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TFTP Client on CISCO 1900 retransmit RRQ

Hello guys,

I have a question about TFTP client implementation on CISCO 1900 routers, I hope someone knows this issue so I can give suitable explanations to my colleagues. To make it simple, I am running a copy tftp run on my router to read a .cfg file stored on a tftpd linux server. I already know the re-transmission issues inherited from the first RFCs but this seems to be another problem. Here is the wireshark capture:


What I can't explain is why the router sends 3 times a new RRQ while he received correctly the last data block (2)  and sent the ack number 2.

Is it related to UDP sockets? Is it simply a CISCO implementation to ensure that the file has been correctly transmitted? in this case, why is it done for small files and not big ones?

Besides, I can't find any way to change/view TFTP client parameters (timemout, block sizes, etc) on the router.

Any help is much appreciated.


-- Slim

  • WAN Routing and Switching
VIP Gold

Wrong forum. The Feedback

Wrong forum. The Feedback Forum is dedicated to discussion about Cisco support forums system itself.

I'm not sure that anyone able to answer your question, this query finds (I'm no such kind of expert).

Also, it's been better to attach Wireshark capture, not static screenshot.