1. query your domain
Nslookup yourdomain.com
2. To find all the DNS servers this will resolve the query
set q=any
3.set your secondary server IP as DNS server
Server A.B.C.D
4.now query your domain again
If fails ,
It means your secondary domain doesn't have copies of your
zone
If it is bind server check following on /etc/named.conf
Note: your master server is 192.168.0.1
zone "yourdomain.com" IN {
type slave;
file "/var/named/yourdomain.com.zone";
// allow-update { none; };
allow-transfer { 192.168.0.1/32; };
masters { 192.168.0.1; };
};