd consider modern to be 4x 1Gbe ports and AC wifi, and the C1200 seemed to have the best range/cost ratio with those options. It works great. I later noticed that there was a cable hook up right behind the server cabinet, so I moved the modem and router to the shelf above my homelab.
Originally, the headnode was connected to the wifi via a usb wifi adapter. This worked ok, but obviously wasn't ideal.
|Network diagram drawn with draw.io|
I'd like to replace the wifi link with an ethernet link. Since the IPMI network usage is tiny, and I have extra ports on that switch, I realized I could connect the router to that switch without a performance hit. Doing that means that the ethernet adapter on the motherboard connected to the ipmi switch has to have two different static IP addresses and subnets: one for the original ipmi, and one for the router. Turns out this is fairly simple to do using nmtui. Just edit the connection you want to add an IP address to, go to add address, add in the new IP address and subnet mask, e.g. 192.168.1.100/24, put the router's internal network gateway (usually just the router's IP, which is usually XXX.XXX.XXX.1) as the "gateway" and "dns", then make sure "never use this network for default route" is unchecked, bring the interface up and down, and you should now be able to access both networks from one interface. The route command is useful for troubleshooting. Here are some links I found useful: 1 2 3 4 . And if you need to cross the router between subnets: 1. I also set the static IP for the headnode in the router using the router's administration page (accessed by typing the router's IP into a browser and entering the administrative password) so that the router's DHCP wouldn't try to double assign the headnode's IP.
I also: 1. edited my firewall and moved the ipmi interface to the public zone, 2. updated the ddns (router) and noip settings so I can access it remotely, 3. got all of the wireless devices on the new wifi network.
Yay for more stable internet.