Arris: **** SBR-AC3200P Multiple console support?

how can i choose which console will be my main one? the one i have set to my home console often gets disconnected randomly from XBL.

If I continue to use this gateway and attach a router that supports multiple xboxes would I be able to have Open NAT for all devices or do I have to remove the gateway altogether?

That would work, you would just have to make sure the new router would broadcast it's own signal. And it would have a separate login IP Address from your current one (which is most likely 10.0.0.1). You would have a whole new WiFi name and password as well.
It would be best to disable wifi on the Gateway, so you dont have two signals running at once. But with two devices, it can slow down the connection speed overall, so it would be best to just contact your provider and tell them you have your own router, and
would like to swap out the gateway for a regular cable modem.

i had the same exact problem man i run to 360s on one network came home and bam nat type strict try resetting your UPnP like disable it save settings then turn off the modem then turn modem back on and enable it and it should work it worked for me anyways

No, bridge mode normally wouldn't be required, but that's not an issue with the XBox One, it's Arris/Comcast to blame. This gateway is an all-in-one device, with modem, telephony, 4 port router, and wireless built in. But it has issues doing NAT for multiple
consoles (one of the first things I discovered after getting it), so it's recommended to put it in bridge mode with a broadband router behind it for the rest of the lan. That took some digging to discover over a year ago. When I had a standard Motorola surfboard
modem, prior to getting telephone through Comcast, I still use my own router, but had no issues-modern routers come ready, with upnp set up, and NAT working fine out of the box, 99% of the time. Now that I've found that it was (once again) a problem with the
(unbridged) Arris, I find that the XB1 seems to work pretty well without any special tweaking.

I was having all kinds of issues with moderate and strict NAT for our two XBox Ones, even though the two 360s were showing open NAT. It turns out that Comcast had sent out a firmware update to my Arris telephony gateway, resetting it, and changing it back
to standard mode from bridge mode. I spent the past week thinking it was either the new console or my routers (was occurring with both the Linksys E4200 and my newer Asus RT-AC66U, that replaced it). After five minutes in chat with a Comcast representative
this morning, the modem was back in bridge mode. Resetting the router and power cycling the consoles took care of the rest. All four console are now showing as open.