How to configure Bind as a Caching or Forwarding DNS Server on Ubuntu 14.04
It is helpful for you to familiarize yourself first with the different types of DNS servers before deciding on which DNS configuration to adopt.
Types of DNS Servers
You can configure Bind9 DNS Server as either a Cashing or Forwarding DNS Server. Bind is an open source software that makes it possible for internet users to publish their Domain Name System (DNS) information on the internet, and to help them resolve their queries.
To achieve either of these configurations, two computers must be used (and one of these, at least, should be an Ubuntu 14.04 Server). As shown below, one of the two computers will be configured as the client while the other functions as the DNS server.
How to configure Bind9 as A Caching DNS Server
These are the procedures you must follow in order to configure Bind9 DNS server into a Cashing DNS server:
- First, install Bind on the DNS server
- Set up an access control list, ACL
- Create a label for the ACL group
- Within the group, list the IP addresses that should be allowed to use this DNS Server
- Having created an ACL list of clients that this Server will resolve queries for
- The recursive service and other ACL specifications are configured—since there is no concern about authoritative-only server in this condition, the references used to describe the nature of the recursion and caching will define the effectiveness of the Bind9 DNS server
- Once the configuration has been completed, save and close the file
- In case you realize that you are not satisfied with the specifications in the configured Bind9 DNS server, you can restart and start the processes all over again.
- How to configure Bind9 as A Forwarding DNS Server
- Outlined below are the procedures required for configuring Bind9 as a Forwarding DNS Server.
- You can start this process from where we stopped above, using the already configured Caching DNS Server.
- Use the same ACL list to restrict the server only to a specific list of clients
- Change the configuration so that the server will no longer handle and provide solutions to recursive queries
- Set up caching servers to forward the queries to
- Then create a block referred to as “forwarders”, which contain the IP addresses of recursive name servers that the requests or queries will be forwarded to
- You can use Google’s public DNS server for this purpose; that is, as the cashing DNS servers
- Configure that the server only forwards requests to the cashing DNS servers and does not attempt to resolve the queries itself
- Once you have completed this configuration, safe and close the files
After setting up the servers as either a Cashing DNS server or a Forwarding DNS server, go ahead and tweak your devices’ operating systems. This step is essential because you should point the servers to the new Bind9 DNS servers so that problem resolution can take place within the system. If you neglected this step, it may be impossible for the device to point to the new nameservers and complete the required assignment of resolving or forwarding the queries.