I recently installed OpenWRT on my TP-Link Archer A7 router. It quickly occurred to me that, rather than looking at the three ethernet cables slung across the wall between the router and the cabinet that houses my solar equipment and Home Assistant server, why not run a single cable to that cabinet and install a switch there.
I am a pretty capable DIYer of all sorts and relatively tech savvy, but I know little about networking, so I am looking for advice/suggestions on the following:
Is it reasonable to use a router as a switch? (I think the answer is yes.) I have a second/backup router (Linksys MR8300) lying around that I can use in this project. I'd rather make use of what I have that is sitting idle if that is possible.
If so, does it matter which device is the router and which is the switch? The MR8300 has slightly better specs (mainly more RAM), so I'm leaning toward using that as the router. If I go the POE route (below), it would seem to make more sense to use POE to power the lower wattage router (the A7).
One concern is the lack of a convenient power outlet in/near the cabinet, so I was considering POE. Since neither router supports POE, I think I would need a POE injector at the router and a POE splitter at the switch, right? (Can I even power a router/switch with POE, as long as the injector can deliver enough power?)
Assuming all of the chaos above will work, do I also need to install OpenWRT on the switch or can/should I use the stock firmware?
The switch would only be for a single VLAN (IoT). I need it for the wired devices but can also
Does this setup sound do-able? Is it worth it? Are there ways to do it better?
for the most part, yes.
for the two devices you mentioned, yes.
you should use the faster device as router, as that one has to do much heavier lifting than a switch - this would be the mr8300 (by at least a factor of two).
this is where a dedicated switch with PoE-in (PoE-PD) might make (a lot) more sense. While you'd still need 802.3af/ 802.3at injector (be it just a single port injector or another PoE(-out) switch), at least the on-site switch could be powered from that. I do strongly recommend against 'passive PoE', in favour of standards compliant 802.3af/ 802.3at (or better) gear, which won't go up in flames of you connect the wrong ethernet cable.
You can (if you choose a supported one), you don't need to.
I would suggest to research the (second hand) market for devices like
as mentioned, you can run OpenWrt on that one, but don't need to.
Once you dabble with VLANs, you might quickly feel an urge to add another - so having (more-) spare ports is preferable.