Using TFTP in docker, getting a timeout

Question

I have a tftp server running in a docker container.

I am using this image and I tried different ones: https://hub.docker.com/r/jumanjiman/tftp-hpa/ .

When I try to get a file from the tftp server, it just says: Transfer timed out. Do you guys have an idea? I am on macOs

is the docker container running on your mac or another system? have you verified that it has any network connectivity? — sippybear, Mar 17 '20 at 20:17
The docker container is running on my system. Yes I exposed the port — Lukas Germerott, Mar 18 '20 at 10:24

score 1 · Answer 1 · answered May 30 '20 at 16:00

TFTP is a protocol that uses port 69 when "negotiating/stablishing" a transfer but the actual "data" transfer is carried out on a different ephemeral port. If you exposed only port 69 and the traffic on the ephemeral port range is somehow blocked you will receive a "Transfer timeout error"

score -1 · Answer 2 · answered May 30 '20 at 17:29

-1

If the traffic actually does flow, I’ve seen TFTP implementations that were extremely sensitive to the block size read by the server. Try increasing it if configurable, but keep it a bit below your network’s MTU size (often 1500 bytes)

answered May 30 '20 at 17:29

Mikael H

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Using TFTP in docker, getting a timeout

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