Applies To:

Show Versions Show Versions

Manual Chapter: Configuration Guide for the BIG-IP® Link Controller: 2 - Essential Configuration Tasks
Manual Chapter
Table of Contents   |   << Previous Chapter   |   Next Chapter >>


2

Essential Configuration Tasks


Introducing essential configuration tasks

When you integrate a Link Controller into your network, you must complete a specific set of tasks for the capabilities of the Link Controller to be available to you. These steps are:

  • Create a default gateway pool, which contains the links available for load balancing traffic
  • Add links that the Link Controller will manage
  • Add a listener that identifies the traffic for which the Link Controller must load balance
  • Add a pool that will contain the virtual servers to which the Link Controller will load balance inbound traffic.
  • Add virtual servers that represent the resources to which the Link Controller will load balance inbound traffic.
  • Add a wide IP for which the Link Controller will load balance inbound traffic
  • Configure address translation settings for inbound and outbound traffic management

Once you complete these essential configuration tasks, you can customize how the link controller manages inbound and outbound traffic. For example, you can determine if you want to load balance traffic based on cost, bandwidth, or application. You can also define specific geographic regions, called topologies, that allow you to load balance traffic based on the traffic destination.

Note

The Link Controller uses an auto-discovery feature to manage and maintain links. You can access this feature from the Main tab of the navigation pane by expanding System, clicking General Properties, and then choosing General from the Global Traffic menu. Do not disable this feature; doing so causes the Link Controller to mark all links as down and be unable to manage traffic.
Note

If your environment requires that the Link Controller operate in a fail-safe or high availability mode, see the section titled Configuring fail-safe in Chapter 13, Setting Up a Redundant System, in the BIG-IP Network and System Management Guide.

Creating the default gateway pool

One of the most important tasks you want to complete when adding links to the Link Controller configuration is the creation of a default gateway pool. A default gateway pool is a collection of the routers available for handling the network's inbound and outbound traffic. The Link Controller requires the default gateway pool to load balance traffic across different routers, ensuring that network traffic flows in an efficient and cost-effective manner.

To create a default gateway pool

  1. On the Main tab of the navigation pane, expand Local Traffic and then click Pools.
    The main pools screen appears.
  2. Click the Create button.
    The create pool screen appears.
  3. In the Name box, type the name of the pool.
    We recommend you use a name such as default_gateway_pool.
  4. In the New Members section, add the IP addresses associated with each router, to add the routers to the pool.
  5. Configure additional options for the pool as needed.
    Advanced options for pools are displayed when you select Advanced from the Configuration list.
  6. Click Finished to save your changes.

Implementing the default gateway pool

After you create a default gateway pool, you must instruct the Link Controller to use the pool as the default gateway connection between the internal network and the Internet.

To implement the default gateway pool

  1. On the Main tab of the navigation pane, expand Network and then click Routes.
    The main routes screen opens.
  2. Click the Add button.
    The add route page opens.
  3. From the Type list, select Default Gateway.
  4. From the Resource section, select Use Pool.
    A list appears, allowing you to select the pool of links.
  5. Select the pool name that represents the group of links you want to use as the default gateway pool.
  6. Click Finished to save your changes.

Adding links

Before you can load balance inbound and outbound traffic on the Link Controller, you must add at least one link and configure its basic properties. These properties include settings such as the router address of the link, as well as the limit thresholds for inbound and outbound traffic.

To add a link

  1. On the Main tab of the navigation pane, expand Link Controller, and then click Links.
    The main link screen opens.
  2. Click the Create button.
    The New Link screen opens.
  3. In the Name box, type a name for the link.
  4. In the Router Address box, type the IP address to associate with the link.
  5. In the Uplink Address box, type the IP address to associate with the Internet Service Provider to which outgoing traffic is sent.
  6. In the Service Provider box, type the name of the Internet Service Provider.
  7. Select the health monitors that the Link Controller uses to determine the availability of the link.
    To select a health monitor, click the name of the monitor from the Available list within the Health Monitors area, then use the [<<] button to add the monitor to the Active list. It is recommended that you add at least the bigip_link and snmp_link monitors.
  8. Click the Finish button to save your changes.

For additional information on adding and managing links, see Chapter 3, Defining Links .

Adding listeners

One of the most crucial aspects of integrating the Link Controller into your network is providing it with the means of identifying the network traffic for which it is responsible. A listener is a resource for the Link Controller that listens on an IP address on which the system intercepts traffic. Listening is a process in which a component, such as a listener, passively checks incoming traffic and initiates an action only if a packet matches a set of criteria. Each listener that you define listens only for DNS packets on port 53. The Link Controller then handles only network traffic sent to that IP address.

Note

The IP address that you supply for a listener typically is the IP address you assigned to the Link Controller.

In most situations, a Link Controller is responsible for traffic that traverses multiple VLANs. Consequently, you can configure a listener to monitor as many or as few VLANs as necessary.

