MsExchange Blog Spot Telnet25

June 12, 2012

TMG 121 The semaphore timeout period has expired.

Filed under: General — telnet25 @ 4:38 am


Error Code: 500 Internal Server Error. The semaphore timeout period has expired. (121)

If you are working on TMG server and Exchange 2010 scenario and receiving above errors , verifying couple things may save the day.

Check your static route table and make sure there is no loop causing this issue. Delete all your static route and add them one by one and make sure Static route is persistent and TMG internal NIC properties has these networks


Windows 2008 use Netsh ( route add , windows 2008 may not honor the static route, even the route may seem to be there from GUI)

NetSH Interface ip show route


Lets assume we have two interface


The interface inside =  talk to Active Directory , This interface does not have DGW ( Default Gateway) , hence we need static route to tell the TMG how to reach back to this network.

Outside interface = Talk to Outside  ) This interface has  DGW ( Default Gateway) , okay if the internal DGW is and we are trying to reach out to, then the NetSH command would be as fallows….. ( Replace the IP addresses suits to your own environment)

netsh Interface ipv4 add route "inside" store=persistent


*The netsh command automatically assumes – unless otherwise specified in the command – that the route added is persistent. We added the persistent statement anyways (-:

To delete any static route

netsh interface ipv4 delete route "Internal"

See the Static route

netsh interface ip show route

Reset the Interface ( very powerful)

netsh interface tcp reset 

Oz Casey, Dedeal ( MVP north America)
MCSE 2003, M+, S+, MCDST
Security+, Project +, Server + (Blog) (Blog)


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