ISC DHCP server ignores fixed address specification for Circuit-ID

[Simon Hobson]

codedd713 <codedd713 at protonmail.com> wrote:

> I observed this behavior (below) on ISC DHCP server. Was wondering if this is to be expected or perhaps I overlooked some element.

Yes you've overlooked a critical bit of knowledge - something that's tripped up a few people over the years. All host declarations are global in scope - even when written within a subnet declaration. So the host statement matching the MAC address will always match - even when the client is in the other subnet. This may well prevent the other host declaration from matching - don't know what happens if two host declarations match a client.

Also, I don't know if you can match on that option (circuit ID). AIUI there are only a small number of fields you can match on within a host statement.