We found something interesting with our network monitoring software - OpManager. Last week one of my colleagues, who was working on a customer's issue found that SNMP requests sent from ManageEngine products did not get any responses. We did all the basic steps - verifying whether SNMP is enabled on the devices, SNMP credentials etc. - and found everything was perfect. We then tried to send SNMP requests from our MIB browser, a SNMP troubleshooting tool, but no luck. The customer had a MIB Browser from another vendor and we tried sending the SNMP requests from that MIB browser and we got the response from the device.  After spending sometime on the issue, we found the SNMP requests sent from OpManager were getting dropped at the server itself (failed to reach the devices).

That reminded us of the few issues we had with the firewall and anitivirus. We checked the firewall and antivirus on the server. Firewall was disabled, but Symantec antivirus was running. Once we stopped the antivirus, we could receive responses from the devices for the SNMP requests sent from OpManager server. We were bewildered, at the same time very eager to know about why SNMP requests sent from ManageEngine applications are blocked, when the same from the other MIB browser could pass through. We analyzed both the MIB Browsers in-depth. The difference was the platform that they were built on. Our's were built on Java, while the other one was built on .Net. We did some quick research and found that antiviruses block SNMP requests when sent from Java based applications.

Have you folks come across the same? Feel free to share your experiences and thoughts.

This is the second time we had an issue with antivirus. The first one was with McAfee. It didn't allow MySQL of OpManager 8 to start. We did some changes in the McAfee policies to get it working. Please check this link if you haven't checked it before. If you face any such issues, try disabling the firewall and anti-virus during startup which should work.

Pravin