@jamcdonald120 said:
if we assume that the DHCP setting of the router are correct (they worked before) …
I am sure I have heard phrases like this more than a hundred times and it quite often turns out …
Asking the web to see what other things could cause this issue I see that the error message you posted is not quite the same most other people report - which is: PXE-E53: No boot Filename received (see the difference between ‘File’ and ‘Filename’?). Your positive test of trying to load the undionly.kpxe (how do you know your server is using this file and not ipxe.kpxe which we also use sometimes?) binary file makes me believe that your TFTP and the files on it are fine. This would emphasize even more that something is wrong with the DHCP! The message essentially says: “I got an answer from a DHCP server but no information on what file to load for PXE booting”.
You need to understand that DHCP is always a bit of an issue. This is because even if neither you nor any colleague changed the “original” DHCP server you can still run into problems if someone added another DHCP server answering requests in your network.
Please try this: Make one of your clients ready for turn on and PXE boot. Install and run tcpdump - a tool to capture network traffic - on your FOG server.
sudo -i
apt-get install tcpdump
tcpdump -w /tmp/dhcp_traffic.pcap port 67 or port 68 or port 69 or port 4111
Leave that command as is and start up the client till you see the error message on screen. Then stop the tcpdump command (Ctrl-c) and upload that packet dump file (/tmp/dhcp_traffic.pcap) from your server to the forum here.
