Unable to start up LANSA Listener because of port number conflicts

Date: 15 May 2008
Product/Release: LANSA for iSeries
Abstract: LANSA listener default port number 4545 conflicts with other third party software
Submitted By: LANSA Technical Support


When viewing the LANSA Listener joblog after not being able to start up. You may encounter this error message:

Native error: 0000003401 CPIC error: 0000000020 in bind

The most likely cause is that the port is in use.


Use OS400 command NETSTAT (Option 3) to check which ports are in use.

Sometimes another program can 'reserve' a port number, so that even though the port appears free, the error will occur. Use CFGTCP (Option 21, then Option 1) will show the service table entries.

One such program which might be using the default LANSA listener port is IBM's DataMirror iCluster. This adds port 4545 to the service table by default.