In order to make changes to your DNS system run by ISC BIND server:
Edit your zone files. Make whatever changes you were going to and do not forget to update the zone serial number. Without updating the serial number your changes will not be applied. Usually the serial number is made with following pattern
YYYYMMDD00 (where last to digits increment if you change the zone multiple times in one day). In this way it also serves you as a reminder when last change to this zone was made.
Issue a DNS server reload command -
service bind9 reload (for Debian/Ubuntu). This will cause all config changes and zone files changes to be applied. Upon receiving this command the BIND server will also notify all secondary DNS servers (if appropriate configuration was made) about the fact that change was made so that they can transfer zone in order to stay up to date.
You can use
host commands to debug DNS. Issue a direct DNS query to your primary and secondary server in order to see that changes have been applied:
dig hostname.domain @IP-ADDRESS
nslookup hostname.domain IP-ADDRESS
host hostname.domain IP-ADDRESS
hostname.domain is the DNS record that was changed and
IP-ADDRESS is the IP address of your DNS server (primary or secondary).
If everything went OK you should be able to see new address in the response from your servers.
After some time (depending on your zone cache and TTL settings) these changes will be propagated to the global DNS system. You can use same tools in order to query for example Google public DNS servers (
188.8.131.52) and see if your change was successfully propagated (or not yet).
Regarding changes to the authoritative DNS server's IP addresses:
If you are updating the domain's authoritative servers addresses (NS records) you should make this change known to your domain registrar. Usually it can be done in the on-line control panel provided by the registrar. Your registrar may decide to test new servers for compliance to the DNS standards before applying the change. While it is done automatically it still could take some time.