Author: Nayyar Ahmad
Contact: nayyares *AT* gmail *DOT* com
Dedication: To my pets, boby and tavi.
Some times, we are required to resolve our internal domains on a local nameserver and external (Internet) domains from ISP’s nameserver. There are different solutions to this problem, but in this howto, we are going to solve it through configuring a combination of caching-nameserver and BIND 9.
Theory Behind Caching-Namerserver and BIND 9:
Caching-Nameserver is a type of nameserver that will resolve a web addresses (domain names) from its next or master DNS, and will keep those entries in cache, after first time resolution it will resolve DNS queries locally, untill its TTL (Time To Live) is expired.
BIND 9 is used to resolve domain resolution queries from it own database, as it is SOA (Start Of Authority).
So now it is clear that in our setup the caching-nameserver will be used to resolve domain names externally (internet), while BIND 9 will be used to resolve domain names from our local network (internally).
Now we have caching-nameserver and BIND 9 hammer in our hands, lets start fixing it. 🙂