Workaround

I’m not sure what was going wrong with what I was doing initially, but, thanks to @[email protected], as suggested, I disabled the tftp server system service, and, instead, started it with the following command:

sudo in.tftpd -L /srv/tftp --verbose --permissive -s

and it then flashed successfully.

Original Post

cross-posted from: https://sh.itjust.works/post/11735447

I’m trying to flash firmware to a router (Archer C7) using TFTP, but, when the router makes the request for the firmware file over TFTP, the TFTP server responds with the following error

Error code: Access violation (2)
Error message: Only absolute filenames allowed

This is the config for tftpd in /etc/conf.d/tftpd:

TFTP_OPTIONS="-s"
TFTP_DIRECTORY="/srv/tftp"
TFTP_USERNAME="tftp"
TFTP_ADDRESS="192.168.0.66:69"

I have the firmware file in /srv/tftp, and both the firmware file, and /srv/tftp have chmod 777 permissions.

The TFTP server is running on Archlinux, and is installed as tftp-hpa from the arch repos.

If I test as a client, I can get it to download if I specify the full (absolute) path to the file /srv/tftp/filename, so it seems that the config isn’t pointing the server to /srv/tftp as the relative path… How would I go about fixing that?

  • @tapdattl
    2•11 months ago

    I recently ran into the same issue flashing firmware on a Cisco Aironet 3700, the command I ended up using was sudo in.tftpd -L (directory) --verbose --permissive -s

    I was running TFTPD on Fedora 38 on my laptop, though. I’m pretty sure I had the same issue you did, I think changing the command to in.tftpd fixed it, but I could be misremembering as this was about 6 months ago.

    • KalciferOP
      2•11 months ago

      Thank you very much! Your suggested command worked. I still have no idea what was going wrong with what I was initially doing, but at least I have succesfully flashed the firmware. I ran the following command:

      sudo in.tftpd -L /srv/tftp --verbose --permissive -s

      and it succesfully flashed. It was a major relief to see the full data exchange on Wireshark instead of the afformentioned error that I had seen pop up a thousand times.