Airport Extreme issues bridging with ISP router/modem

[macduke]

EDIT: Solved. Disable residential gateway function and put the Airport back into regular DHCP/NAT mode from bridged.

Well, this is a weird one.

I've got my Airport Extreme basestation (802.11ac) setup in bridge mode connected to an ISP provided cable modem (Hitron CGNVM) that has routing capabilities. Everything has been pretty fine until I started adding Ring security cameras (doorbell pro, chime pro and floodlight cam) to my network. I've gone through a lot of troubleshooting with them but haven't been able to figure anything out yet except that their products seem kinda flakey.

So the issue, from what I can tell, is that they don't like connecting to my bridged AEB. I can connect them fine to my iPad Pro in hotspot mode. What's even weirder is I had everything setup and working fine with all three devices (although initial setup with the doorbell and chime was tough and required customer service help), though things started acting weird a little while after I added the floodlight cam earlier last week. Then the chime went offline along with the floodlight cam at the same time (according to support logs) and the doorbell has stayed online without any issues (which is really confusing the Ring people).

What I'm trying to figure out is how to connect the modem/router thing to my AEB, but have my AEB handle DHCP because I think the issue might be with that? Although I might need a static reserved IP address set up for the router to the AEB? The problem is that I have to use this modem/router thing because when my wife expanded her daycare last summer, we got everything officially licensed (required for the expansion we were doing in our state) and the fire marshal requires a home phone line, or cable phone line with battery backup (which we have). So their special modem is connected to the house phone system for only $10/mo and we never use it, but they do occasional inspections so we can't get rid of it unless we want to spend $60+/mo for AT&T home phone outside of the cable providers. And before this I would buy my own modem (Motorola Surfboard DOCSIS 3.0 with no router built-in) and never had problems. I've got the router/modem thing configured with the WiFi turned off because it's garbage compared to the beamforming range of the AEB.

So I guess I'm trying to figure out if there is some way to pass the AEB the unrouted connection from the Hitron without fouling up the phone line stuff that the box has to do? Otherwise if I have DHCP turned on with the modem, I run into a lot of issues trying to play things like Xbox Live and other glitchiness (I think it was giving me double NAT issues or something).

Thanks!

 

[techwarrior]

This Modem\Router (Hitron CGNVM) doesn't seem to support Bridge Mode per se, but has an IP Passthrough option which is intended to allow you to use a port on the Modem\Router to pass through to a second router. The ISP must give you a second IP address for this to work. Some details here. In this setup, the Hitron device would handle the phone connection, and all other traffic would use the AP Extreme to connect wirelessly, and AP Ethernet ports. The only connections to the Hitron would be phones, incoming cable, and one port to pass the second IP through to the APExtreme for all other connections. You would also want to disable WiFi on the Hitron in this setup, to avoid interfering with the AP network.

Likely, AP Extreme relies on local DNS names which it learns through DHCP. In bridge mode, AP Extreme never learns the DNS names of local devices, so it possibly is unable to resolve to establish service connections to the ring devices.

Alternately, maybe the ISP has a modem which supports phones, but has no router included?

 

[belvdr]

This Modem\Router (Hitron CGNVM) doesn't seem to support Bridge Mode per se

The manual:

https://mediacomcc.custhelp.com/euf/assets/documents/modem user guides/Hitron CGNVM_User Guide.pdf

Page 59 says you can disable the "Residential Gateway Function" to disable routing (i.e. enable bridge mode) if you want to use another router behind it. I'm not sure if that will impact the phone service though.

 

[macduke]

The manual:

https://mediacomcc.custhelp.com/euf/assets/documents/modem user guides/Hitron CGNVM_User Guide.pdf

Page 59 says you can disable the "Residential Gateway Function" to disable routing (i.e. enable bridge mode) if you want to use another router behind it. I'm not sure if that will impact the phone service though.

Thanks! I should have updated this thread as I figured it out a few hours after posting and messing around with different configurations and then having to reset everything because I couldn't access the router over WiFi any longer and don't have an ethernet adapter for my MBP.

This is absolutely right. Basically what I did wrong was I let the piece of crap modem do the routing too and then bridged the AE. This flips it around so that the modem just acts like a dumb modem and all the routing is back on the AirPort, which is probably for the best anyway.

Thanks everyone! Networking crap is NOT my strong suit. Especially since about every modem and router uses different names for certain functions. And there are so many freaking acronyms! This thread can be closed.