Port forwarding stopped working

[swainwright]

I have had port forwarding set up and working for the last 3 years for me to remotely view my CCTV. 

This has suddenly stopped working, if I use "can you see me" to check the port it says it isn't open.

I have factory reset my smart hub and set up port forwarding again but the port still shows as not open.

Any pointers as to what's causing the problem before I bin the router?

[Les-Gibson]

Is the camera viewable on the local network on that port?

[swainwright]

Thank you for your response. I view the cctv locally using a monitor connected to the DVR

[licquorice]

But can you access it from your PC, that will determine if the fault lies with port forwarding not working or the camera/DVR not functioning. The port will only be open if the camera/DVR is working.

If you can't see it via your LAN, you won't be able to see it remotely.

[swainwright]

Hi, thank you

Yes I can access it via a web service on my local network.

Sorry you might need to explain in more detail, do I not connect via a TCP/UDP port (which is the port opened on my router) to view externally,  where as locally using the web service I use the HTTP port?

[licquorice]

Yes, the port needs to be fowarded when viewing externally but the port only opens if there there is an application actively listening on that port. If you had been unable to access the camera locally it would have indicated the problem was not the port forwarding. 

If you have carried out a factory reset of the hub and port forwarding still isn't working, I'm not sure what else you can try.

Http is the application layer protocol that sits on top of TCP