This question already has an answer here:
I have an ubuntu box at a local IP behind an Arris router from my ISP. I've setup port forwarding on the router for port 80 such that it forwards TCP/UPD to the local IP of the ubuntu box.
However, I cannot telnet using the public IP, and I can't access apache's welcome page on ubuntu via the public IP. I can telnet to ubunut's local ip from my mac on port 80 and can ssh into it as well. I have also disabled the firewall on Ubuntu for testing, yet I'm still unable to access ubuntu via the public IP.
I have checked and port 80 is open on the public IP so is 22, but not 21.
Not sure where to go from here. Any advice?
Edit: The output of traceroute is as follows:
traceroute to 126.96.36.199 (188.8.131.52), 30 hops max, 60 byte packets praha-4d-c1-vl55.masterinter.net (184.108.40.206) 0.499 ms 0.493 ms 0.544 ms ae-5-5.car1.KansasCity1.Level3.net (220.127.116.11) 149.079 ms CABLEONE.car1.KansasCity1.Level3.net (18.104.22.168) 146.839 ms 146.722 ms CABLEONE.car1.KansasCity1.Level3.net (22.214.171.124) 146.163 ms 146.822 ms * * * * * * *
Which I think means that CABLEONE.car1.KansasCity1.Level3.net is not allowing anything to get past it. But what does that mean exactly?