Debugging DHCP relay with netboot

I've got a problem - Hiawei HG8245H router that doesn't forward DHCP packets. https://forums.whirlpool.net.au/archive/2281094 explains it well.

My network card doesn't event get IP from switch's DHCP server and I want to understand why. Is it because Huawei drops DHCPDISCOVERY with Option 60 set. Or is it because my network card expects something different. I would like to debug it with netboot utility.

Even it DHCP Relay option in my switch does not work, there is still a menu with DHCP options and I'd like to try setting them as if the router supports PXE.

Checking router.

[ ] send standard DHCPDISCOVERY request and check that standard DHCPDISCOVERY reply is received (no option set)
[ ] send DHCPDISCOVERY+PXE request and check what kind of DHCPDISCOVERY reply is returned
[ ] add Options 60 to router (no idea what the value should be) and repeat DHCPDISCOVERY and DHCPDISCOVERY+PXE to heck what kind of DHCPDISCOVERY reply is returned see if there is any difference from expected packets. For these tests it would be nice to automate what is expected.

Checking client.

[ ] wait for DHCPDISCOVERY+PXE request and check the differences from standard DHCPDISCOVERY reply - show if there any anomalies like options and show their numbers and values in hex and human readable form
[ ] reconstruct reply from DHCPDISCOVERY+PXE and send it again

It is just a start, and maybe I will be able to trick the router into booting it further.

danderson / netboot

Debugging DHCP relay with netboot #71