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Archived Manual Chapter: 3-DNS Admin Guide, v4.5:Essential Configuration Tasks
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5

Essential Configuration Tasks


Reviewing the configuration tasks

Once you have completed the Setup utility, you set up the network and load balancing aspects of the 3-DNS Controller. The 3-DNS Controller has three essential configuration tasks that all users must complete, regardless of the chosen load balancing solution.

  • Configure the physical aspects of your load balancing network, which includes the following:

    • Data centers
    • Data center servers and their virtual servers
    • Communications between the 3-DNS Controller and other servers
    • 3-DNS synchronization (if you have more than one 3-DNS Controller in your network)
  • Configure the logical aspects of your load balancing network, including wide IPs and pools
  • Configure the global load balancing modes and global variables

Setting up a basic configuration

Each 3-DNS Controller in the network setup must have information regarding which data center houses specific servers, and with which other 3-DNS Controllers it can share configuration and load balancing information. A basic network setup includes data centers, servers, and one sync group. Once you have the basic network components configured on your 3-DNS Controller, you can set up the wide IPs you need for managing your load balancing. We recommend that you review the load balancing solutions in the remaining chapters of this guide before you configure the wide IPs.

The following sections describe the various elements of a basic network:

  • Data centers
    Data centers are the top level of your network setup. We recommend that you configure one data center for each physical location in your global network. The data center element of your configuration defines the servers (3-DNS Controllers, BIG-IP systems, EDGE-FX systems, hosts, and routers) that reside at that location.

    A data center can contain any type of server. For example, in Figure 5.1 , the Tokyo data center contains a 3-DNS Controller and a host, while the New York and Los Angeles data centers contain 3-DNS Controllers and BIG-IP systems.

    For information about configuring data centers, see Setting up a data center .
  • Servers
    The data center servers that you define in the network setup include 3-DNS Controllers, BIG-IP systems, EDGE-FX systems, hosts, and routers. You define the 3-DNS Controllers that manage load balancing to the BIG-IP systems, EDGE-FX systems, and hosts, and you also define the virtual servers that are managed by the servers. Virtual servers are the ultimate destination for connection requests.

    For information about configuring servers, see Setting up servers .
  • Sync groups
    Sync groups contain only 3-DNS Controllers. When setting up a sync group, you define which 3-DNS Controllers have the same configuration. In most cases, you should define all 3-DNS Controllers as part of the same sync group.

    For information about configuring sync groups, see Working with sync groups .
  • Wide IPs
    After you define virtual servers for your BIG-IP systems, EDGE-FX systems, and hosts, you need to define wide IPs to specify how connections are distributed among the virtual servers. A wide IP maps a domain name to a pool of virtual servers, and it specifies the load balancing modes that the 3-DNS Controller uses to choose a virtual server from the pool.

    When a local DNS server requests a connection to a specific domain name, the wide IP definition specifies which virtual servers are eligible to answer the request, and which load balancing modes to use in choosing a virtual server to resolve the request.

    For information about configuring wide IPs and choosing load balancing modes, please refer to Chapter 2, Load Balancing , in the 3-DNS Reference Guide.
  • Global variables
    You can configure global variables that apply to all servers and wide IPs in your network. However, the default values of the global variables work well for most situations, so configuring global variables is optional.

    For information about configuring global variables, see Configuring global variables .

Setting up a data center

The first step in configuring your 3-DNS network is to create data centers. A data center defines the group of 3-DNS Controllers, BIG-IP systems, EDGE-FX systems, and host systems that reside in a single physical location. For each data center that contains a 3-DNS Controller or a BIG-IP system, you can also define a router. Figure 5.1 shows an example of a data center.

The advantage of grouping all systems from a single physical location into one data center in the configuration is to allow path information collected by one server to be shared with all other servers in the data center. The 3-DNS Controller uses the big3d agent to collect path and metrics information about the other servers, and their virtual servers, in the data center. The 3-DNS Controller then applies path metrics results to all the virtual servers in the data center when making load balancing decisions.

Note


You must configure at least one data center before you can add servers to the 3-DNS configuration.

