All posts tagged tftp

I’ve ran in to the mentioned issue yesterday, our WDS stopped working just out of the blue. To make it more convenient , only few days after i experimented with PxeLinux one the WDS…

TFTP open timeout

After some googleing it turns out that culprit is the DNS server role located on the same box. Apparently DNS server is randomly allocating ports (2500 of them) in the range of 49152-65535 which can overlap with WDS range, which by default operates from 64001 to 65000.

On Server 2008 R2, the simple solution is to change dword value of “UdpPortPolicy” to 0 – located in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\WDSServer\Parameters.
Which will make WDS server check if the port is already in use before trying to use it.

There is no “UdpPortPolicy” parameter on Windows Server 2008, so the solution would be to broaden the port range of WDS server. You could do it through Server manager, under network properties of WDS server, or by command prompt
wdsutil /set-Server /Transport /StartPort:50000 /EndPort:65000

Microsoft KB article for more info: