I have been trying to PXE boot a machine for OS installation. A separate computer is running a TFTP server (Netboot.xyz) which I verified that it is working correctly.
On the router (RUTX50) DHCP I successfully set option 67 for setting the boot image, however setting option 66 for the tftp/server-next address, does not have any effect. The IP is always the router IP address instead of the one that is configured.
I tried setting the IP using:
the web interface
change configuration by SSH login
manually start dnsmasq with options on CLI (also SSH login)
At boot of the machine, I see it is trying to boot the image that is configured, but using the IP address of the router instead of the external TFTP server.
Please choose the right category under the required field. The question is related to “Network” category, and the question is posted under “Telematics” category. The concerned Engineer from Network department will address the question once you create a new query.
To help narrow this down, could you please confirm a couple of things:
Can you capture the DHCP exchange during PXE boot (for example using Wireshark or tcpdump) and check what value is being sent for next-server (siaddr) in the DHCPOFFER/DHCPACK?
Is the router currently running its own TFTP service, or only providing DHCP?
Are you configuring option 66 and 67 under the LAN DHCP settings, or using any custom dnsmasq configuration?
What firmware version is currently installed on the RUTX50?
If possible, please also share the relevant DHCP configuration (from the web UI or /etc/config/dhcp). This will help determine whether the router is overriding the TFTP server field internally.
Once we confirm what value is being sent in the DHCP reply, we should be able to identify whether the configuration needs to be adjusted or if the router is forcing the next-server value.
