If you want to resolve both sites I would set the domain name on 192.168.2.0 to lan2 and the 192.168.8.0 to lan8
In 192.168.2.0 in DNS forwardings you add: /lan8/192.168.8.1 this tells the DNS server to ask 192.168.8.1 for *.lan8 domain names.
In 192.168.8.0 you add in DNS forwardings: /lan2/192.168.2.1
Hopefully you get the idea (and hopefully I am right) 