Use this tool to compare the running and startup (in NVRAM) configs of a Cisco router. If changes were made to the configuration but not committed to non-volatile memory, you can detect differences between the two configurations. Always compare running and startup configs before rebooting a router.
Cisco routers stop responding to SNMP queries while they are requesting a file from a TFTP Server. They also stop responding to SNMP while sending files to a TFTP Server. If you instruct a Cisco router to upload or download a new configuration file and it cannot comply, the action is attempted numerous times – repeating up to a minute. During this time, the router stops responding to SNMP queries. You must wait until the previous router action times out, and then try again.
After downloading both configurations, the comparison is displayed in the Config Editor or Viewer.