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Control center cannot communicate with Messaging Gateway scanner


Article ID: 170788


Updated On:


Messaging Gateway


The Messaging Gateway (SMG) control center is unable to communicate with the SMG scanner resulting in a number of potential issues:

  • Message audit log queries fail and / or are delayed or spin indefinitely.
  • Cannot propagate configuration changes to scanners
  • Unable to view Message Queues


2018-01-09T21:41:13+05:30 (ERROR:2422.54671328): [33048] Error creating new connection: Unknown error 336150661.


Jan 09 2018 21:41:13 [BrightmailScheduler_Worker-33] [ScriptHelper] ERROR - The Agent running on is temporarily unreachable. Please check the specified host. ; nested exception is: Connection reset

Running netstat on the SMG scanner when it is in this state will also show a number of connections in the SYN_RECV state indicating that the TCP connections are only half open:

smg [10.7.5-4]> netstat -tn | grep 41002
tcp        0      0   SYN_RECV
tcp        0      0       SYN_RECV
tcp        0      0       SYN_RECV
tcp        0      0       SYN_RECV
tcp        0      0       SYN_RECV
tcp        0      0       SYN_RECV
tcp        0      0   SYN_RECV

Packet captures of connections to the affected SMG scanner also show retransmissions of the SYN-ACK indicating that on the scanner the TCP connection is only half open:


Network security scanners can, over time, cause the agent service on Messaging Gateway to become unresponsive. 


The workaround is to restart the agent service on each SMG scanner, one at a time. This should alleviate the issue temporarily.

On the command line run "service agent restart".

This issue will be addressed with a future release but until then it's best to exempt port 41002 on the Messaging Gateway from internal port scans.