How to increase maximum connection backlog limit in windows 2008 server
I have a Windows 2008 Server. Its maximum connection backlog limit (TCP) is 200. Is there any way to increase this limit to a higher value – say 1000 or 2000?
In this article you will find description of parameters to change in the registry under this key:
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AFD\Parameters
The relavant values should be these:
- EnableDynamicBacklog (DWORD)
- MinimumDynamicBacklog (DWORD)
- MaximumDynamicBacklog (DWORD)
- DynamicBacklogGrowthDelta (DWORD)
I have tried using different sets of values like
- EnableDynamicBacklog = 1
- MinimumDynamicBacklog = 250
- MaximumDynamicBacklog = 20000
- DynamicBacklogGrowthDelta = 100
and
- EnableDynamicBacklog = 1
- MinimumDynamicBacklog = 20
- MaximumDynamicBacklog = 1000
- DynamicBacklogGrowthDelta = 10
but no matter what I do I am still limited to a backlog of 200 connections. (And yes I have rebooted the server between configuration changes.)
Any ideas?
Solution 1:
Syn Attack protection has been implemented in TCP/IP stack of Vista and later OS. Therefore these registry parameters are no longer relevant.
Please refer to this technet article for more information about Syn Attack protection.