Applies To:

Show Versions Show Versions

Manual Chapter: Introducing Global Traffic Manager Components
Manual Chapter
Table of Contents   |   << Previous Chapter   |   Next Chapter >>

For the BIG-IP® Global Traffic Manager system to operate effectively, you need to define the components that make up the segments of your network. These components include physical components, such as data centers and servers, as well as logical components, such as wide IPs, addresses, and pools. By defining these components, you essentially build a network map that the Global Traffic Manager can use to direct DNS traffic to the best available resource.
Once this basic configuration is complete, the Global Traffic Manager has enough information available to begin directing DNS traffic. You can increase the systems capabilities by adding additional network components as appropriate.
Several components within the Global Traffic Managers configuration have direct correlation to a physical location or device on the network. These components include:
Data centers are the top level of your physical network setup. You must configure one data center for each physical location in your global network. When you create a data center in the Global Traffic Manager, you define the servers (Global Traffic Manager systems, Local Traffic Manager systems, Link Controller systems, hosts, and routers) that reside at that location.
A data center can contain any type of server. For example, one data center can contain a Global Traffic Manager and a host, while another might contain two Global Traffic Manager systems and eight Local Traffic Manager systems.
A server is a physical device on which you can configure one or more virtual servers. The servers that you define for the Global Traffic Manager to manage can include both BIG-IP systems and third-party servers, for example, Local Traffic Manager systems and Windows® 2000 Servers.
One server that you must define is the Global Traffic Manager. This places the system on the network map. You can also define Local Traffic Manager systems, and the virtual servers that these servers manage.
A link is a logical representation of a physical device (router) that connects your network to the Internet. You can assign multiple links to each data center by logically attaching links to a collection of servers in order to manage access to your data sources. Configuring links is optional, although they are very useful when determining resource availability.
Servers, excluding Global Traffic Manager systems and Link Controller systems, contain at least one virtual server. A virtual server, in the context of the Global Traffic Manager, is a combination of an IP address and a port number that points to a resource that provides access to an application or data source on your network. In the case of host servers, this IP address and port number likely point to the resource itself. With load balancing systems, such as the Local Traffic Manager, these virtual servers are often proxies that allow the load balancing server to manage the resource request across a multitude of resources. Virtual servers are the ultimate destination for connection requests.
In addition to the physical components of your network, the Global Traffic Manager also handles DNS traffic over logical components. Logical network components consist of network elements that may not represent a physical location or device. These components include:
To communicate with the rest of your network, you must configure the Global Traffic Manager so that it can correctly identify the resolution requests for which it is responsible. A listener is an object that monitors the network for DNS queries, and thus is critical for global traffic management. The listener instructs the system to monitor the network traffic destined for a specific IP address.
In most installations, when you define a listener for the Global Traffic Manager, you use the IP address of the Global Traffic Manager; however, there are many different ways you can configure listeners so that the system handles DNS traffic correctly.
A pool is a collection of virtual servers that can reside on multiple network servers. When you define the virtual servers to which the Global Traffic Manager directs DNS traffic, you combine those virtual servers into pools. You can then configure the Global Traffic Manager to direct traffic to a specific virtual server within a pool, using a specific load balancing method.
You can apply a different set of options to the same resources as a virtual server. When you add a virtual server to a pool, it becomes a pool member to which you can apply monitors, iRules®, and other configuration options.
One of the most common logical components you create in the Global Traffic Manager is a wide IP. A wide IP maps a fully-qualified domain name to one or more pools of virtual servers that host the domains content.
When a local DNS server requests a connection to a specific domain name, the wide IP definition specifies which pools of virtual servers are eligible to answer the request, and which load balancing modes to use in choosing a pool. The Global Traffic Manager then load balances the request across the virtual servers within that pool to resolve the request.
A distributed application is a collection of one or more wide IPs, data centers, and links that serve as a single application to a web site visitor. A distributed application is the highest-level component that the Global Traffic Manager supports. You can configure the Global Traffic Manager so that the availability of distributed applications is dependent on a specific data center, link, or server. For example, if the New York data center goes offline, this information causes the wide IP and its corresponding distributed application to become unavailable. Consequently, the system does not send resolution requests to any of the distributed application resources, until the entire application becomes available again.
The Global Traffic Manager has a search feature that allows you to search for a specific component or group of components that you want to manage or configure. The search feature can be especially useful for companies with large networks that contain numerous physical and logical components as defined earlier in this chapter.
You can find the search feature on the main screen for each type of component. When the main screen opens, an asterisk displays in the box next to the Filter button, and the list of components that displays below the box includes all of the components of that type. You use the search feature to limit the number of components that display in the list.
When you use the search feature, the system always does a wildcard search. For example, when you search for a wide IP, you can use the search criteria www.do, and the system returns wide IPs with names that include those characters, such as www.domain.net and www.domain2.net.
Additionally, you can use wildcard characters in your search criteria; however, in this case, the system tries to match the search pattern exactly. For example, if you search for wide IPs using *www.do, the system does not return the wide IPs www.domain.net and www.domain2.net, because the search pattern has the wildcard character on its left side. The system matches only wide IPs with names ending with www.do.
Note: If you do not specify at least one wildcard character in a search pattern, the Global Traffic Manager automatically adds a wildcard character to each side of the search pattern; therefore, the search patterns www.do and *www.do* return the same results.
Table of Contents   |   << Previous Chapter   |   Next Chapter >>

Was this resource helpful in solving your issue?




NOTE: Please do not provide personal information.



Incorrect answer. Please try again: Please enter the words to the right: Please enter the numbers you hear:

Additional Comments (optional)