Complete the following steps to set up GSLB from a DNS perspective when the NetScaler is the authority for the GSLB zone:

1. On the NetScaler, create an ADNS service under Load Balancing/Services.

2. Create an Start Of Authority (SOA) record to make the NetScaler authoritative for the GSLB domain. This can be found under DNS/Records. Use the FQDN for the GSLB domain.

3. Make an Address Record to translate the FQDN of the SOA record to the IP of the ADNS service.

4. On the public DNS servers, you will need a NS record for the FQDN for the GSLB virtual server. You will also need an A record to translate the FQDN to the IP for the ADNS service of the NetScaler. This will likely be an IP that is NAT translated to the ADNS service IP.

5. From the Active Directory domain, use the delegation wizard to delegate the DNS for the GSLB domain to the ADNS service of the NetScaler. This will cause queries for the GLSB domain to go to the NetScaler for an official A record of the load balancer to be used for access.

Citrix Documentation - Configuring the NetScaler as an ADNS Server