How to access DHCP option 43 on client side

rksyeung · 05-09-2020, 06:48 PM

Option 43 contains vendor specific information. I'm trying to extract information passed in from server on my client (either dhclient, udhcpc).

I've heuristically experimented with various parameter names, but none of them produces anything. Does anyone know how this could be done?

Thanks,
Raymond

shruggy · 05-10-2020, 03:11 PM

Does something like this inside dhclient-script work?

Code:

[ "$reason" = "BOUND" ] && echo $new_vendor_encapsulated_options $new_vivso $new_dhcp6.vendor_opts

Pay attention to the prefix new_ and underscores (_) rather than dashes (-) in the variable names. They must be defined on server with dashes and without the new_ prefix though.

rksyeung · 05-10-2020, 04:12 PM

Quote:

Originally Posted by shruggy

Does something like this inside dhclient-script work?

Code:

[ "$reason" = "BOUND" ] && echo $new_vendor_encapsulated_options $new_vivso $new_dhcp6.vendor_opts

Pay attention to the prefix new_ and underscores (_) rather than dashes (-) in the variable names. They must be defined on server with dashes and without the new_ prefix though.

Thanks shruggy. I found my answer eventually, consistent with yours. I should have asked here earlier.
What I eventually did was to download the source code, and did some grep for "vendor". I ended up finding a look-up table mapping strings to 43.