Configuring dnsmasq with UEFI for PXE.

[Tom Elliott]

@KnightRaven After making the changes to the ltsp.conf file, are you restarting the dnsmasq service?

Making the changes is the “first” part, but the configuration is loaded when the service starts. Any additional changes you make will not take effect until after the service is restarted.

[KnightRaven]

@Tom-Elliott
Alrighty, a new day, another dollar, and fresh eyes.
Yes I have been restarting dnsmasq. Didn’t realize it would use any ltsp file(maybe any file?) in that folder. And so was getting combined info/options. Still wasn’t working for UEFI in proxy mode when I left.
At another location that I will try working on and see what happens now that I know not to leave copies in the dnsmasq.d folder.

[Tom Elliott]

@KnightRaven DNSMasq will use any file within the directory.

So simply copying and maintaining “Backup” files in the directory will not suffice, unfortunately.

[george1421]

Once you get dnsmasq setup and pulling the correct file, and IF it doesn’t work we’ll need to grab a quick pcap file of the dhcp / pxe booting process. The answer will be in the pcap. But lets not go there unless we need to. But the answer is pretty close once you get dnsmasq pulling the proper file.

[KnightRaven]

@george1421
OK, so far it boots legacy and boots UEFI in DHCP(non proxy) mode only. When I leave dnsmasq in proxy mode PXE does not receive anything(no menu) and will just time out to pressing F* key options to reboot.

I tried doing a tcpdump. But not sure what to look for myself. I did see where it was trying to offer the ipxe.efi file. Perhaps you have a way to narrow the results?

[george1421]

If your fog server, target system, and dhcp server on the same subnet? If so lets capture a log of the pxe booting process.

1. install tcpdump on your fog server.
2. Launch tcpdump with the following command sudo tcpdump -w output.pcap port 67 or port 68 or port 69 or port 4011
3. pxe boot your target computer until you get the errir
4. press ctrl-c on the console to stop the tcpdump program
5. you can review it with wireshark or post it here and we will review it.

We really need to see what is going down the network wire during dhcp booting.

[KnightRaven]

@george1421
Our true DHCP server is not on same subnet(it’s located in a whole other building). However my Fog server that also runs dnsmasq as proxy and the test laptop is on the same local switch.
Here is the output…
0_1481909299445_output.pcap

[KnightRaven]

@george1421
here is the ltsp again…
0_1481911611868_ltsp.conf

[KnightRaven]

@george1421
OK another pcap AND the ltsp just in case.

1_1481923279812_output4.pcap 0_1481923279811_ltsp.conf

[Tom Elliott]

@KnightRaven What if you uncomment the “dhcp-no-override” and restart?