Is the Port Open?

[contsi]

How can you tell which ports are open on a router?
How do you open a port if it is not opened.
I do netstat -a on a PC, does this show all opened ports.
Can you run netstat on a router???

 

[criticalUpdate]

what kind of router? cisco, linksy?????

also you can start with logging on to grc.com and probe ports that's a good sanity test anyways...


Jeff

 

[contsi]

It is a Dlink 713P.....

 

[criticalUpdate]

Sorry don't know that one try getting the documentation for opening a port they probably have in on the website.




Jeff

 

[manarth]

I imagine you login to the web control panel (type

http://192.168.0.1/

in the browser address bar).

There should be a section called 'port forwarding' or 'virtual server'.

The ports won't be open on the router per-se, they would be forwarded to an IP address in the LAN, and if a PC is sitting on that IP, it will be whether the port is open on that PC.

Occasionally a router opens a WAN port for remote administration - it's usally 8080.

<marc> i wonder what will happen if i press this...[ul][li]please tell us if our suggestion has helped[/li][li]need some help? faq581-3339[/li][/ul]

 

[bcastner]

I use this little freeware utility to scan for open ports on a Windows workstation:

LPS - Local Port Scanner

http://www.petri.co.il/software/lps.zip

 

[mrbusy]

I use an application called SuperScan (downloadable at WebAttack.com) for my port scanning. This will tell you what ports your router is listening on. I would expect 23 (telnet) and possibly some administration ports (80, 8080, etc).

As Manarth rightfully points out if the router is port forwarding then you might see results which are actually services on hosts on the far side of the router.

http://www.iana.org/assignments/port-numbers

gives a list of all the well known, and many not so well known, port assignments.