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24.1 Legacy Series / Re: KEA DHCP - Reservation DNS Server Override
« on: April 25, 2024, 09:45:02 pm »
Just a for the record.... ISC DHCPv4 and DHCPv6 are still available in OPNsense 24.1.6.
@KeithRBrown with "A feature which I currently use on ISC DHCPv4 is the ability to override the DNS Server setting in a Static Mapping." do you mean the ability to configure a different DNS server for the entire DHCP subnet instead of pointing to the address of the OPNsense instance itself? For instance OPNsense runs with 192.168.1.1 so DHCP clients for the 192.168 subnet get pointed to 192.168.1.1 but configure 192.168.1.200 as the alternative DNS server to be used? That is possible with Kea DHCP already by editing the defined subnet and remove the tick in the box for "Auto collect option data".
OR are you looking for an option to configure different DHCP settings for one or more individual MAC address entries to overrule the settings defined at the subnet level? That finer granularity is NOT available in Kea DHCP (yet?) at the individual client level. To workaround that I have created different subnets for DHCP clients so I can apply differences at that level. Which is something you cannot do with ISC DHCP as that appears to work at the interface level. While thinking about it now, I actually prefer the Kea DHCP approach I am using at the subnet level as I can apply those differences easier for multiple clients in one go.
@KeithRBrown with "A feature which I currently use on ISC DHCPv4 is the ability to override the DNS Server setting in a Static Mapping." do you mean the ability to configure a different DNS server for the entire DHCP subnet instead of pointing to the address of the OPNsense instance itself? For instance OPNsense runs with 192.168.1.1 so DHCP clients for the 192.168 subnet get pointed to 192.168.1.1 but configure 192.168.1.200 as the alternative DNS server to be used? That is possible with Kea DHCP already by editing the defined subnet and remove the tick in the box for "Auto collect option data".
OR are you looking for an option to configure different DHCP settings for one or more individual MAC address entries to overrule the settings defined at the subnet level? That finer granularity is NOT available in Kea DHCP (yet?) at the individual client level. To workaround that I have created different subnets for DHCP clients so I can apply differences at that level. Which is something you cannot do with ISC DHCP as that appears to work at the interface level. While thinking about it now, I actually prefer the Kea DHCP approach I am using at the subnet level as I can apply those differences easier for multiple clients in one go.