Manual Chapter : Working with Route Domains

Applies To:

Show Versions Show Versions

BIG-IP Edge Gateway

  • 11.2.1


  • 11.2.1


  • 11.2.1

BIG-IP Link Controller

  • 11.2.1


  • 11.2.1

BIG-IP WebAccelerator

  • 11.2.1


  • 11.2.1


  • 11.2.1


  • 11.2.1
Manual Chapter

What is a route domain?

A route domain is a configuration object that isolates network traffic for a particular application on the network.

Because route domains segment network traffic, you can assign the same IP address or subnet to multiple nodes on a network, provided that each instance of the IP address resides in a separate routing domain.

Note: Route domains are compatible with both IPv4 and IPv6 address formats.
Important: For systems that include both BIG-IP Local Traffic Manager (LTM) and BIG-IP Global Traffic Manager (GTM), you can configure route domains on internal interfaces only.

Benefits of route domains

Using the route domains feature of the BIG-IP system, you can provide hosting service for multiple customers by isolating each type of application traffic within a defined address space on the network.

With route domains, you can also use duplicate IP addresses on the network, provided that each of the duplicate addresses resides in a separate route domain and is isolated on the network through a separate VLAN. For example, if you are processing traffic for two different customers, you can create two separate route domains. The same node address (such as can reside in each route domain, in the same pool or in different pools, and you can assign a different monitor to each of the two corresponding pool members.

Sample partitions with route domain objects

This illustration shows two route domain objects on a BIG-IP system, where each route domain corresponds to a separate customer, and thus resides in its own partition. Within each partition, the customer created the network objects and local traffic objects required for that customer's application (AppA or AppB).
Sample partitions with route domains

Sample route domain deployment

A good example of the use of route domains is a configuration for an ISP that services multiple customers, where each customer deploys a different application. In this case, the BIG-IP system isolates traffic for two different applications into two separate route domains. The routes for each application's traffic cannot cross route domain boundaries because cross-routing restrictions are enabled on the BIG-IP system by default.
A sample route domain deployment

About route domain IDs

A route domain ID is a unique numerical identifier for a route-domain. You can assign objects with IP addresses (such as self IP addresses, virtual addresses, pool members, and gateway addresses) to a route domain by appending the %ID to the IP address.

The format required for specifying a route domain ID in an object’s IP address is A.B.C.D%ID, where ID is the ID of the relevant route domain. For example, both the local traffic node object and the pool member pertain to route domain 2.

The BIG-IP system includes a default route domain with an ID of 0. If you do not explicitly create any route domains, all routes on the system pertain to route domain 0.

Important: A route domain ID must be unique on the BIG-IP system; that is, no two route domains on the system can have the same ID.

Traffic forwarding between route domains

Forwarding of traffic between route domains is by default enabled between route domains in a parent-child relationship only. (That is, traffic received in a child route domain can be forwarded to a parent route domain and the reverse.) Consequently, by default, the BIG-IP system does not load balance traffic arriving in route domain 1 to servers in any other route domain, except for the parent route domain.

You can control this behavior by configuring the Strict Isolation feature of a route domain. For example, to allow traffic forwarding between route domains 1 and 2, (without making route domain 2 a parent of route domain 1 or route domain 1 a parent of route domain 2), you must disable the Strict Isolation property on both route domains.

About parent IDs

Each route domain can have a parent route domain, identified with a parent ID. The parent ID identifies another route domain on the system that the system can search to find a route.

For example, suppose you create route domain 1 with a parent ID of 0. For traffic pertaining to route domain 1, the system looks within route domain 1 for a route for the specified destination. If no route is found, the system searches the routes in route domain 0.

If the system finds no route in the parent route domain, the system searches the parent route domain’s parent, and so on, until the system finds either a match or a route domain with no parent. In the latter case, the system refrains from searching any other route domains to find a match, thus preventing the system from using a route from another route domain.

