3.13.06
Tech Troubleshooting Tip - #1
I hate supporting NAT from the CPE my company provides. Yet, it's a necessary evil that we have to troubleshoot, so here's some help.
If you ever want to test if a NAT'd service is forwarded correctly, you can use Telnet. Not sure how well it works from a *nix box, but Windows' telnet program works well due to the way it responds to a completed connection.
For example, verifying Remote Desktop through NAT:
Open a command prompt and type:
telnet x.x.x.x 3389 (x's representing the target IP address, followed by a space before the desired port). On a positive connection, the prompt window will go "blank" for about 30 secs, then disconnect. A failed connection give an error message.
I've found this to work on TCP port 1723 as well. Nice, unintrusive way to prove connectivity.
3:33 pm in networking | 1 person viewing0 ramblings so far