Cliff Hobbs at myITforum.com

[MS KBs] Communication between a System Center Operations Manager 2007 Gateway Server and Management Server fails…

A System Center Operations Manager 2007 Gateway Server may have problems communicating with its Management Server. You may also see the following events on the Gateway Server:

Log Name:      Operations Manager
Source:          OpsMgr Connector
Date:              <date><time>
Event ID:         21016
Task Category: None
Level:              Error
Keywords:        Classic
User:               N/A
Computer:      <gateway-server>
Description:
OpsMgr was unable to set up a communications channel to <gateway-server> and there are no failover hosts.  Communication will resume when <gateway-server> is available and communication from this computer is allowed.

Log Name:      Application
Source:          MsiInstaller
Date:             <date><time>
Event ID:        11707
Task Category: None
Level:             Information
Keywords:      Classic
User:              <user>
Computer:      <gateway-server>
Description:
Product: System Center Operations Manager 2007 R2 Agent -- Installation operation completed successfully.

http://support.microsoft.com/default.aspx?scid=kb;en-us;2004886

Full Title: Communication between a System Center Operations Manager 2007 Gateway Server and Management Server fails when the Agent is installed on the Gateway Server

Read the complete post at http://wmug.co.uk/blogs/cliffs_blog/archive/2009/11/16/ms-kbs-communication-between-a-system-center-operations-manager-2007-gateway-server-and-management-server-fails.aspx