I have a Ubuntu 11.04 system running 24/7 as webserver and backup system. It worked until Friday morning. On Friday some changes were made regarding my internet connection (adding internet-tv to it), and the same day internet went down because of a malfunction in the power of the internet connection in the neighbourhood distribution system (sorry - I don't know the proper english name for it). They said this was unrelated, and that for the tv to work, nothing had to be changed in the wiring.
Yesterday internet was repaired, and it all seemed to work. However today I discovered that it's not possible to reach this machine from the outside. On the local network it all works.
* I can SSH, I can open webpages on the local network, from another machine.
* I enabled UFW on the machine, allowed ports 22 and 8080
* I have set port forwarding on my router (Fritzbox 7170) to those ports.
* The DNS for the domain name seems to work properly.
* My ISP allows for port blocking, which I checked, and nothing changed, so no ports are blocked from their site.
I don't have any ideas what to do next. What else can this be?