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how to find out if a port is available on a remote machine?


 
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Top Forums UNIX for Advanced & Expert Users how to find out if a port is available on a remote machine?
# 1  
Old 08-03-2009
how to find out if a port is available on a remote machine?

hi,

I can ping into another unix machine, but I cannot seem to access a certain application. I think it might be because I am now allowed to connect to the port (because of firewall configuration).

How can I find out if I have access to a port on another machine?

thanks
# 2  
Old 08-03-2009
A simple first step is to attempt to telnet to the specific port
Code:
telnet <server> <port>

# 3  
Old 08-03-2009
using telnet, try connecting to that port: telnet ip_address port_num
if the port is open, you'll see something like:
Code:
yogeshs@yogesh-laptop:/tmp$ telnet 10.2.28.51 22
Trying 10.2.28.51...
Connected to 10.2.28.51.
Escape character is '^]'.
SSH-1.99-OpenSSH_3.9p1

now press ctrl+] and hit enter. when you get telnet> prompt, type quit and press enter.

if the port is closed, you'll see something like:
Code:
yogeshs@yogesh-laptop:/tmp$ telnet 10.2.28.51 222
Trying 10.2.28.51...
telnet: Unable to connect to remote host: Connection refused
yogeshs@yogesh-laptop:/tmp$


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