I run a rails development environment, which runs a server I can access at localhost:3000. I was doing this again today, and went to restart the webserver and it started timing out.
After some time I ran
nmap localhost, and realised that 'ppp' is running on port 3000:
3000/tcp open ppp
I've never used PPP, and it's stopping me getting my work done. I tried
service pppd-dns stop, which appears to have no effect. I even tried
sudo apt-get remove ppp, but the port is still open, and I still can't start my rails server.