> Subject:	Finding Unix ports
> 
> I'm currently configuring 8i and 11i apps.  Our current 7.3.4 install is
> using Unix port 1521 for the listener.  How do I determine which ports I
> have available in Unix to use for my other listener?

There's no guaranteed way to find out all ports that are being used or may be used. /etc/services in UNIX or %system_root%\winnt\system32\drivers\etc\services in Windows tells you all ports that are used by common programs. Programs started by inetd (in UNIX) must register their port numbers in /etc/services; other programs may choose not to do so. You can get a fairly complete list of common port numbers from
ftp://ftp.isi.edu/in-notes/rfc1700.txt
or
http://www.iana.org/assignments/port-numbers

The command netstat -an (for both UNIX and Windows) tells you all ports that are being used currently.[note] So it's possible that a program not running now and does not register its port in /etc/services may conflict with your choice of port number when it's started later. There's no way around that. That's why software vendors choose all kinds of port numbers.

However, if your question is about Oracle listeners only, then find all listeners on your server (probably only one) and look at the listener.ora file.

Yong Huang
yong321 AT yahoo.com

you wrote:

[note] Further, you can find the processes holding the ports open by lsof -i |
grep <portnumber> on UNIX/Linux (lsof is freeware), or netstat -ano on Windows XP
and higher, or using Tcpview (from sysinternals.com) or fport (from foundstone.com)
for older Windows . When the port is in some states such as TIME_WAIT, there may
be no user process opening it. But Tcpview or netstat -o may show System process
for it. NEVER kill System process!