Re: I never thought of this scenario

Rich <rich@example.invalid> writes:

And, the protocol "must" be routable:
>
RFC2131: https://www.rfc-editor.org/rfc/rfc2131 - page 6:
>
        DHCP should not require a server on each subnet.  To allow for
        scale and economy, DHCP must work across routers or through the
        intervention of BOOTP relay agents.
>
Note they use "must" above in the statement "DHCP must work across
routers".  Page 4 defines "must" as:
>
        o "MUST"
       
        This word or the adjective "REQUIRED" means that the item is an
        absolute requirement of this specification.

You missed a bit:

   Throughout this document, the words that are used to define the
   significance of particular requirements are capitalized.  These words
                                               ^^^^^^^^^^^
   are:


The ‘must’ in the design goals is not capitalized.

Therefore the RFC explicitly allows for DHCP to be routed.

A protocol is not its design goals. You can’t conclude that a protocol
actually achieves a goal just by looking at the what the goals were. A
good recent example would be SIKE, which totally failed to meet its
design goals.

I don’t personally care how DHCP gets across routers but from a quick
skim it looks like it relies some kind of relay agent. Table 1 or
section 3.1 might be reasonable references.

--
https://www.greenend.org.uk/rjk/