Allow specific protocols(dns, dhcp, http, https) to specific IP/network and Block internal/corp network from guest.
dns server - 8.8.8.8, it could also be any based on the requirement.
dhcp server - 192.168.20.1
http &https - Any network
Guest network - 192.168.10.0/24
Corp Subent 1 - 10.10.10.0/24
Corp Subnet 2 - 172.16.10.0/24
Check Attachment for configuration.
