I'm facing the problem with LMS 2.5. After I reboot the server for maintenance purpose, all the devices in Topology Service > Layer 2 View are "Unreachable" state. I'm just reboot the server and didn't do anything on this LMS installed server. I've been watching for 2 days already, but still "Unreachable". I can see the device status from "Cisco View" and also can "Telnet" to the device. After this problem comes out, I noticed one of my C3550 switch has a "%SNMP-3-AUTHFAIL: Authentication failure for SNMP req from host dec.dec.dec.dec. I also attach the pdshow, ani log and ANIserver log. I really appreciate any help. Thanks all.
ps: I also found "Error in communicating with DCA Server. DCA Server may be down.....Please start the DCA Server and then refresh the page."