Filter
Top Products
Chapter 6
6 - 2
Using Topology load balancing
The Topology load balancing mode is optimal for organizations that have
data centers in more than one country or on more than one continent. The
3-DNS Controller enables topology-based load balancing by resolving DNS
requests to the geographically closest server. The traditional topology load
balancing mode, which provides basic topology mapping functionality, uses
IP subnets of virtual servers and known LDNS servers. This can result in a
very large list of IP subnets to manage when you want to map a specific
geographic region.
To simplify topology load balancing, the 3-DNS Controller contains a
classifier that maps IP addresses to geographic locations. With this
classifier, the 3-DNS Controller resolves DNS requests to the
geographically closest LDNS server at either the country or the continent
level. The system then load balances the request to virtual servers in IP
subnets, wide IP pools, or data centers.
You can set up Topology load balancing either between wide IP pools or
within a wide IP pool. For the example in Figure 6.1, we configure
Topology load balancing between wide IP pools.
Setting up a globally-distributed network
configuration
By going through the following setup tasks, you can configure the 3-DNS
Controller to process requests, using Topology, in a globally-distributed
network. This configuration is based on the following assumptions:
• You have more than one data center.
• You have a 3-DNS Controller in each data center.
• You have BIG-IP systems, or other load balancing hosts, in the data
centers.
• You want to load balance requests to the geographically closest virtual
server.
If you use a CDN for some or all of your content delivery, please refer to
Chapter 7, Configuring a Content Delivery Network, to set up this
configuration.
The following sections describe, in order, the specific configuration tasks
you perform to set up a globally-distributed network. Please review the tasks
before you actually perform them, so that you are familiar with the process.