I am running LDM on a firewalled machine that doesn't allow access to remote portmappers. http://www.unidata.ucar.edu/packages/ldm/networkSecurityAndSetup.html states: ================================================ Currently, in order to start, the LDM requires that the portmapper program, usually called portmap or rcpbind on some systems, be running so that the LDM can register its remote procedure call (RPC) service. After that, however, the portmapper is not required because client LDMs will attempt to connect directly to port 388. Perhaps the best way to implement a secure LDM server would be to have the portmapper running but block or limit access to its port, port 111, via either TCP-Wrappers or a firewall. ============================================== However, after restarting ldm on a server, I see the message: FEEDME(moonbow.rap.ucar.edu): can't contact portmapper: RPC: Unable to send; errno = Operation not permitted Reading the source code protocol/h_clnt.c, this message is a result of an RPC failure. (And this failure resets the state of the connection.) For this particular machine, sometimes I see a delay of several minutes before I see the message: FEEDME(moonbow.rap.ucar.edu): OK This doesn't happen for the other two machines that are feeding this LDM server. Any idea why this error mesage happens on one machine, and not two others?