Check the log file named <MPLS Topology Server name>_en_US_UTF-8.log (for example, INCHARGE-MPLS-TOPOLOGY_en_US_UTF-8.log) in the BASEDIR/smarts/local/logs directory in the MPLS Management Suite installation area. The discovery process writes an error message to this log file when it encounters a discovery error. “Error message formatting” on page 141 explains how to read error messages.
Checking the individual log files of the MPLS Monitoring Server and the MPLS Analysis Server might also yield useful information when troubleshooting discovery errors.