I want to know if port 139 TCP is open from a server on one domain to another. How would I do this?

I know that I can use Telnet to test port 25 to a server with Exchange installed - but that only works because Exchange answers the telnet request - is that right?

How do you test the link if there is no program on the other end that will respond to telnet for example?


Check out nmap: http://nmap.org/

nmap -p 25 example.com


  • That's brilliant - thanks. The line actually needed to be "nmap example.com -Pn139" but that worked perfectly. Thanks for that. – Kieran Walsh Apr 7 '11 at 11:58

Just use

telnet myserver.com 139

If you're on a Linux/Unix box, I recommend you to check nc

man nc
  • As I said in my original post this will only work if there is a program on the remote side that is ready to accept 139 requests - isn't that right? What if there is no such program? – Kieran Walsh Apr 7 '11 at 7:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.