Port Forwarding randomly stops working


Occasional Visitor
I have a server running on a raspberry pi on my network. The Pi has a static address ( and the server port is 8504
I wanted to access the server from outside the network, so I setup port forwarding to forward external port 30180 to internal : 8504 TCP

I have the default asuscomm ddns setup and access the webserver like this ddns_address:30180 and it works perfectly well, except that once in a while it stops working and then in a couple of minutes it starts working again.

When the external connection breaks, I'm still able to access the server locally

I have UPNP turned off. Any tips on how to resolve/troubleshoot this issue? Maybe I have to change my dynamic dns to something else? duckdns?

Thank you.
Last edited:


Part of the Furniture
Check your router's system log for the time the problem occurs. It's possible that the router or some service has restarted itself. Also check that your DDNS name is resolving to the correct IP address during the period when you loose access.


Very Senior Member
If your wan IP changes often then it could be a simple timing issue where the router doesn't send the update to Asus soon enough, hence the delay. (Which I assume Colin was heading towards with his post). I forget offhand if you can adjust this for Asus ddns, but certainly it is possible with most 3rd party ddns offerings. It could also be a timing issue with asus ddns services. If you *need* a more stable platform, I would certainly suggest using another ddns service provider or at least trying one out to see if it resolves your issue (many can be tried for free)

I suppose it also comes down to how you define "once in a while" :)


Occasional Visitor
Thanks @ColinTaylor and @dosborne for your replies. It surprisingly didn't occur today, or maybe it went down and I didn't notice. I'll keep an eye out it if it happens again and try to troubleshoot.


Occasional Visitor
I changed the ddns provider to noip.com from the default asuscomm.com that Asus provides. I noticed that the old asuscomm.com dns name still works, I'm guessing they don't delete it from their system and it'll continue to work until my external ip changes.


Occasional Visitor
Update : After a week of testing looks like asuscomm.com ddns was the culprit. After changing to NoIP I haven't had any downtime at all.
Also my IP probably changed this week cause my old asuscomm ddns doesn't resolve anymore (after replacing it with noip)

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