Port Forwarding not working on RT-N66U with 380.68_2

[Texas_User]

Yesterday flashed my RT-N66U with 380.68_2 and now port forwarding (UDPs 123, 500, 4500) stopped working. Pls help.

A screen shot is attached to show the setup.

 

[ColinTaylor]

How are you testing this to determine that the ports are not working?

 

[Texas_User]

How are you testing this to determine that the ports are not working?

a) Checking for it at "https://www.yougetsignal.com/tools/open-ports/"
b) The device (T-Mobile CellSpot) that requires the ports to be open is not able to connect to the interent

 

[RMerlin]

I think you are confusing port forwarding and outbound port opening. Some of these ports in your screenshot make no sense as forwarded ports. For instance port 123 - that would imply your device is an NTP server and it needs to be reachable by the rest of the world.

Double check which ports have to be forwarded and which simply have to be open outbound - by default, Asuswrt does not block any otubound port.

If your device uses port 500, then try adjusting the NAT helper for IPSEC on the router. You can also try disabling NAT acceleration.

Bottom line, your issue is most likely not with opened ports, but with something else.

 

[ColinTaylor]

All the official documention I can find about the T-Mobile CellSpot talks about those ports being "open", not forwarded. So as RMerlin pointed out all those ports are open anyway so you might as well remove the port forwarding entries.

 

[Texas_User]

@RMerlin @ColinTaylor Thank you for your quick responses. I have removed the port forwarding entries.

Dumb Question: If all the ports are open then why is it that when I check for these ports (123, 500, 4500) on https://www.yougetsignal.com/tools/open-ports/ it shows that these are closed? Just curious. I will keep digging as well.

Thx

 

[jim769]

Probably because there only open outbound not inbound.

 

[ColinTaylor]

Dumb Question: If all the ports are open then why is it that when I check for these ports (123, 500, 4500) on https://www.yougetsignal.com/tools/open-ports/ it shows that these are closed? Just curious. I will keep digging as well.

It's a question of direction, and whose perspective it's being viewed from.

From the CellSpot's perspective it needs outgoing ports to open (not blocked). The Asus does not block any outgoing ports, they are all open.

From the perspective of www.yougetsignal.com, it is testing whether there is a server attached to your router that is listening for incoming connections on certain ports. For example if you were running a web or mail server. You aren't running any publicly accessible servers on port ports 123, 500 or 4500 so they show as closed.

 

[Texas_User]

@jim769 @ColinTaylor Thanks and it makes sense.

It is possible that my CellSpot has an issue. I will replace and check.

 

[RMerlin]

CellSpot relies on IPSEC I believe. Try toggling either NAT acceleration (LAN -> Switch Control) and IPSEC Passthrough (WAN -> NAT Passthrough) first.

Try also a forum search for Cellspot, I believe people discussed it in the past, someone might have posted instructions on getting it to work properly with Asuswrt.

 

[Texas_User]

CellSpot relies on IPSEC I believe. Try toggling either NAT acceleration (LAN -> Switch Control) and IPSEC Passthrough (WAN -> NAT Passthrough) first.

Try also a forum search for Cellspot, I believe people discussed it in the past, someone might have posted instructions on getting it to work properly with Asuswrt.

Ok. Will try. It had stopped working the moment I had flashed the router with the upgrade. Thus I thought (maybe naively) that it had something to do with the upgrade.

 

[Texas_User]

To close out this topic.

After unsuccessfully trying everything, I reverted back to 380.66_2 on my router (RT-N66U) and viola the CellSpot started working again.

Thanks to everyones for helping me troubleshoot it.