Port forwarding on CR1000B stopped working recently

I have port forwarding on port 2601 on my CR1000B to access a component on my system externally. It was working without a problem until a few weeks ago. I can no longer access the port. I've used a port check tool and the connection always times out. I deleted the original port forwarding on my router and recreated it without success. Has this happened to anyone else? Any ideas?

Accepted answers

miked_62

Turns out my problem is likely not due to a port forwarding issue. The problem may be with the system I'm trying to connect to (home security alarm). I appreciate everyone's advice. Thanks.

All comments

Capricorn1

Timeouts could be caused by failed port forwarding or the service not being up. Has anything changed on the device you are accessing that may have changed the port you are listening on? (Does that port respond as you expect it to when you try to access it from another device on your LAN?)

Have you tried switching to another port? Maybe something higher in the range, like 12601? Then, port forward 12601 to 2601 on the device. Maybe something "naughty" has been showing up on port 2601 (unrelated to your device) and is now blocked somewhere upstream. Higher port numbers tend not to be blocked.

miked_62

I tried what you suggested, but I'm still getting a time out error after switching to a higher port number. Port Check Tool now says that my original port (2601) is not blocked. Thanks for your help.

eric_b2

According to IANA, port 2601 is reserved for the zebra client.

https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?&page=48

I'm not familiar with that platform so I can't help with any suggestions but maybe routing from the router to the zebra server, which looks like it has its own routing table, could be causing an issue. (Assuming that's the target for your port forward). On the LAN side, are you able to connect to the target IP and port using a telnet client?

miked_62

Turns out my problem is likely not due to a port forwarding issue. The problem may be with the system I'm trying to connect to (home security alarm). I appreciate everyone's advice. Thanks.