Figure 5.1 Example of a multiple data center setup

When you add servers to the network setup, you assign the servers to the appropriate data centers.

To configure a data center using the Configuration utility
  1. In the navigation pane, click Data Centers.
  2. On the toolbar, click Add Data Center.
    The Add New Data Center screen opens.
  3. Add the new data center settings. For help on defining data centers, click Help on the toolbar.
    The data center is added to your configuration.
  4. Repeat this process for each data center in your network.

Note


To configure a data center from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Setting up servers

There are five types of servers you can configure on a 3-DNS Controller: 3-DNS Controllers, BIG-IP systems, EDGE-FX systems, hosts, and routers. At the minimum, your network includes one 3-DNS Controller, and at least one server (BIG-IP system, EDGE-FX system, or host) that it manages.

This section describes how to set up each server type (3-DNS Controller, BIG-IP system, EDGE-FX system, host, and router) that makes up your network. The setup procedures here assume that the servers are up and running in the network, and that they already have virtual servers defined (if the server manages virtual servers). Note that 3-DNS Controllers and routers do not manage virtual servers.

If you are adding a BIG-IP Link Controller to the 3-DNS configuration, you add the Link Controller as a BIG-IP system. If you want the 3-DNS Controller to be aware of and manage the links on the Link Controller, then you add the Link Controller as a 3-DNS system, also.

Defining 3-DNS Controllers

The purpose of defining a 3-DNS Controller in the configuration is to establish in which data center the 3-DNS Controller resides and, if necessary, to change big3d agent settings. Before you add other 3-DNS Controllers to the configuration, you should add the 3-DNS Controller you are configuring to its own configuration. By adding any additional 3-DNS Controllers to the configuration, you make those 3-DNS Controllers available so that you can add them to a sync group.

Note


Please review Chapter 10, Adding a 3-DNS Controller to an Existing Network , if you are configuring more than one 3-DNS Controller in your network.
To define a 3-DNS Controller using the Configuration utility
  1. In the navigation pane, expand the Servers item, then click 3-DNS.
  2. On the toolbar, click Add 3-DNS.
    The Add New 3-DNS screen opens.
  3. Add the new 3-DNS settings. For help on defining 3-DNS Controllers, click Help on the toolbar.
    The 3-DNS Controller is added to your configuration.

Note


For details on how to configure a 3-DNS Controller from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Defining BIG-IP systems

A BIG-IP system can be any of the following: an IP Application Switch, a Controller, a Cache Controller, a FireGuard Load Balancer, an e-Commerce Controller, or a Link Controller.

Before you define any BIG-IP systems in the configuration, you should have the following information:

  • The self IP addresses and translations of the BIG-IP system's interfaces
  • The IP address and service name or port number of each virtual server managed by the BIG-IP system, only if you do not want to use auto-configuration to discover the BIG-IP system's virtual servers
To define a BIG-IP system using the Configuration utility
  1. In the navigation pane, expand the Servers item, and then click BIG-IP.
  2. On the toolbar, click Add BIG-IP .
    The Add New BIG-IP screen opens.
  3. Add the new BIG-IP system settings. Note that if you want the 3-DNS Controller to discover the BIG-IP system's virtual servers, select ON for the Discovery setting.(For help on defining BIG-IP systems, click Help on the toolbar.)
  4. Click Add when you have finished configuring the initial settings for the BIG-IP system.
    The controller adds the BIG-IP system information to the configuration.
Auto-configuration collects the virtual server information for any BIG-IP systems you have in your network, if you turn on Discovery when you add the BIG-IP system to the configuration. For more information about auto-configuration, see Overview of auto-configuration .

If you do not turn on Discovery when you add the BIG-IP system to the configuration (in step 3, preceding), then use the following procedure to add virtual servers to the BIG-IP system definition.

To add virtual servers using the Configuration utility
  1. In the navigation pane, expand the Servers item, and then click BIG-IP.
  2. In the table, find the BIG-IP system that you just added.
  3. Click the entry in its BIG-IP Virtual Servers column.
  4. On the toolbar, click Add Virtual Server.
    The Add Virtual Server to BIG-IP screen opens.
  5. Add the new virtual server settings. For help on adding virtual servers, click Help on the toolbar.

