CSS TFTP Keepalive

[G.greb]

We want to set up a keepalive for a TFTP server. Is it possible to build a script for TFTP? Has someboy an idea to solve this problem? We tried to fetch a file from the server. The server is answereing but because of a differrent source port the CSS send a port unreachable back to the server.

[seilsz]

The CSS scripting functionality is expecting a response from the server using the same source port it sent the request on (udp/69 in the case of tftp).

Unfortunately, you are basically stuck with using icmp keepalives for tftp hosts.

~Zach

[davekbell]

I'd recommend using a TCP keepalive to the TFTP port on the server. If you use an icmp keepalive this will only give you a view as to whether the server is up as opposed to TFTP service on the server.

[Zach Seils]

Most tftp servers I've worked with only start the listener for the udp protocol. Ex:

seils-osx:~ seils$ netstat -an | grep *.69

udp4 0 0 *.69 *.*

seils-osx:~ seils$

Not sure if anyone has a tftp implemtation that runs over tcp. I guess you could start a listener on that tcp port, but that still wouldn't give you a true picture of the availability of the (udp) tftp service.

~Zach