Configuring SDM Templates

The Catalyst 2960 switch command reference has command syntax and usage information.

•Understanding the SDM Templates

•Configuring the Switch SDM Template

•.Displaying the SDM Templates

Understanding the SDM Templates

You can use SDM templates to configure system resources in the switch to optimize support for specific features, depending on how the switch is used in the network. You can select a template to provide maximum system usage for some functions or use the default template to balance resources.

To allocate ternary content addressable memory (TCAM) resources for different usages, the switch SDM templates prioritize system resources to optimize support for certain features. You can select SDM templates to optimize these features:

•Default—The default template gives balance to all functions.

•Dual—The dual IPv4 and IPv6 template allows the switch to be used in dual stack environments (supporting both IPv4 and IPv6). Using the dual stack templates results in less TCAM capacity allowed for each resource. Do not use them if you plan to forward only IPv4 traffic.

•QoS—The QoS template maximizes system resources for quality of service (QoS) access control entries (ACEs).

Table 6-1 Approximate Number of Feature Resources Allowed by Each Template 

Resource
Default
QoS
Dual

Unicast MAC addresses

8 K

8 K

8 K

IPv4 IGMP groups

256

256

256

IPv4 unicast routes

0

0

0

IPv6 multicast groups

0

0

0

Directly connected IPv6 addresses

0

0

0

Indirect IPv6 unicast routes

0

0

0

IPv4 policy-based routing aces

0

0

0

IPv4 MAC QoS ACEs

128

384

0

IPv4 MAC security ACEs

384

128

256

IPv6 policy-based routing aces

0

0

0

IPv4 MAC QoS ACEs

0

0

0

IPv4 MAC security ACEs

0

0

0


The rows in the tables represent approximate hardware boundaries set when a template is selected. If a section of a hardware resource is full, all processing overflow is sent to the CPU, seriously impacting switch performance.

Configuring the Switch SDM Template

These sections contain this configuration information:

•Default SDM Template

•SDM Template Configuration Guidelines

•Setting the SDM Template

Default SDM Template

The default template is the default.

SDM Template Configuration Guidelines

Follow these guidelines when selecting and configuring SDM templates:

•When you select and configure SDM templates, you must reload the switch for the configuration to take effect.

•If you try to configure IPv6 features without first selecting a dual IPv4 and IPv6 template, a warning message is generated.

•Using the dual stack templates results in less TCAM capacity allowed for each resource, so do not use if you plan to forward only IPv4 traffic.

Setting the SDM Template

Beginning in privileged EXEC mode, follow these steps to use the SDM template to maximize feature usage:

 
Command
Purpose

Step 1 

configure terminal

Enter global configuration mode.

Step 2 

sdm prefer {default | dual-ipv4-and-ipv6 default | qos}

Specify the SDM template to be used on the switch:

The keywords have these meanings:

•default—Gives balance to all functions.

•dual-ipv4-and-ipv6 default—Allows the switch to be used in dual stack environments (supporting both IPv4 and IPv6).

•qos—Maximizes system resources for QoS ACEs.

Use the no sdm prefer command to set the switch to the default template. The default template balances the use of system resources.

Step 3 

end

Return to privileged EXEC mode.

Step 4 

reload

Reload the operating system.

After the system reboots, you can use the show sdm prefer privileged EXEC command to verify the new template configuration. If you enter the show sdm prefer command before you enter the reload privileged EXEC command, the show sdm prefer command shows the template currently in use and the template that will become active after a reload.

.Displaying the SDM Templates

Use the show sdm prefer privileged EXEC command with no parameters to display the active template.

Use the show sdm prefer [default | dual-ipv4-and-ipv6 default | qos] privileged EXEC command to display the resource numbers supported by the specified template.