Cisco Cisco IOS Software Release 12.2(18)SXE

The IOS SLB feature is an IOS-based solution that provides load balancing for a variety of networked 
devices and services, including:

Application servers, such as Hypertext Transfer Protocol (HTTP), Telnet, File Transfer Protocol 
(FTP), and so on

Firewalls

Service nodes, such as authentication, authorization, and accounting (AAA) servers, web caches, 
and so on

In addition, the IOS SLB Exchange Director enables advanced load-balancing routing capabilities for 
the following additional service nodes:

Cisco Mobile Exchange (CMX) components:

Cisco Content Services Gateways (CSGs)

Cisco gateway GPRS support nodes (GGSNs)

Cisco Service Selection Gateways (SSGs)

Cisco Home Agents

Other components for mobile, Public Wireless LAN (PWLAN), and Service Provider networks:

Wireless Application Protocol (WAP) gateways

Protocol optimization gateways

Non-Cisco GGSNs and Home Agents

Other RADIUS-aware flow gateways. These gateways are proxies or routing nodes that receive 
RADIUS Authorization and Accounting requests for users that route flows through the 
gateways. The Exchange Director binds the RADIUS and data flows to the same gateway, 
ensuring that the gateway receives a complete and consistent view of the network activity for 
the user.

The Exchange Director also adds the following features:

Enhanced failover capabilities for single-chassis failover within the CMX for Catalyst 6500 family 
switches and Cisco 7600 series routers. When used with Route Processor Redundancy Plus (RPR+), 
IOS SLB stateful backup for redundant route processors provides full IOS SLB stateful failover for 
these platforms.

Flow persistence, which provides intelligent return routing of load-balanced IP flows.

 illustrates a logical view of a simple IOS SLB network.