The primary purpose of the BIG-IP®
Global Traffic Manager is to help you manage incoming wide IP traffic, and load balance that traffic to the appropriate network resources. However, wide IP traffic is only part of the overall DNS traffic a network must handle. Consequently, typical installations of the Global Traffic Manager involve configuring the system to work in conjunction with existing DNS servers already on the network. F5 Networks recommends that you configure your DNS server to delegate wide IP-related requests to the Global Traffic Manager for name resolution.
To control how the Global Traffic Manager responds to DNS requests, you
must configure a listener. A listener
is a specialized resource that is assigned a specific IP address and 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.
This implementation focuses on 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 delegated zones of www.siterequest.com
, which an existing DNS server manages. The team at SiteRequest has already configured the Global Traffic Manager with two wide IPs, store.wip.siterequest.com
, which correspond to the two web applications.
In order for the Global Traffic Manager to manage the web applications of store.siterequest.com
, you must create the delegated zone on the existing DNS server. Creating a delegated zone typically involves the following tasks:
Again, if you are unfamiliar with how to create these zones, F5 Networks
recommends that you review the 5th edition of DNS & BIND
, available from OReilly®
The final task requires you to set up a listener on the Global Traffic
Manager. A listener
is a specialized resource that you assign a specific IP address and that uses port 53
, the DNS query port. The Global Traffic Manager employs this listener to identify the DNS traffic for which it is responsible. In this implementation, the listener you create is the same as the IP address of the Global Traffic Manager: 192.168.5.17
You now have an implementation of the Global Traffic Manager in which
the existing DNS server manages DNS traffic unless the query is for store.siterequest.com
. When the DNS server receives these queries, it delegates them to the Global Traffic Manager, which then load balances them on the appropriate wide IPs.