Software to find open ports?

[Chris01]

Hey all

is there such a piece of software that scans your router to find open ports?
if so, anyone know any free software?

thanks,

Chris

 

[Otacon]

I've used shields up to test before: http://www.grc.com/x/ne.dll?rh1dkyd2

 

[tolien]

There's this too - basically, it's nmap with a pretty interface stuck over the top.