Hello @Yong Da Ong ,
Once you have the Log Analytics Agent (OMS Agent) on the Linux Server (Syslog Server) where Syslog messages are forwarded, and if the Agent is connected correctly to the Log Analytics Workspace, then you can configure what Syslog Facilities you want to collect from the connected Agents from the Log Analytics Workspace resource page --> Legacy agents management --> Syslog and add the required Facilities in the collection configuration.
This will instruct all connected Linux Agents to send the required syslog messages to the Log Analytics Workspace:
I hope this helps!
BR,
George