Connecting Raspberry Pi directly to eth1 to manage SSH

[Eksitus]

Hi,

 

SHORT VERSION: Raspberry Pi SSH into Unraid, no router possible.

 

I have a UPS that has no way of telling Unraid to cleanly shutdown. Therefore, I used its signaling LED voltage to determine the state of running on battery via GPIO and now I'd like the raspberry pi to communicate it to Unraid. Unfortunately I can't do it via router, since it won't be powered on during power loss, so I thought it could be possible to SSH into unraid via second NIC (eth1) and send the command to shutdown on the raspberry pi.

 

Is there an option to achieve this goal (maybe not exactly the way I described)? Does it require auto MDI-X cable or maybe linux VM and networking shenanigans? I'm looking for the least expensive and obtrusive way possible but I'll be glad to learn from every possible solution. In case it's nearly impossible I will simply run the wiring from the PC power button to RPI's GPIO but it'd like to avoid it.

Thanks in advance!  

Edited March 25, 2021 by Eksitus

[JonathanM]

6 hours ago, Eksitus said:

Unfortunately I can't do it via router, since it won't be powered on during power loss

Why not correct that? It seems to me keeping a few watts worth of infrastructure on a UPS is a whole lot easier than what you are trying to do. I suppose if you have shed loads of spare time on your hands and no money, then it would make sense, but considering you can get a small UPS for USD$40, I wouldn't think it would be worth the hassle.

 

Unless, of course, you are looking for an educational challenge and don't really care how much time you spend. In that case, I'd try using a plain ethernet cable, crossover cables haven't been required since 10/100 maximum speed was normal. Give the interfaces on Unraid and the raspi sequential static IP's on a different private subnet than what you are using for your main setup, and see how you get on.

[Eksitus]

3 hours ago, jonathanm said:

Unless, of course, you are looking for an educational challenge and don't really care how much time you spend. In that case, I'd try using a plain ethernet cable, crossover cables haven't been required since 10/100 maximum speed was normal. Give the interfaces on Unraid and the raspi sequential static IP's on a different private subnet than what you are using for your main setup, and see how you get on.

Thanks a lot! I'll try to educate myself more about private subnets and sequencial static IP and see what I can achieve with it. Actually you're right about this educational challange, I've only recently started building my advanced networking knowledge, so this project seems like a perfect fit to throw myself in at the deep end.