Getting Pi-hole to do reverse lookups
As I was unable to find this anywhere on the web and had to walk back to the solution from dnsmasq I thought that some others may find this interesting.
The problem
Many users of Pi-hole would the built in DHCP server. But for those like me that have a complex (ok its unnecessarily complex) you may want to use a separate DHCP server that would be authoritative for you local lan. But if you do this the Dashboard will now only show IP addresses.
The easy stuff
If the pihole is on the same LAN as all your clients you can simply configure a Conditional Forwarding IP address in Settings -> DNS and uncheck the Never forward reverse lookups for private IP ranges
But if you are like me I want to have separate networks on my lan so this will not resolve the other networks.
Adding additional arpa zones.
If you look at /etc/pihole/setupVars.conf you will find the following line (or similar).
CONDITIONAL_FORWARDING_REVERSE=10.168.192.in-addr.arpa
This will forward all reverse lookups for 192.168.10.0/24 IPs but not any other networks.
So by editing this to server=/168.192.in-addr.arpa/192.168.10.1
This will forward lookups for all 192.168.0.0/16 and for me this covers all of my networks.
Then all you have to do is run a pihole -r and run repair to update dnsmasq.
Hope this helps the next person that runs into this.