We installed Linux agent in DMZ - we already have quite a lot of them in DMZ - opened all necessary ports (2217-2220 and 2300).
The agent started properly and signed in to Automation Engine properly, but then loses connection.
20210112/080406.633 - U02000073 Connection to system 'AUTOMIC' via CP Server '' successfully established.
20210112/080406.634 - U02000010 Connection to Server 'AUTOMIC#CP001(s=10,ID=3)' terminated.
Release : 12.3
Component : AUTOMATION ENGINE
Created a special UC_HOSTCHAR_PAYARA HOST-VARIABLE and attached it to server XXXXX
In that HOSTCHAR defined KEEP_ALIVE = 60 and RECONNECT_TIME = 15.
Now the agent connection is stable.