Open Ports not being detected

I am a registered user of both Port Explorer and TDS 3. The system is a standalone XP Home version behind a Norton IS (NIS) firewall. When I run the Local Port Scan utility of TDS 3, it finds TCP ports (2281, 2282, 3566, 3567, 4882) that are in use by something but these ports aren't showing up in Port Explorer. Is this a bug in the TDS Port Scan and the ports are not in use, or is it a bug in the Port Explorer which allows an undocumented open port?

A full system scan by TDS shows nothing suspicous. Likewise scans with Norton AV and AVG by Grisoft and Adaware also detect nothing.

 

Local port scan, This is scanning your PC's local ports which are used by the system (local Host)and not the same as those connecting out of your PC to other computers and / or the internet.

The TDS help file says:
"This scanner works by attempting to bind sockets to local ports and also shows a graphical scan display in realtime. Starting at port 1 and working its way up (it can of course be cancelled at any time), it will attempt to bind to each port. If it can't, the port is displayed as being in use. Both UDP and TCP ports can be tested with this scanner."

PE sees all connectionsand teir states ie. Listening, remote etc. including hidden ones, out of your PC ie. to yout LAN or to the internet.

Hope this helps and have a Merry Christmas - Pilli

 

Well, that's a relief. I have been playing with it all night thinking both scans were supposed to be showing the same data. All ports shown on PE were also shown on the TDS, so the presence of some on the TDS which weren't showing up on PE had me concerned. When I wrote a rule to block those ports and rescanned the ones in the rule didn't show up, instead new ones did. And my hunt for the guilty process or service began... I was getting really frustrated till I logged back in and read your comment.

 

Hi!

What about open Ports from other protocols, like GRE, PPTP and so on...? Will i be able to see them with Port Explorer?

 

Hi Grut, Port Explorer will see any connection using TCP or UDP ports. Remote, Listening or Established.

HTH Pilli

 

Different protocols

Be aware that most such protocols actually use standard transport protocols such as TCP and UDP, so you can still for example use the packet-sniffer on them.