Oracle B32100-01 - Manual (Page 33)

Ports
Requirements 2-9
Why the Default Port for Oracle HTTP Server Is Port 7777 and Not Port 80
By default, the installer configures Oracle HTTP Server to use port 7777, not port 80.
Port 7777 is the default port because on UNIX, components that use port numbers
lower than 1024 require additional steps to be done as the root user before the
components can run. Because the installer does not have root access, it has to use a
port greater than 1024.
If you want Oracle HTTP Server to use a different port, such as port 80, use the "static
ports" feature, which enables you to specify port numbers for components. Although
you can change the port number after installation, it is easier to set the port number
during installation.
2.5.1 Checking If a Port Is in Use
To check if a port is being used, you can run the netstat command as follows:
prompt> netstat -an | grep portnum
2.5.2 Using Default Port Numbers
If you want to use the default port numbers for components, you do not have to do
anything. See
Appendix C, "Default Port Numbers" for a list of the default port
numbers and ranges. Make sure that at least one port is available in the port range for
each component. If the installer is unable to find a free port in the range, the
installation will fail.