To configure a listener

  1. On the Main tab of the navigation pane, expand Link Controller, and then click Listeners.
    The listener main screen opens.
  2. Click the Create button.
    The New Listener screen opens.
  3. In the Destination box, type the IP address on which the Link Controller will listen for network traffic.
    The Link Controller will handle only network traffic sent to this IP address. In typical configurations, the IP address for a listener is the IP address assigned to the Link Controller.
  4. From the VLAN Traffic list, select a VLAN setting appropriate for this listener.
    For additional assistance with this setting, see the online help for this screen.
  5. Click the Create button to save the new listener.

Repeat this process for any additional listeners.

For additional information on adding and managing listeners, see Chapter 4, Working with Listeners .

Adding pools

A load balancing pool is a set of devices, such as web servers, that you group together to receive and process traffic. Instead of sending client traffic to the destination IP address specified in the client request, the Link Controller sends the request to any of the servers that are members of that pool.

To create a load balancing pool

  1. On the Main tab of the navigation pane, expand Local Traffic and then click Pools.
    The main pools screen opens.
  2. Click the Create button.
    The New Pool screen opens.
  3. From the Configuration list, select Advanced.
    This displays additional fields, and allows you to modify additional default settings.
  4. For the Name setting, type a name for the pool.
  5. Specify, retain, or change each of the other settings.
    For information on pool settings, see Configuring pool settings, in Chapter 5 , or refer to the online help for this screen.
  6. Click the Finished button to save your changes.

For more information on adding and managing pools, see Chapter 5, Configuring Load Balancing Pools .

Adding virtual servers

A key requirement for the Link Controller is adding the virtual servers to which the Link Controller load balances inbound and outbound traffic. A virtual server is a specific network resource and, at a minimum, is identified by an IP address and port number.

To add a virtual server

  1. On the Main tab of the navigation pane, expand Local Traffic and then click Virtual Servers.
    The main screen for virtual servers appears.
  2. Click the Create button.
    The New Virtual Server screen opens.
  3. In the Name box, type the name of the virtual server.
  4. Define the destination of the virtual server.
    1. Select the appropriate destination type: if the virtual server represents a single resource select Host, if the virtual server represents a group of resources, select Network from the Destination section.
    2. In the Address box, type the IP address of the virtual server.
  5. In the Service Port option, type the port number that the virtual server uses.
    Alternatively, you can select a port from the adjacent list. For example, if you select HTTP from the list, the corresponding box automatically updates to contain the corresponding port number, 80.
  6. Configure the remaining properties associated with this virtual server as needed.
  7. Click the Finished button to save the new virtual server configuration.

For additional information on adding and managing virtual servers, see Chapter 6, Configuring Virtual Servers .

Adding wide IPs

A wide IP is a mapping of a fully-qualified domain name (FQDN) to a set of virtual servers that host the domain's content, such as a web site, an e-commerce site, or a content delivery network (CDN). You establish wide IPs within a Link Controller to determine how the Link Controller manages inbound traffic.

To add a wide IP

  1. On the Main tab of the navigation pane, expand Link Controller, and then click Inbound Wide IPs.
    The main wide IP screen opens.
  2. Click the Create button.
    The New Wide IP screen opens.
  3. In the Name box, type a name that identifies the wide IP.
  4. In the TTL box, type the time-to-live value you want to associate with this wide IP.
  5. From the Load Balancing section, select the appropriate load balancing modes.
    You can select a load balancing mode at three different levels: Preferred, Alternate, and Fallback. These modes are described in detail in Chapter 9, Inbound Load Balancing .
  6. For the Member List setting, add the virtual servers that belong to this wide IP.
  7. Click the Finished button to save the new wide IP.

Repeat this process for any other wide IPs that you want to create.

For additional information on adding and managing wide IPs, see Chapter 7, Defining Wide IPs .

Configuring address translation

A virtual server configured on a Link Controller system translates the destination IP address of an incoming packet to another destination IP address, for the purpose of load balancing that packet. Normally, the source IP address remains unchanged.

As an option, you can also create a secure network address translation (SNAT). A SNAT is an object that maps an original client IP address (that is, a source IP address) to a translation address that you choose. Thus, a SNAT causes the Link Controller to translate the source IP address of an incoming packet to an address that you specify. The purpose of a SNAT is simple: to ensure that the target server sends its response back through the Link Controller rather than to the original client IP address directly.

As an alternative to SNAT, the Link Controller also supports network address translation (NAT). A NAT provides an alias IP address that a node can use as its source IP address when making or receiving connections to clients on the external network. (This distinguishes it from a SNAT, which can initiate but not receive a connection.)

The Link Controller supports multiple types of SNAT and NAT implementations. The following steps outline the most basic SNAT implementation, referred to as a standard implementation, which maps a source IP address directly to another IP address.

To configure secure address translation

  1. On the Main tab of the navigation pane, expand Local Traffic, and then click SNATs.
    The main SNAT screen opens.
  2. Click the Create button.
    The New SNAT screen opens.
  3. In the Name box, type a unique name for the SNAT.
  4. In the Translation box, select IP Address.
  5. Type an IP address in the adjacent box.
  6. Click the Finished button to save your changes.

For additional information on SNAT and NAT configurations, see Chapter 19, Configuring SNATs and NATs .




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)