Configuring Cost-based Load Balancing

Overview: Configuring cost-based load balancing

Important: This functionality is not currently available in the U.S.

You can configure BIG-IP® Link Controller™ to use cost-based load balancing to manage the traffic flowing in and out of a network. In cost-based load balancing, you prioritize link usage based on the cost of the bandwidth for the connection to the Internet. Link Controller sends traffic to the link that is currently operating at the lowest cost. As the usage cost for each link changes, Link Controller dynamically shifts traffic to the best link.

The following illustration shows a network for configuring a cost-based load balancing configuration.

As the illustration shows, while traffic remains below a certain level (for example, 4 Mbps), the Link Controller uses the Primary Link. If traffic exceeds a certain level (for example, 4 Mbps), the Link Controller sends the overflow traffic to the Secondary Link. If a link goes offline for any reason, Link Controller uses the Alternate and Fallback load balancing methods to route traffic through an available link.

Task summary for cost-based load balancing

Important: This functionality is not currently available in the U.S.

Use the tasks in this implementation to create a cost-based, load balancing configuration to manage the traffic flowing in and out of a network.

Task list

Creating the first cost-based link for load balancing

Gather the IP address of the router associated with the ISP and IP address that corresponds with the external Internet connection. In addition, determine an amount of appropriate bandwidth for the link.

Create and configure the first link on Link Controller™to specify how traffic enters and leaves your network.

1. On the Main tab, click Link Controller > Links.

   The Links List screen opens.

2. Click Create.

   The New Link screen opens.

3. In the Name field, type a name for the link.

   Important: Link names are limited to 63 characters.

4. In the Router Address field, type the IP address of the router.

5. In the Uplink Address field, type the IP address that corresponds with the external Internet connection.

6. For the Service Provider field, type the name of the ISP provider.

7. From the Configuration list, select Advanced.

   Additional controls display on the screen.

8. From the Weighting list, select Price (Dynamic Ratio).

9. From the Prepaid Segment field, type the amount of bandwidth that is prepaid for the link.

10. From the Incremental Segments field, add the incremental segment price.

11. Click Create.

    The Link List screen displays.

Creating the second cost-based link for load balancing

Gather the IP address of the router associated with the ISP and IP address that corresponds with the external Internet connection. In addition, determine an amount of appropriate bandwidth for the link.

Create and configure the second link on Link Controller™to specify how traffic enters and leaves your network.

1. On the Main tab, click Link Controller > Links.

   The Links List screen opens.

2. Click Create.

   The New Link screen opens.

3. In the Name field, type a name for the link.

   Important: Link names are limited to 63 characters.

4. In the Router Address field, type the IP address of the router.

5. In the Uplink Address field, type the IP address that corresponds with the external Internet connection.

6. For the Service Provider field, type the name of the ISP provider.

7. From the Configuration list, select Advanced.

   Additional controls display on the screen.

8. From the Weighting list, select Price (Dynamic Ratio).

9. From the Prepaid Segment field, type the amount of bandwidth that is prepaid for the link.

10. Click Create.

    The Link List screen displays.

11. From the Incremental Segments field, add the incremental segment price.

Creating a default gateway pool

Gather the IP addresses associated with each link.

Create a default gateway pool to load balance the outbound traffic across the links.

1. On the Main tab, click Local Traffic > Pools.

   The Pools list screen opens.

2. Click Create.

   The New Pool screen opens.

3. In the Name field, type a name for the pool.

   Names must begin with a letter, and can contain only letters, numbers, and the underscore (_) character.

   Important: The pool name is limited to 63 characters.

4. In the New Members area, add the IP addresses associated with each link.

   1. In the Address field, type the IP address.

   2. Click Add.

5. Click Finished.

Creating a default route to the internet

Configure Link Controller to use the pool as the default gateway connection between the internal network and the internet.

1. On the Main tab, click Network > Routes.

2. Click Add.

   The New Route screen opens.

3. In the Name field, type a unique name.

4. From the Resource list, select Use Pool.

5. From the Pool list, select default_gateway_pool.

6. Click Finished.

Creating virtual servers to load balance connections across servers

Gather the IP addresses you want to use for creating the virtual servers.

Create two virtual servers, one for each link, to load balance inbound connections across the servers on the network.

1. On the Main tab, click Local Traffic > Virtual Servers.

   The Virtual Server List screen opens.

2. Click Create.

   The New Virtual Server screen opens.

3. In the Name field, type a unique name for the virtual server.

4. In the Destination Address/Mask field, type the IP address you want to use for the virtual server.

5. In the Service Port field, type 80, or select HTTP from the list.

6. Click Finished.

7. Repeat these steps to create the second virtual server.

Creating a wildcard virtual server

Create a wildcard server to load balance outbound connections across the routers.

1. On the Main tab, click Local Traffic > Virtual Servers.

   The Virtual Server List screen opens.

2. Click Create.

   The New Virtual Server screen opens.

3. In the Name field, type a unique name for the virtual server.

4. For the Destination setting, select Host, and type 0.0.0.0 in the Address field.

5. In the Service Port field, type 0.

   Note: Port 0 defines a wildcard virtual server that handles all types of services. If you specify a port number, you create a port-specific wildcard virtual server. In that case, the wildcard virtual server handles traffic only for the specified port.

6. Click Finished.

Creating a wide IP

Before you can create a wide IP, you need IP addresses from two previously created virtual servers.

Create a wide IP to which Link Controller™ load balances incoming DNS requests.

1. On the Main tab, click Link Controller > Inbound Wide IPs.

   The Wide IP List screen opens.

2. Click Create.

   The New Wide IP screen opens.

3. In the Name field, type a name for the wide IP.

4. From the Type list, select a record type for the wide IP.

5. From the Load Balancing Method list, make selections from the Preferred, Alternate, and Fallback lists.

6. For the Member List field, add the address of the appropriate virtual server.

   1. From the Virtual Server list, select a virtual server.

   2. Click Add.

7. Click Create.

Implementation result for cost-based load balancing

You now have Link Controller™ configured to use cost-based load balancing to manage DNS traffic.