I’ve installed OpenWRT on an Edge router (ERX) and its made me want to custom firmware every piece of networking equipment I own.
I’ve got an ER4, AP Pro and PlusNet (BT) router lined up but I wondered if it’s possible to do anything with the Unifi switch I have? I know there’s OpenWRT images for the ToughSwitch line by Ubiquiti but looking at the OpenWRT forums it looks like the Unifi switches are a dead-end.
I’ve got a craving to hack/customise it but can’t find any options.
OK, I concede haha. You’re absolutely right that doing things Just Because ™ is as valid as reason as anything else, and as an engineer I shouldn’t be dissuading other folks from exploring. One thing I will say is that because my work develops network switches, it’s an occupational hazard that I’ve become less interested in going home and doing more recreational networking. I still do, but not on my “production” home network. I have a separate equipment stack for playing around with.
I would doubly recommend this: networking is a great big world that underpins so many things, but is often unsung and misunderstood, or even just not understood at all. Looking under the hood is seldom unenlightening.
You’ve pretty much arrived at exactly the reason why I don’t use Ubiquiti’s switch products, inexpensive and capable as they are. I’m a proponent of “fewer moving parts”, so it’s either self-contained network appliances (ie router, switch, modem) or tightly-integrated equipment with configurability and performance that overcomes the complexity burden. These controller-managed or cloud-managed devices are just adding points-of-failure, IMO.
Regarding the feature you mention, I think the industry uses the term “mirroring”, as in Port Mirroring or VLAN Mirroring. That said, the volume of traffic is basically a firehose and could potentially overwhelm whatever port or entity is to receive the mirrored traffic. High-end switches will instead forward traffic on a more granular basis, based on filters issued from the IDS for what constitutes suspicious traffic. You might consider reading about OpenFlow and Software Defined Networking (SDN) for how some of these scenarios are implemented, but this is getting rather deep into networking.
The refresher I was given a while ago to read for networking was The All-New Switch Book, second edition. It’s a bit old at this point, but it’s a solid foundation on Ethernet and standard network features.