Hi guys, I am having problems with open ports in OSX tiger

Question

Hi, I have a home network and my computers have suspicious ports open, I dont know what they are , or if I have to close them or not.
Here is a local nmap scan
Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2006-09-16 11:43 CLT
Interesting ports on 192.168.0.100:
Not shown: 1678 closed ports
PORT STATE SERVICE
22/tcp open ssh --> I enabled SSH for remote login into this one.
5000/tcp open UPnP ( what is this ?! )
Interesting ports on 192.168.0.101:
Not shown: 1678 closed ports
PORT STATE SERVICE
427/tcp open svrloc ( what is this ?! )
548/tcp open afpovertcp ( have to disable file sharing here)
MAC Address: 00:05::3A (Apple Computer)
Interesting ports on 192.168.0.102:
Not shown: 1676 closed ports
PORT STATE SERVICE
427/tcp open svrloc( what is this ?! )
548/tcp open afpovertcp (have to disable filesharing... TOO)
3689/tcp open rendezvous( what is this ?! )
5000/tcp open UPnP( what is this ?! )
MAC Address: 00:C8:E8:6A (Apple Computer)
Interesting ports on 192.168.0.103:
Not shown: 1677 closed ports
PORT STATE SERVICE
515/tcp open printer
631/tcp open ipp ( what is this ?! )
5000/tcp open UPnP ( what is this ?! )
MAC Address: 00:16:CB:B7:DB (Apple Computer)
I would really appreciate any kind of help
Thanks!

Answer 1

Here's a list of "Well Known" TCP and UDP Ports Used By Apple Software Products...
http://docs.info.apple.com/article.html?artnum=106439
427 is SLP for Network Browser.
631 is Mac OS X Printer Sharing.
3689 is iTunes Sharing.
5000 is something to do with Windows...
http://www.grc.com/port_5000.htm
Might I suggest HenWen for watching/controlling your Ports/Activity?...
http://www.apple.com/downloads/macosx/networking_security/henwen.html