This implementation focuses on using a BIG-IP®
Global Traffic Manager system as a load balancer in front of a pool of DNS servers. The Global Traffic Manager checks incoming DNS queries. If the query is for a wide IP, the Global Traffic Manager load balances it to the appropriate resource. Otherwise, the Global Traffic Manager forwards the DNS query to one of the servers in a pool of DNS servers, and that server handles the query as needed.
To control how the Global Traffic Manager responds to DNS requests, you
must configure a listener. A listener
is a specialized resource that you assign to a specific IP address, which uses port 53
, the DNS query port. When traffic is sent to that IP address, the listener alerts the Global Traffic Manager, allowing it to handle the traffic locally or forward the traffic to the appropriate resource.
Once again, for our example we use the fictional company SiteRequest.
SiteRequest recently purchased a Global Traffic Manager to help load balance traffic across two of its web-based applications: store.siterequest.com
. These applications are subdomains of www.siterequest.com
, which is managed by a pool of existing DNS servers. SiteRequest has already configured the Global Traffic Manager with two wide IPs, store.siterequest.com
, which correspond to these two web applications.
For the purposes of this implementation, the IP address of the Global Traffic
Manager is 192.168.5.10
, while the IP addresses of the DNS servers are 10.10.1.1
The first task in this implementation is to configure a pool that contains the
DNS servers to which you want the Global Traffic Manager to load balance DNS traffic.
The next task in this implementation is to configure a listener that listens for
DNS queries and load balances non-wide IP traffic destined for the DNS servers to a member of the pool you created in the previous task.
You now have an implementation of the Global Traffic Manager in which
the Global Traffic Manager receives DNS queries. If the query is for a wide IP, the Global Traffic Manager load balances the request to the appropriate resource. Otherwise, the Global Traffic Manager load balances queries to the pool of DNS servers.