Check and make sure the McAfee Agent service is running. We have multiple systems that after a reboot the service, even though its set to automatic, will not start. If you manually start it, it runs fine. Very frustrating. (This happens with agents 220.127.116.119 and 18.104.22.168)
What version of the agent? The agent logs will log the communication attempt to the server or agent handler. Then when you get a failure, you need to check the server logs for same time frame of the connection attempt for any errors. There are many reasons for communication failures and without knowing the specific errors, there is no way to give a solution. If you are using the 5.x agent, please read the known issues KB83895.
There are basically 2 kinds of failures:
1. Agent attempts to connect and the server rejects it for some reason or another
2. Agent is not able to reach epo server or agent handler at all
Only the logs will say for sure what the real problem is. There is a log reference guide for epo that is helpful (pd24809) and the 5.x product guide will have log locations for the agent logs.
Agent Version 22.214.171.124
"McAfee Agent Service" dies, it will not synchronize MDE-Users and will not update the DAT-Files.
After starting masvc, it will work again.
The Agent Logs: https://1drv.ms/u/s!AvdVHF4RAwA2wBz26NflilP7O_vw
EEDK -> CMD -> net start masvc
-> Client Task every 15 minutes.