How to get primary DNS to syncronize with secondary DNS

[Brian Guild]

Guys,

I have two dns servers currently, dns1.body1.com and dns2.body1.com.  You
will see a paste of one of my zones below.  What statements should I add to
ensure that when I update my primary DNS server, my secondary DNS server
will syncronize with it and receive the changes?  Currently, I manually
create the zones on both servers and I would assume I am doing this
incorrectly.

Thanks,

Brian

$ttl 38400
testdomain.com.	IN	SOA	dns1.body1.com. brian.body1.com. (
			1016819849
			10800
			3600
			604800
			38400 )
testdomain.com.	IN	NS	dns1.body1.com.
blah.testdomain.com.	IN	A	192.168.0.2
blah2.testdomain.com.	IN	A	192.168.0.3
blah3.testdomain.com.	IN	A	192.168.0.4
mail.testdomain.com.	IN	MX	1 192.168.0.5
blah4.testdomain.com.	IN	A	192.168.0.10

Brian Guild
Network Manager
Body1, Inc.
Business: 617-576-9400
Fax: 617-576-9430
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