Rebinding udp socket to new one - sockets

Question

As syslog uses the predefined socket port number of 514, is there any way to rebind this socket port number to any other port number specifically between 49152 and 65535. I am using Unix C 'gcc' compiler.
bash-3.2$ netstat -anp | grep udp
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
udp 0 0 0.0.0.0:2049 0.0.0.0:* -
udp 0 0 0.0.0.0:514 <-- needs to be changed 0.0.0.0:* -
udp 0 0 127.1.1.1:6688 0.0.0.0:* -
udp 0 0 0.0.0.0:4785 0.0.0.0:* -
udp 0 0 0.0.0.0:69 0.0.0.0:* -
udp 0 0 0.0.0.0:47451 0.0.0.0:* -
udp 0 0 0.0.0.0:613 0.0.0.0:* -
udp 0 0 0.0.0.0:111 0.0.0.0:* -
udp 0 0 0.0.0.0:1009 0.0.0.0:* -
udp 0 0 0.0.0.0:1012 0.0.0.0:* -
I need to change the 514 to the specified value.

Answer 1

gcc is simply a compiler and so we cannot change the port number of syslog application during compilation. Having said that, it is likely that one can configure the port, usually in the configuration files, and you should be able to set it to 514. Here is an example that talks about configuring both the client side and the server side: http://itvomit.com/2012/06/01/linux-sending-log-files-to-a-remote-server/ . Depending upon your system, I would explore how to change the port number.
We should keep in mind that if we change the port from 514 to X, then if remote clients send information to syslog, they they would also need to send it to the new port X and not 514. Here is a link on that explains how we need to change the client side config to redirect logging messages to a port number different from 514: http://docs.splunk.com/Documentation/Storm/Storm/User/Howtosetupsyslog