Click Devices > Access Gateways > Edit > DNS.
If Access Gateway is a member of a cluster, select the server you want to configure from the list of servers in the Cluster Member field. All changes made to this page apply to the selected server.
Specify the following details:
Server Hostname: Displays the unique host or computer name that you have assigned to Access Gateway machine. If you modify this name, you need to modify the entry for Access Gateway in your DNS server to resolve this new name.
Domain: Specifies the domain name for your network. Your DNS server must be configured to resolve the combination of the server hostname and the domain name to Access Gateway machine. This field assumes you are using dotted names for your machines, such as sales.mytest.com, where sales is the Server Hostname and mytest.com is the Domain.
DNS Server IP Addresses: Displays the IP addresses of the servers on your network that resolve DNS names to IP addresses. You can have up to three servers in the list. If you specified any addresses during installation, they appear in this list. To manage the servers in this list, select one of the following options:
New: To add a server to the list, click this option and specify the IP address of a DNS server.
Delete: To delete a server from the list, select the address of a server, then click this option.
Click OK.
On the Server Configuration page, click OK > Update > OK.