Cisco Systems 78-11741-02 manual Specifying a Server Farm, Specifying a Load-Balancing Algorithm

Configuring Server Load Balancing

IOS SLB Configuration Task List

•Enabling the Real Server for Service (Required)

•Specifying a Virtual Server (Required)

•Associating a Virtual Server with a Server Farm (Required)

•Configuring Virtual Server Attributes (Required)

•Adjusting Virtual Server Values (Optional)

•Preventing Advertisement of Virtual Server Address (Optional)

•Enabling the Virtual Server for Service (Required)

•Configuring IOS SLB Dynamic Feedback Protocol (Optional)

•Configuring NAT (Optional)

•Implementing IOS SLB Stateless Backup (Optional)

•Verifying IOS SLB (Optional)

•Troubleshooting IOS SLB (Optional)

Specifying a Server Farm

Grouping real servers into server farms is an essential part of IOS SLB. Using server farms enables IOS SLB to assign new connections to the real servers based on their weighted capacities, and on the load-balancing algorithms used.

To configure a server farm, use the following command in global configuration mode:

Command	Purpose
Router(config)# ip slb serverfarm serverfarm-name	Adds a server farm definition to the IOS SLB
	configuration and initiates SLB server farm
	configuration mode.

Specifying a Load-Balancing Algorithm

To determine which real server to use for each new connection request, the IOS SLB feature uses one of two load-balancing algorithms: weighted round robin (the default) or weighted least connections. (See the “Weighted Round Robin” section or the “Weighted Least Connections” section for detailed descriptions of these algorithms.) To specify the load-balancing algorithm, use the following command in SLB server farm configuration mode:

Command	Purpose
Router(config-slb-sfarm)#predictor [roundrobin leastconns]	Specifies whether the weighted round robin
	algorithm or the weighted least connections
	algorithm is to be used to determine how a real
	server is selected.

Cisco IOS IP Configuration Guide

IPC-141