Getting Timeouts on TFTP

  • Thread starter Thread starter GeekThug
  • Start date Start date
G

GeekThug

I have installed tftpd.exe as a service on XPE and added the correct
registry setting for the directory. I am able to successfully transmit
very small files but any thing close to a MB makes TFTP timeout. What
do I do? I can not find any documentation on this, any help would be
great.

By the way, I know there are a lot of freeware programs that could be
used, but the licensing for them stop me from using them on our product
so I am trying to use Microsoft's tftpd.exe service.
 
Hello,

I dont know much about tftpd.exe right off the top of my head, but all i can
tell you is that TFTP, which was the predecessor of FTP, was designed to
upload/download small files. Do check the documentation which came with your
TFTP program to verify the size of the files that can be transmitted.

--
Anando
Microsoft MVP- Windows Shell/User
Microsoft Certified Professional
http://www.microsoft.com/mvp
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Folder customizations
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Max size of a tftp datagram is indeed fitting in 2 byte, which gives you around or a little bit less than 65535 datagrams in a file
transfer.
That gives you 32Mb max file size to transfer. This is assuming the block size used is 512 bytes and this is what has been
implemented in MS TFTP for 2k. I don't know if Microsoft has implemented the blocksize option in XP's version (rfc1783) but I failed
to find any related tftpd parameters to control in registry.

In any case, TFTP was developed for transferring small files (bootstrap code), not large files. It may be possible to transfer Mb
and more files over TFTP but it may not be reliable transport for this and on bad networks it may often fail.

IIRC, the max timeout for TFTP UDP datagram is about 10 sec on XP. If you monitor your client/server communications (use Ethereal or
MS Network Monitor and watch on UDP packets) you can see how long it takes to deliver the packets and then you'd know whether it is
TFTP service failure or the network is bad.

Btw, tftpd service is supposed to log error info in to the Event Log. You may want to check it out there.

Another thing to keep in mind when using TFTP. It is an insecure protocol. If your device is network enabled, TFTP service may be a
big hole into the system.
 
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