Brocade Communications Systems 12.4.00 manual Enabling DNS override, Configuring zones

2 Basic GSLB for IPv6 configuration

Enabling DNS override

DNS override enables you to configure the GSLB ServerIron ADX to "override" the DNS reply for a domain and specify the IP addresses for the domains configured on it. DNS override (when configured in conjunction with DNS cache-proxy) allows the GSLB ServerIron ADX to respond directly to DNS queries using the configured IP lists, without the need for a backend DNS server.

To enable DNS override, use the dns override command. You must enable DNS override to allow the ServerIron ADX to insert the proxy IP address in the DNS reply.

ServerIronADX(config)# gslb policy

ServerIronADX(config-gslb-policy)# dns override

Syntax: [no] dns override

NOTE

Although DNS override is a global parameter. The response to the client contains all the domain IPs configured for the domain. You can enable the active-only option in the policy, in which case the reply contains only the active addresses. Refer to “Configuring an active-only policy” on page 229.

To display the DNS override state, enter the show gslb policy command. The state is shown in the DNS override field. Refer to “Displaying the default GSLB policy” on page 175 for more information.

NOTE

Both DNS cache-proxy and DNS override must be enabled to configure GSLB for IPv6.

Configuring zones

You must specify the DNS zone name and the host information (applications) within each zone for which you want the GSLB ServerIron ADX to provide global server load balancing. There are no defaults for these parameters.

To configure a zone, enter commands such as the following:

ServerIronADX(config)# gslb dns zone-name brocade.com

ServerIronADX(config-gslb-dns-brocade.com)# host-info www http

ServerIronADX(config-gslb-dns-brocade.com)# host-info ftp ftp

This example adds the zone brocade.com and two host names within that zone: www and ftp. The GSLB ServerIron ADX will provide global SLB for these two hosts within the zone.

Syntax: [no] gslb dns zone-name <name>

The <name> parameter specifies the DNS zone name. If you delete a DNS zone (by entering no gslb dns zone-name<name>), the zone and all the host names you associated with the zone are deleted.

Syntax: [no] host-info<host-name> <host-application> <TCP/UDP-port-num>

The <host-name>parameter specifies the host name. You do not need to enter the entire (fully-qualified) host name. Enter only the host portion of the name. For example, if the fully qualified host name is www.brocade.com, do not enter the entire name. Enter only “www”. The rest of the name is already specified by the gslb dns zone-namecommand. You can enter a name up to 32 characters long.

The <host-application>parameter specifies the host application for which you want the GSLB ServerIron ADX to provide global server load balancing. You can specify one of the following:

198	ServerIron ADX Global Server Load Balancing Guide
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