Portforwading through 2 routers (Arris and Asus)

[Lyckster]

I've been struggling all day to get my 2 routers to portforward, anything at all...

I have a mandatory modem/router from TimeWarner, the dreaded Arris TG1672
And my ASUS AC-RT5300

However, no matter what I do, I can't seem to portforward on this setup.

The link is - Arris -> Ethernet Cable -> Asus -> WIFI -> my PC

I have disabled the wifi bands on the Arris modem, so it should just act like a modem.

The first thing I tried was to simply configure the Arris router to DMZ the ASUS router.
The external IP of my ASUS router is 192.168.0.4

I changed my PC to a static IP address: 192.168.1.111

I tried setting up port forwarding from ASUS to my now static IP. But that didn't work. Then I tried setting the DMZ to my computer, which (if my theory is correct) should just have opened all ports on my setup. But after checking it, they are still all closed.

I then went ahead and disabled the FireWall on both the Arris and ASUS router. Still nothing.
Then I updated the firmware of my ASUS router.

Still nothing.

I tried putting the NAT of the ARRIS router in "bridge" mode. But that seemed to crash the router completely, and I needed to reset it after that.

I also tried port forwarding and triggering the ports I needed on the Arris router. But that made no difference either.

I even tried hooking my computer directly up to the ARRIS router with an Ethernet cable. Changed the DMZ to the computer's IP, and I could still not get a single port to show up as open...

I have tried everything I could think of, to make this work. And I have gotten nowhere.

I am hoping some genius on here, could help me out with some ideas?
(and no I am not leaving DMZ on, I am simply trying to get anything at all working at this point)

 

[kyzarvs]

You won't get double-layer NAT working for incoming reliably, ever (though as I'm sure you know, the internet connection will work going out).

Can you replace the ARRIS? There must be as many cable-capable routers available in the US as here in the UK. The only other thing if you must use the ASUS is have one of them on transparent / bridge mode. For example if you are just using the ASUS as a hotspot, turn off dhcp and let the ARRIS control it all once the ASUS has negotiated the wifi security, keeping everything on the same subnet.

 

[Lyckster]

You won't get double-layer NAT working for incoming reliably, ever (though as I'm sure you know, the internet connection will work going out).

Can you replace the ARRIS? There must be as many cable-capable routers available in the US as here in the UK. The only other thing if you must use the ASUS is have one of them on transparent / bridge mode. For example if you are just using the ASUS as a hotspot, turn off dhcp and let the ARRIS control it all once the ASUS has negotiated the wifi security, keeping everything on the same subnet.

Yeah my internet connection is fine. But the Arris router/modem is not good enough for my needs. That's why I bought the ASUS router. I can't really replace the ARRIS modem (to my knowledge) at least not right now.

I tried changing the NAT Mode to "Bridged" But that seemed to crash it. (at least the one time I tried)
The other options here are RoutedWIthNat and RoutedWithoutNat.. Do you think the ladder of the two, could help me?

 

[USAFRet]

The external IP of my ASUS router is 192.168.0.4

I changed my PC to a static IP address: 192.168.1.111

This is two different subnets. They won't easily talk to each other.

 

[kyzarvs]

I think you are over-complicating the problem. Unless you tell me some install-specific reason, there's no need to have separate subnets.

Set the web-interface IP of the ASUS to be something on the ARRIS subnet that DHCP won't allocate (192.168.0.254 for example)
Cable from the ARRIS LAN port to one of the ASUS LAN ports - not the WAN.
Setup Wifi security on the ASUS as required
Turn off DHCP service on the ASUS

Clients will connect to the ASUS, but talk to the ARRIS for an IP address. This allows you to port-forward to a wi-fi address as it's IP is given by the ARRIS and is on the same subnet, the ASUS just works as an Access Point, leaving the Router side of it unused.

If I've missed something in your setup that makes this impossible, apologies.

 

[USAFRet]

We see this type of thing daily here.

The original router is lacking in some way (bad WiFi?) so the 'solution' is...get another router.
And then it gets way too complicated.

When in reality, all that was needed is a properly placed original router, or a couple of Access Points around the house.
A second router needs to be dumbed down to be 'just an access point'. So why not get one of those instead.

 

[kyzarvs]

We see this type of thing daily here.

The original router is lacking in some way (bad WiFi?) so the 'solution' is...get another router.
And then it gets way too complicated.

When in reality, all that was needed is a properly placed original router, or a couple of Access Points around the house.
A second router needs to be dumbed down to be 'just an access point'. So why not get one of those instead.

Because for home use, dedicated AP's (at least here in the UK) aren't as plentiful, usually more expensive as they aren't as high-volume sellers and not using the routing functions does no harm? 😀

Don't get me wrong - I use a managed AP solution in my house using Netgear WNDAP350's with the controller box as well, but I own an IT business and I can write off the exorbitant cost for a home network against tax... All I'm saying is there's no reason to bin what he has just because it's a router + AP as opposed to a 'real' AP.

 

[USAFRet]

Right. Since he already has it, no need to toss it.
Just configure it properly.

 

[Lyckster]

Hmm I managed to get it working.

After I set the NAT mode to RoutingWithoutNat, my router crashed (again) to the point where I had to reinstall the firmware to get it back up and working.

After doing that however, I set the DMZ back to what it was, and it randomly started actually working...

I hate Arris. I don't even know why it didn't work to begin with. But it works now.

If anyone else runs into the same issue, I guess try reinstalling the router firmware manually.

 

[kyzarvs]

Hmm I managed to get it working.

After I set the NAT mode to RoutingWithoutNat, my router crashed (again) to the point where I had to reinstall the firmware to get it back up and working.

After doing that however, I set the DMZ back to what it was, and it randomly started actually working...

I hate Arris. I don't even know why it didn't work to begin with. But it works now.

If anyone else runs into the same issue, I guess try reinstalling the router firmware manually.

Glad you got it working 😀
If it fails again, I would stand by my solution / setup I posted earlier - you don't need to double-NAT and it is operating outside of it's design - if it is working for you now though, great news.