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Full Discussion: determining open ports
Top Forums UNIX for Advanced & Expert Users determining open ports Post 78160 by tom_xx_hu@yahoo on Friday 15th of July 2005 10:36:40 PM
Old 07-15-2005
As always I am a bit lost here.
Port starts from 0 (or 1 I don't remember) all the way up to 32555 (or sth similar). A port allocated by an active process (either serve or client) can be found by netstat. Everything else is not being used and so "available" for a process to allocate.

/etc/services is a differenet thing which may have implication for inetd or xinetd only. A port does not have to be "registered" in this file to be used by a process which has nothing to do with inetd.

There are more than one approaches to block a port. Conventional approach is via tcpwrapper. Now, people are more likely using (soft- or hardware based) firewall such as iptables in Linux.

I hope it answered all of your questions.
 

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HUNTD(6)							 BSD Games Manual							  HUNTD(6)

NAME
huntd -- hunt daemon, back-end for hunt game SYNOPSIS
huntd [-s] [-p port] DESCRIPTION
huntd controls the multi-player hunt(6) game. When it starts up, it tries to notify all members of the hunt-players mailing list (see sendmail(8)) by faking a talk(1) request from user ``Hunt Game''. The -s option is for running huntd forever (server mode). This is similar to running it under the control of inetd(8) (see below), but it consumes a process table entry when no one is playing. The -p option changes the UDP port number used to rendezvous with the player process and thus allows for private games of hunt. This option turns off the notification of players on the hunt-players mailing list. INETD To run huntd from inetd(8), you'll need to put the hunt service in /etc/services: hunt 26740/udp # multi-player/multi-host mazewars and add the following line to /etc/inetd.conf: hunt dgram udp wait nobody /usr/sbin/huntd huntd Do not use any of the command line options; if you want inetd(8) to start up huntd on a private port, change the port listed for hunt in /etc/services. NETWORK RENDEZVOUS
When hunt(6) starts up, it broadcasts on the local area net (using the broadcast address for each interface) to find a hunt game in progress. If a huntd hears the request, it sends back the port number for the hunt process to connect to. Otherwise, the hunt process starts up a huntd on the local machine and tries to rendezvous with it. SEE ALSO
talk(1), hunt(6), sendmail(8) AUTHORS
Conrad Huang, Ken Arnold, and Greg Couch; University of California, San Francisco, Computer Graphics Lab April 4, 2001
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