do not respond to DHCPINFORM requests

[Randall C Grimshaw]

The goal is to overcome a bug in dhcp where clients requesting DHCPINFORM information as a followup to a lease, will receive the incorrect DNS configuration in subnets with 'custom' configurations.

The cause is that the DNS information is originally assigned by subnet (or group) and DHCPINFORM responses are only aware of the GLOBAL DEFAULT.

I do not believe that there is any valid DHCPINFORM data for these 'custom' subnets. As I was starting my preliminary code hacking session with the intention of disabling DHCPINFORM responses, I tripped over this section in the existing code that says:

 /* We don't respond to DHCPINFORM packets if we're not authoritative... */

At minimum this implies that if the authoritative statement is not configured as a global and surgically applied the 'non-custom' subnets, that the desired behavior will result for the 'custom' subnets (albeit non-authoritatively).

The caveat that I need to know is... what are the caveats? what can I expect to happen? (or not happen?). Are there clients (currently please - not looking for historical anecdotes) that will not accept leased addresses from non-authoritative servers? Any other 'gotchas'?

Thank you for your assistance in brainstorming a solution to this issue.

Randy Grimshaw