I'm trying to transfer a file using the Free TFTP tool, but the client/server are trying to talk on High Ports rather than UDP-69.
For this internal-to-external network flow, I'm only allowed to open UDP-69. Any suggestions?
Data transfer is initiated on port 69, but the data transfer ports are chosen independently by the sender and receiver during initialization of the connection. The ports are chosen at random according to the parameters of the networking stack, typically from the range of Ephemeral ports.
See this link for information on Ephemeral ports:
You will need to keep the Ephemeral port range open.