Hey BW447 so it sounds like all of the Layer 2 guest VLANs will be tagged all the way back to the core correct. At that point will you have the IP addresses on the core switch?
Your ACL looks correct you will need to add another one to allow the unicast DHCP offer to get back to the host using port 68 I think.
You could then put an entry to add a redirect statement to forward
"redirect ipv4"
"addr—Forwards the packet to the specified IPv4 address (BlackDiamond X8"
"series switches, BlackDiamond 8000 c-, e-, xl-, and xm-series modules, and Summit family switches"
"only)."
Redirecting Packets
Packets are forwarded to the IPv4 address specified, without modifying the IP header (except the TTL is decremented and the IP checksum is updated). The IPv4 address must be in the IP ARP cache, otherwise the packet is forwarded normally. Only fast path traffic can be redirected. This capability can be used to implement Policy-Based Routing.
Would that help?
P