Ports question???????

[DazzaC]

Hi guys I am looking for some information in the form of a technical document that details those ports on a PC system, what they do, what they are used for, etc to give me a better understanding.
Can anyone point me in the direction of some useful information? Thanks

 

[JasonDeckard]

Ports allow applications to communicate over networks.

People often assume to know which application is using a port based on the port number. For example, port 23 is commonly used for telnet, and port 80 is commonly used by web servers. A list of commonly used ports can be found here:

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

An application doesn't have to listen on its well-known port. Telnet can just as easily listen on port 8432 as it can on port 21 (or any other port number). To find out what application is using a port in windows XP (this may be true on 2000 and .NET as well), use the command netstat -ano to see a list of used ports and the ID number of the process that is using the port. You can then use tasklist on the command line to see which application is associated with that process ID.

On most operating systems, port numbers 1023 and lower can only be used by applications running as the super user.

Regards,
Jason Deckard

http://www.closedsocket.com/

 

[FaiTHLeSS]

Heres a list of port numbers and the general uses but you can change what port services run on, so these are default ports for those services, just google search to find out more about them or read the RFC's.

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

 

[2ffat]

Also look a faq83-3149.


James P. Cottingham

^{There's no place like 127.0.0.1.
There's no place like 127.0.0.1.}

 

[vop]

You might want to try out 'AWPTA - Atelier Web Ports Traffic Analyser' (shareware):

http://www.atelierweb.com/pta/index.htm

or

http://www.snapfiles.com/get/awpta.html

I does real-time mapping (plus content sniffing, and logging) of ports to processes (applications and services)! You get 15 executions or 15 days to try out this tool. NETSTAT is nowhere near complete in what it monitors - plus there is no easy way to get a hardcopy log for port usage.

You can also selectively stop traffic monitoring and logging for items that are no longer of interest and only focus on newly appearing or unfamiliar items.