About VLANs and tunnels for a route domain

You can assign one or more VLANs, VLAN groups, or tunnels to a route domain. The VLANs, VLAN groups, or tunnels that you assign to a route domain are those pertaining to the particular traffic that you want to isolate in that route domain. Each VLAN, VLAN group, or tunnel can be a member of one route domain only.

When you assign a VLAN group to a route domain, the BIG-IP system automatically assigns the VLAN group members to the route domain.

Please note the following facts:

  • If you delete a VLAN group from the system, the VLAN group members remain assigned to the route domain.
  • If a VLAN is assigned to a non-default route domain and you delete that route domain, the BIG-IP system automatically assigns the VLAN to the default route domain for that partition.
  • When you create VLANs, VLAN groups, and tunnels, the BIG-IP system automatically assigns them to the default route domain of the current partition. You can change this assignment when you create other route domains in the partition.

About dynamic routing protocols for a route domain

For each route domain that you configure, you can enable one or more dynamic routing protocols. Use of dynamic routing for route domain 0 or any other route domain is optional.

About default route domains for administrative partitions

The route domains feature includes the concept of default route domains, to minimize the need for you to specify the %ID notation. When you designate a route domain as the default route domain in a partition, any BIG-IP system objects in that partition that do not include the %ID notation in their IP addresses are automatically associated with the default route domain.

The default route domain for partition Common

The BIG-IP system, by default, includes one route domain, named route domain 0. Route domain 0 is known as the default route domain on the BIG-IP system, and this route domain resides in administrative partition Common. If you do not create any other route domains on the system, all traffic automatically pertains to route domain 0.

If you want to segment traffic into multiple route domains, you can create additional route domains in partition Common and then segment application traffic among those route domains. Any BIG-IP addresses that do not include the route domain ID notation are automatically associated with the default route domain.

Note: Any VLANs that reside in partition Common are automatically assigned to the default route domain.

The default route domain for other partitions

For administrative partitions other than Common, you can create a route domain and designate it as a partition default route domain. A partition can contain one partition default route domain only.

The benefit of having a partition default route domain is that when you create objects such as a virtual server and pool members within that partition, you do not need to specify the ID of that default route domain within the addresses for those objects. For example, if you create a partition default route domain with an ID of 2 in partition A, the system automatically assigns any partition A object IP addresses without a route domain ID to route domain 2.

If no partition default route domain exists within the partition, the system associates those addresses with route domain 0 in partition Common.

Creating a route domain on a BIG-IP LTM system

Before you create a route domain, ensure that an external and internal VLAN exist on a BIG-IP® LTM® system.
You can create a route domain on BIG-IP LTM to segment (isolate) network traffic on your network.
  1. On the Main tab, click Network > Route Domains. The Route Domain List screen opens.
  2. Click Create. The New Route Domain screen opens.
  3. In the Name field, type a name for the route domain. This name must be unique within the administrative partition in which the route domain resides.
  4. In the ID field, type an ID number for the route domain. This ID must be unique on the BIG-IP system; that is, no other route domain on the system can have this ID.
  5. In the Description field, type a description of the route domain. For example: This route domain applies to traffic for application MyApp.
  6. For the Strict Isolation setting, select the Enabled check box to restrict traffic in this route domain from crossing into another route domain.
  7. For the Parent Name setting, retain the default value.
  8. For the VLANs setting, from the Available list, select a VLAN name and move it to the Members list. Select the VLAN that processes the application traffic relevant to this route domain. Configuring this setting ensures that the BIG-IP system immediately associates any self IP addresses pertaining to the selected VLANs with this route domain.
  9. For the Dynamic Routing Protocols setting, from the Available list, select one or more protocol names and move them to the Enabled list. You can enable any number of listed protocols for this route domain. This setting is optional.
  10. From the Partition Default Route Domain list, select either Another route domain (0) is the Partition Default Route Domain or Make this route domain the Partition Default Route Domain. This setting does not appear if the current administrative partition is partition Common. When you configure this setting, either route domain 0 or this route domain becomes the default route domain for the current administrative partition.
  11. Click Finished. The system displays a list of route domains on the BIG-IP system.
You now have another route domain on the BIG-IP system.