I've run into a perplexing network issue that I've not been able to solve.
I had a network application that worked fine until an update. Then all of a sudden it quit connecting. It works with Mac, and Winblows, but no longer Linux. In this case, I use Playonlinux. The obvious reaction is that it is an application problem. But upon further review it appears to be a port issue. I ran some packet traces and noticed that during the login sequence, I get responses that certain ports of mine are unreachable. I tried turning the firewall off within Yast2, and it made no difference. I then started manually adding port exceptions in the firewall and one by one those went away, but the list was up to about 10 and it was growing. Which lead me to the question why are these ports even close by default? I thought unless blocked should default to open.
I did an nmap and here is what popped up:
nmap -p 30000-60000 localhost
Starting Nmap 6.25 ( http://nmap.org ) at 2014-05-06 21:56 MST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.0000070s latency).
Not shown: 29995 closed ports
PORT STATE SERVICE
30000/tcp open unknown
30001/tcp open pago-services1
32400/tcp open unknown
So you can see they are specifically closed! How can I make sure a range of port are open for UDP service? I tried to make a custom rule that says 30000-60000, but that is invalid apparently.
Any insite into this appreciated.
I had a network application that worked fine until an update. Then all of a sudden it quit connecting. It works with Mac, and Winblows, but no longer Linux. In this case, I use Playonlinux. The obvious reaction is that it is an application problem. But upon further review it appears to be a port issue. I ran some packet traces and noticed that during the login sequence, I get responses that certain ports of mine are unreachable. I tried turning the firewall off within Yast2, and it made no difference. I then started manually adding port exceptions in the firewall and one by one those went away, but the list was up to about 10 and it was growing. Which lead me to the question why are these ports even close by default? I thought unless blocked should default to open.
I did an nmap and here is what popped up:
nmap -p 30000-60000 localhost
Starting Nmap 6.25 ( http://nmap.org ) at 2014-05-06 21:56 MST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.0000070s latency).
Not shown: 29995 closed ports
PORT STATE SERVICE
30000/tcp open unknown
30001/tcp open pago-services1
32400/tcp open unknown
So you can see they are specifically closed! How can I make sure a range of port are open for UDP service? I tried to make a custom rule that says 30000-60000, but that is invalid apparently.
Any insite into this appreciated.