Question:

Which TCP ports does the Antelope orbserver process use?

Answer:

The default port for orbserver communications is 6510. This piece of trivia can be found in $ANTELOPE/include/orb.h:

#define ORB_TCP_PORT 6510

A different port may be used by launching the orbserver with the -p option, specifying an alternate port number for the TCP-based communications. For more detail, see the orbserver(1) man page. When a non-default port number is used, the name of the orbserver must be specified in the form "server:port" where "server" is an IP address or fully resolvable domain name, and "port" is the port number. If the "server" portion is omitted, "localhost" is assumed. If the "port" portion is omitted, the default port of 6510 is assumed. As a final note, these orbserver port-numbers may be given nicknames, which are specified in a parameter-file called orbserver_names.pf. For more info on parameter files, see the man page pf(5). To see which nicknames are defined on your system, type pfecho orbserver_names in your properly-configured Antelope environment. In the default distribution of Antelope 4.4, for example, port 6510 has actually been given the name ":anza". The system administrator for your site can use whatever is appropriate for your installation.

Some examples of possible orbserver names and their interpretations:

bbarray.ucsd.edu        # orbserver on port 6510 at UCSD
bbarray.ucsd.edu:6510   # Same thing (fully spelled out)
bbarray.ucsd.edu:anza   # Same thing, given default configuration
132.239.4.43            # It's OK to use the IP number instead
132.239.4.43:6510       # Again, unnecessary mention of default port
localhost               # orb running on port 6510 locally
:                       # Same thing!!
:31415                  # orb running on port 31415 on local machine
localhost:31415         # Same thing
fake.address.edu:31415  # orbserver running on port 31415

The caveats about choosing orbserver port-numbers are the same that apply to all such client-server applications. Namely, one must make sure that port is not already being used on the machine running the orbserver; any intervening firewalls must be configured to allow passage of TCP packets on that port, or you will have difficulties; port numbers must be below 65536; and assignment of ports below 1024 usually require root priveleges.

One final catch: there are a few port-numbers that have become quite popular with hackers for unseemly activities. These port numbers are often widely firewalled, and it is appropriately difficult to convince competent system administrators to un-block them. Be aware of this if your "convenient" quasi-random port selection seems to be blocked everywhere; you may need to make a different choice.

Take a look at the man page Orbport(1).

For further details on port-number issues, start with the man-page on services(4) describing /etc/services.