    Repeat this process for each virtual server you want to add to this BIG-IP system.

Note


For details on how to configure a BIG-IP system from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Defining a BIG-IP system with the 3-DNS module

In the 3-DNS configuration, you treat the BIG-IP system and the 3-DNS Controller module as if they were separate devices. You can add the two server types either by using the Configuration utility or by editing the wideip.conf file. The following instructions describe how to add a BIG-IP system with the 3-DNS Controller module, with the name combo.siterequest.net and the IP address 192.168.100.100, to the configuration.

Before you define a BIG-IP system with the 3-DNS Controller module in the 3-DNS configuration, you should have the following information:

  • The name and IP address of the BIG-IP system
  • The name and IP address of the 3-DNS Controller
To add a BIG-IP system with the 3-DNS Controller module using the Configuration utility
  1. In the navigation pane, expand the Servers item, and then click BIG-IP.
    The BIG-IP List screen opens.
  2. On the toolbar, click Add BIG-IP.
    The Add BIG-IP screen opens.
  3. In the BIG-IP Name box, type combo.siterequest.net.
  4. In the BIG-IP IP Address box, type 192.168.100.100.
  5. Add the rest of the settings as needed.

    Note: When you have finished defining the BIG-IP system, you can add the 3-DNS Controller module to the configuration.

  6. In the navigation pane, expand the Servers item, and then click 3-DNS.
    The 3-DNS List screen opens.
  7. On the toolbar, click Add 3-DNS.
    The Add 3-DNS screen opens.
  8. In the 3-DNS Name box, type combo.siterequest.net.
  9. In the 3-DNS IP Address box, type 192.168.100.100.
  10. Add the rest of the settings as needed.

Note


For details on how to configure a BIG-IP system with the 3-DNS Controller module from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Defining a router

Routers do not manage virtual servers, rather they manage the links to the Internet for your network. Before you define a router in the 3-DNS configuration, you should have the following information:

  • The name of the router
  • The IP address of the router (this is the gateway IP address)
  • The IP addresses of the links that the router manages

Note


If you have a Link Controller or BIG-IP system in your network, the auto-configuration process adds the routers to the configuration for you. Note, however, that for BIG-IP systems, auto-configuration adds only one router per data center. Use the following procedure only if you have auto-configuration turned off.
To define a router using the Configuration utility
  1. In the navigation pane, expand the Servers item, then click Routers.
  2. On the toolbar, click Add Router.
    The Add New Router screen opens.
  3. Add the new router settings. For help on defining a router, click Help on the toolbar.

Note


For details on how to configure a router from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Defining EDGE-FX systems

An EDGE-FX system can be either an EDGE-FX Cache, or a GLOBAL-SITE Controller. Before you define any EDGE-FX systems, you should have the following information:

  • The IP address of the system itself
  • The IP address and service name or port number of each virtual server managed by an EDGE-FX Cache

Auto-configuration automatically collects the virtual server configuration information for any EDGE-FX systems you may have in your network. For more information about auto-configuration, see Overview of auto-configuration .

To define an EDGE-FX system using the Configuration utility
  1. In the navigation pane, expand the Servers item, then click EDGE-FX.
  2. On the toolbar, click Add EDGE-FX.
    The Add New EDGE-FX screen opens.
  3. Add the new EDGE-FX system settings. Note that if you want the 3-DNS Controller to discover the EDGE-FX system's virtual servers, select ON for the Discovery setting. (For help on defining EDGE-FX systems, click Help on the toolbar.)
  4. Click Add when you have finished configuring the initial settings for the EDGE-FX system.
    The controller adds the EDGE-FX system information to the configuration.

Auto-configuration collects the virtual server information for any EDGE-FX systems you have in your network, if you turn on Discovery when you add the EDGE-FX system to the configuration. For more information about auto-configuration, see Overview of auto-configuration .

If you do not turn on Discovery when you add the EDGE-FX system to the configuration, then use the following procedure to add virtual servers to the EDGE-FX definition in the configuration.

