You want to modify your zone data without restarting the name server.
Make the change to the zone data file. For BIND 9, run:
# rndc reload domain-name-of-zone
For BIND 8, run:
# ndc reload domain-name-of-zone
If you've modified multiple zones, just list them after reload. For example:
# rndc reload foo.example bar.example
Remember to increment the serial number in your zone's SOA record after changing the zone data. The primary master reloads the zone regardless of whether you've incremented the serial number, since the file's modification time has changed, but your zone's slaves only have the serial number to tell them whether the zone has been updated.
Reloading individual zones, as shown above, was introduced in BIND 8.2.1 and again in 9.1.0. With older versions of BIND, just use rndc reload or ndc reload, as appropriate. That takes a little more time, since the name server checks all zone data files to see which have changed.
If you're reloading a zone that exists in multiple views on a BIND 9 name server, specify the view with rndc reload domain-name-of-zone class view. For example:
# rndc reload foo.example in external
Unfortunately, you can't leave out the class, even though you're unlikely ever to reload a non-Internet class zone.
Telling a BIND 9 name server to reload a dynamically updated zone has no effect, since the name server doesn't expect you to update the zone manually. Telling a BIND 8 name server to reload a dynamically updated zone may work -- or you may lose your manual changes. See Section 2.16 for instructions on how to make manual changes to a dynamically updated zone.
Dynamic update is, of course, another way to update zone data without restarting the name server; see Section 5.20 for details.
5.6.4 See Also
Section 2.16, for making manual changes to a dynamically updated zone; Section 5.8, for manually initiating a zone transfer on a slave; Section 5.20 for modifying a zone using dynamic update; and "Controlling the Name Server" in Chapter 7 of DNS and BIND.
BIND Name Server Configuration
BIND Name Server Operations
Delegation and Registration
Interoperability and Upgrading
Resolvers and Programming
Logging and Troubleshooting