Ubuntu bind slave not updating
If you intend to serve a registered domain name they ensure that your DNS zone is still available even if your primary server is not online.You can even configure BIND9 to be a Caching and Primary Master DNS server simultaneously, a Caching and a Secondary Master server or even a Caching, Primary Master and Secondary Master server.
There are also two other common DNS server setups (used when working with zones for registered domain names), Stealth Primary and Stealth Secondary.Note: There are some issues with this Howto, too numerable to fix quickly, and it requires bringing up to standard. in all other places, the document uses the machine name example ns.I'm mentioning this to help anyone to avoid the unnecessary time trying to resolve their DNS, owing the the inconsistencies in this document, particularly if you're new to DNS configuration. Here it changes to box (I believe the author was simply trying to show that additional computers would be listed, but failed to use a different address for box.I modified the example file to give box an address of 192.168.1.21).Domain Name Service (DNS) is an Internet service that maps IP addresses and fully qualified domain names (FQDN) to one another.These are effectively the same as Primary and Secondary DNS servers, but with a slight organizational difference.
If you configure your registered domain to use A and B as your domain's DNS servers, then C is a Stealth Secondary.
It's still a secondary, but it's not going to be asked about the zone you are serving to the internet from A and B If you configure your registered domain to use B and C as your domain's DNS servers, then A is a stealth primary.
In this way, DNS alleviates the need to remember IP addresses. Ubuntu ships with BIND (Berkley Internet Naming Daemon), the most widely deployed DNS server.
In this configuration BIND9 will find the answer to name queries and remember the answer for the next query. By caching DNS queries, you will reduce bandwidth and (more importantly) latency.
A secondary master DNS server is used to complement a primary master DNS server by serving a copy of the zone(s) configured on the primary server.
Secondary servers are recommended in larger setups.