To add virtual servers using the Configuration utility
  1. In the navigation pane, click Servers, then click EDGE-FX.
  2. In the table, find the EDGE-FX system that you just added.
  3. Click the entry in its EDGE-FX Virtual Servers column.
  4. On the toolbar, click Add Virtual Server.
    The Add Virtual Server to EDGE-FX screen opens.
  5. Add the new virtual server settings. For help on adding virtual servers, click Help on the toolbar.

Repeat this process for each virtual server you want to add. Note that GLOBAL-SITE Controllers do not manage virtual servers.

Note


For details on how to configure an EDGE-FX system from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Defining host servers

A host is an individual network server or server array controller other than a 3-DNS Controller, BIG-IP system, EDGE-FX Cache, GLOBAL-SITE Controller, or router. Before configuring a host, you should have the following information:

  • Address information
    The IP address and service name or port number of each virtual server to be managed by the host.
  • SNMP information for host probing
    To implement host probing and to collect performance metrics, you must specify SNMP agent settings after you define the host server. The settings you specify include the type and version of SNMP agent that runs on the host, the community string, and the number of communication attempts that you want the big3d agent to make while gathering host metrics. SNMP agent settings for hosts are described in Configuring host SNMP settings .

Note


To fully configure host probing, you must configure the SNMP agent settings in the host definition as previously described, set up the big3d agents to run SNMP factories, and configure the SNMP agents on the hosts themselves. For details, please refer to Chapter 5, Probing and Metrics Collection, in the 3-DNS Reference Guide.

Auto-configuration automatically collects the virtual server configuration information for any load-balancing hosts you may have in your network (with the exception of Cisco® LocalDirectors). For more information about auto-configuration, see Overview of auto-configuration .

To define a host using the Configuration utility
  1. In the navigation pane, expand the Servers item, and then click Host.
  2. On the toolbar, click Add Host.
    The Add New Host screen opens
  3. Add the new host settings. Note that if you want the 3-DNS Controller to discover the host's virtual servers, select ON for the Discovery setting. (For help on defining hosts, click Help on the toolbar.)
  4. Click Add when you have finished configuring the initial settings for the host.
    The controller adds the host information to the configuration.

    Auto-configuration collects the virtual server information for any host systems you have in your network, if you turn on Discovery when you add the host to the configuration. For more information about auto-configuration, see Overview of auto-configuration .

    If you do not turn on Discovery (step 3, in previous procedure) when you add the host to the configuration, then use the following procedure to add virtual servers to the host definition.

To add more virtual servers using the Configuration utility
  1. In the navigation pane, click Host.
  2. In the table, find the host that you just added, and click the entry in its Host Virtual Servers column.
  3. On the toolbar, click Add Host Virtual Server.
    The Add Virtual Server to Host screen opens.
  4. Add the new virtual server settings. For help on adding virtual servers, click Help on the toolbar.

    Repeat this process for each virtual server you want to add to this host.

Note


For details on how to configure a host from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Configuring host SNMP settings

After defining a host server, you need to configure its SNMP settings if you want to use SNMP host probing. Remember that you must first set up at least one SNMP probing factory on any 3-DNS Controller, BIG-IP system, EDGE-FX Cache, or GLOBAL-SITE Controller that runs the big3d agent and is in the same data center as the host.

The SNMP prober collects some or all of the following information from hosts.

  • Memory utilization
  • CPU utilization
  • Disk space utilization
  • Packet rate (packets per second
  • Throughput rate (kilobytes per second)
  • Current connections

The 3-DNS Controller uses this performance information for dynamic load balancing modes, such as Packet Rate, Quality of Service, and Kilobytes/Second.

Table 5.1 shows the host SNMP agents supported by the 3-DNS Controller.

 

SNMP Agent

Description

Generic

A generic SNMP agent is an SNMP agent that collects metrics provided by object identifiers (OIDs) as specified in the RFC 1213 document.

UCD

This free SNMP agent is provided by the University of California at Davis. It is available on the web at http://net-snmp.sourceforge.net

Solstice

This SNMP agent is a product of Sun® Microsystems.

