Background: I switched to T-Mobile for my Internet connection (via 5G) and, as far as speed and lack of interruptions, it works fine for me, but I have a few problems:
* I'm not asking about this, just noting it: The address of the TMO-G4AR device is 192.168.12.1 and cannot be changed (and certainly not from the .12 "subnet" (right word?)), which meant I had to reconfigure all my devices, some of which I forgot how to do.:-( (Ok now ;-) * The TMO-G4AR device is not a router, but it does NAT (I think it does DHCP also, but I'm not using that at all, I use static (IPv4) addresses), does not do routing, and cannot be switched to bridge mode. Trust me on those things that the TMO gateway device cannot do. There are some ways to get a different device that works on the T-Mobile network which can do (some of?) those things, but requires switching to a "business license" at a higher cost and paying for thruput. I had my devices working for a while (a few months) but had no occasion to do anything like ssh between them. Today I had a need and realized that I cannot ssh (or ping) between them because the TMO does not do routing. The question(s): I have a Ubiquiti Edge Router X which I used with my previous cable based ISP. I'd like to add it back to the LAN to enable communications between devices, but because the TMO device does NAT and so would the Edge Router, I'll have a double NAT setup -- I'm worried about that especially for my VOIP communications. I'm thinking about 2 (or maybe 3) solutions. 1. The simplest for me to explain is to put a 2nd Ethernet interface in each of my computers and then run one Ethernet interface (through a switch) to the TMO and the other Ethernet interface (possibly through another switch, depending on where I locate the router) to the router. I'm guessing that could be made to work, but that it would require some "gymnastics" to routing tables in each computer (or something along those lines). 2. The slightly more complicated one for me to explain is to somehow stick with one Ethernet interface per computer, run each to a switch, and have those switches interface to both the TMO and the Edge Router. Again, I'm guessing this could be made to work, and would require "gymnastics" of some sort. 3. Another possibility that I'm not real comfortable with, but maybe could work: The TMO-G4AR has two RJ-45 connectors that can be used to connect to "network segments". I could set up the Ubiquiti to handle communications on my LAN and also connect to one of those TMO connectors to provide access to the Internet (for the LAN), and use the other TMO connector to connect my (hardware VOIP devices) without a router, thus no double NATing for those. I do also use google voice VOIP from some of my computers, and that would be subject to double NATing. I don't play games or such, I do have one (smart) TV connected to the TMO (currently via the LAN) that I watch sometimes in the evening. Thus, except for the VOIP lines, I'm not sure I have much to worry about with double NATing. At the moment, I'm throwing these possibilities out for any comments you have to offer, and to help me pick the path going forward. Oh, one other thought: in my readng on the Internet, at least one person suggested that switching to IPv6 could resolve my (or somebody's ;-) problems -- if that is a solution, I might consider it. (IPv6 is Greek to me, and I've resisted it up-to-now because I feel somewhat secure behind NAT (and because it is Greek to me).) (Oh, related to that, I have no idea what the TMO device would do with IPv6.) Once I pick the path, I'll almost surely ask for more help for things like setting up the routing tables appropriately.
