When an RPC server is started, it will tell portmap what port number it is listening to, and what RPC program numbers it is prepared to serve. When a client wishes to make an RPC call to a given program number, it will first contact portmap on the server machine to determine the port number where RPC packets should be sent.
Portmap must be started before any RPC servers are invoked.
Normally portmap forks and dissociates itself from the terminal like any other daemon. Portmap then logs errors using syslog(3).
This portmap version is protected by the tcp_wrapper library. You have to give the clients access to portmap if they should be allowed to use it. To allow connects from clients of the .bar.com domain you could use the following line in /etc/hosts.allow:
You have to use the daemon name portmap for the daemon name (even if the binary has a different name). For the client names you can use the keyword ALL, IP addresses, hostnames or domain names.
For further information please have a look at the tcpd(8), hosts_allow(5) and hosts_access(5) manual pages.