NTServ

This SNMP matrix agent is distributed with Microsoft® Windows NT® Server 4.0.

Win2KServ

This SNMP matrix agent is distributed with Microsoft Windows 2000 Server.

Cisco LDV2

This SNMP agent is distributed with the Cisco® LocalDirector, version 2.X.

Cisco LDV3

This SNMP agent is distributed with the Cisco LocalDirector, version 3.X.

ArrowPoint

This SNMP agent is distributed with the Cisco/ArrowPoint CSS series.

Alteon

This SNMP agent is distributed with the Alteon® WebSystems ACEdirector.

Foundry

This SNMP agent is distributed with the Foundry® ServerIron.

CacheFlow

This SNMP agent is distributed with the CacheFlow® appliances.

 

Viewing host performance metrics

The Configuration utility displays the host metrics in the Host Statistics screen. The 3-DNS Controller bases the advanced load balancing decisions on packet rate, kilobytes per second, and current connections metrics, but the Host Statistics screen displays the other metrics as well, for information purposes.

Reviewing SNMP configuration issues

The SNMP probing feature requires that each host run an SNMP agent, and that the hosts and the big3d agents in the data centers have open network communication. Certain firewall configurations block SNMP communications, and you may need to verify that the firewalls in your network allow SNMP traffic to pass through.

In addition to properly configuring the SNMP agents on the hosts themselves, you need to specify SNMP host probing settings in two places in the 3-DNS configuration. First, when you define a 3-DNS Controller or BIG-IP system, you set the big3d agent to run at least one SNMP factory. Second, when you define the host servers, you configure specific SNMP agent settings for each host. For example, you need to specify the type of agent running on the host as well as the community string that allows access to the SNMP agent. Last, you configure the SNMP agent on the host itself. We recommend that you use the documentation originally provided with host to configure the SNMP agent.

Note


For more information about working with the big3d agent and SNMP, refer to Chapter 5, Probing and Metrics Collection , in the 3-DNS Reference Guide.

Working with sync groups

A sync group defines a group of 3-DNS Controllers that synchronize their configuration settings, metrics data, and zone files (optional). A sync group contains a principal system and one or more receiver systems. The principal system is the 3-DNS Controller from which the receiver systems obtain their metrics and server statistics information. You configure a sync group from the principal 3-DNS Controller. First list the IP address of the principal itself. Then list the receiver 3-DNS Controllers in the order that they should become principals if previously listed 3-DNS Controllers fail.

Configuring sync groups

The following procedures describe how to configure sync groups.

To define a sync group using the Configuration utility
  1. In the navigation pane, click 3-DNS Sync.
    The System - Add a New Sync Group screen opens.
  2. In the New Sync Group Name box, type the name of the new sync group and click Add.
    The Add a 3-DNS to a Sync Group screen opens.
  3. From the list of 3-DNS Controllers, first select the 3-DNS Controller that you want to be the principal system. Then check the box next to each 3-DNS Controller that you want to add to the sync group.
  4. Click Add.

Note


For details on how to configure a sync group from the command line, refer to Appendix A, 3-DNS Configuration File, in the 3-DNS Reference Guide.

Setting the time tolerance value

The time tolerance value is a global variable that defines the number of seconds that one 3-DNS Controller's time setting is allowed to be out of sync with another 3-DNS Controller's time setting. We recommend that you leave the time tolerance variable at the default setting of 10.

