RPC / Portmapper

What is Portmap

Portmap is a server that converts RPC program numbers into DARPA (Defense Advanced Research Projects Agency) protocol port numbers. It must be running in order to make RPC calls.

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. Portmap logs errors using syslog.

Commands

1) rpcinfo

-d (debug) prevents portmap from running as a daemon, and causes errors and debugging  information to be printed to the standard error output.

-l (localhost only) causes portmap to only bind to the loopback interface.

-v- (verbose) run portmap in verbose mode.

  

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:

The RPC portmapper is a server that converts RPC program numbers into TCP/IP (or UDP/IP) protocol port numbers. It must be running in order to make RPC calls to RPC servers (like a NIS or NIS+ server) on that machine. 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.

Since RPC servers could be started by inetd, portmap should be running before inetd is started.

For secure RPC, the portmapper needs the Time service. Make sure, that the Time service is enabled in /etc/inetd.conf on all hosts: