Everyone knows that there are 4 steps to a DHCP handshake.
Everyone talks about DORA (Discover, Offer, Request, Ack) and the "happy path" to getting an address, and this is the most common and important information.
However, there are DHCP options to be considered too. Lots of places talk about the options, their numbers (if relevant), their names, etc., but I am having a hard time finding when they are sent. Some (client options) are clearly sent TO the server, and thus must either be in the Discover or Request cycles, while some are sent FROM the server (service options), and thus must be in the Offer or Ack cycles - but which ones are where?
An example of why this is relevant: I am trying to get a client, that already has an IP address, option 119 (domain-search), and I need to know if I can just add the option and it will work on the next [existing] Request-Ack cycle, or do I need to force that client through a full DORA again? RFC3397 doesn't seem to say anything on it.
This may seem silly for just one client, but when there are loaded networks of production clients, and lots of options to choose from and figure out, it gets messy. Is it always the same for all options? If so, where does it happen? and if not, is there a listing of which options are sent when?