To check the value for the time tolerance setting using the Configuration utility
  1. In the navigation pane, click System.
    The System - General screen opens.
  2. On the toolbar, click Timers and Task Intervals.
  3. Note the value in the 3-DNS Sync Time Tolerance box, and change it if necessary.
  4. If you change this setting, click Update to save it. For more information about the settings on this screen, click Help on the toolbar.
To check the value for the time tolerance setting in the configuration file
  1. To ensure that the configuration files contain the same information as the memory cache, type the following command:

    3ndc dumpdb

  2. Open the wideip.conf file in a text editor (either vi or pico).
  3. Search for time_tolerance. If the time_tolerance sub-statement is not in the configuration file, the default (10) is used.
  4. Save and close the file.
  5. Commit the changes to the configuration by typing:

    3ndc reload

Overview of auto-configuration

The 3-DNS Controller automatically retrieves configuration details from BIG-IP systems, hosts, and other 3-DNS Controllers that you add to the 3-DNS configuration. This process is known as auto-configuration. Auto-configuration queries BIG-IP systems for their configuration information, including self IP addresses and virtual servers. Auto-configuration can also gather configuration information for host systems that have SNMP enabled. Using auto-configuration eliminates the repetitive tasks of entering configuration information both on the BIG-IP systems and hosts, and on the 3-DNS Controller, thus dramatically reducing administrative overhead.

Auto-configuration continually monitors the configurations for changes. When you add or remove an object from a BIG-IP system, 3-DNS Controller, or host, the change displays almost immediately in the 3-DNS configuration. The 3-DNS Controller also synchronizes the changes among the sync group members.

Once the 3-DNS Controller has retrieved the initial configuration, you modify the auto-configuration settings for each server type using the Configuration utility. Auto-configuration has three settings:

  • ON
    When the Discovery setting is set to ON, the 3-DNS Controller polls the BIG-IP systems and host systems in the network every 30 seconds to update the configuration information for those systems. Any changes, additions, or deletions are then made to the controller's configuration.
  • ON/NO DELETE
    When the Discovery setting is set to ON/NO DELETE, the 3-DNS Controller polls the BIG-IP system and host systems in the network every 30 seconds to update the configuration information for those systems. Any changes or additions are then made to the controller's configuration. Any deletions in the configuration are ignored. This setting is helpful if you want to take systems in and out of service without modifying the 3-DNS configuration.
  • OFF
    When the Discovery setting is set to OFF, the 3-DNS Controller does not collect any configuration information from the BIG-IP system and host systems in the network. Instead, you must make all changes to the configuration either by using the Configuration utility, or by editing the wideip.conf file. Note that this is the default setting.

Note


In the Configuration utility, auto-configuration is labeled Discovery.
To modify the auto-configuration setting for a BIG-IP system using the Configuration utility
  1. In the navigation pane, expand the Servers item, and then click BIG-IP.
    The BIG-IP List screen opens.
  2. Click the name of the BIG-IP system for which you want to modify the auto-configuration setting.
    The Modify BIG-IP screen opens.
  3. In the Discovery box, select one of the following settings: ON, ON/NO DELETE, or OFF.
  4. Click Update.
    The configuration updates with the new setting.
To modify the auto-configuration setting for a host using the Configuration utility
  1. In the navigation pane, expand the Servers item, and then click Host.
    The Host List screen opens.
  2. Click the name of the host for which you want to modify the auto-configuration setting.
    The Modify Host screen opens.
  3. In the Discovery box, select one of the following settings: ON, ON/NO DELETE, or OFF.
  4. Click Update.
    The configuration updates with the new setting.
To modify the auto-configuration setting for a 3-DNS Controller using the Configuration utility
  1. In the navigation pane, expand the Servers item, and then click 3-DNS.
    The 3-DNS List screen opens.
  2. Click the name of the host for which you want to modify the auto-configuration setting.
    The Modify 3-DNS screen opens.
  3. In the Discovery box, select one of the following settings: ON, ON/NO DELETE, or OFF.
  4. Click Update.
    The configuration updates with the new setting.

Configuring global variables

The global variables determine the default settings for iQuery messages, synchronization, encryption, and default load balancing parameters. The default values for the global variables are sufficient for most load balancing situations.

To configure global parameters using the Configuration utility
  1. In the navigation pane, click System.
    The System - General screen opens. Note that global parameters are grouped into several categories on this screen. Each category has its own toolbar item, and online help is available for each parameter.
  2. Make general global changes at the System - General screen or, to make changes to global parameters in other categories, click the appropriate toolbar item.
  3. Add the new global settings. For help on configuring the global settings, click Help on the toolbar.

    The new global parameters are added to your configuration.



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