Catalyst 3750-E and 3560-E Switch Software Configuration Guide, 12.2(35)SE2
Configuring SDM Templates
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Configuring SDM Templates

Table Of Contents

Configuring SDM Templates

Understanding the SDM Templates

Dual IPv4 and IPv6 SDM Templates

SDM Templates and Switch Stacks

Configuring the Switch SDM Template

Default SDM Template

SDM Template Configuration Guidelines

Setting the SDM Template

Displaying the SDM Templates


Configuring SDM Templates


This chapter describes how to configure the Switch Database Management (SDM) templates on the Catalyst 3750-E or 3560-E switch. Unless otherwise noted, the term switch refers to a Catalyst 3750-E or 3560-E standalone switch and to a Catalyst 3750-E switch stack.


Note For complete syntax and usage information for the commands used in this chapter, see the command reference for this release.


This chapter consists of these sections:

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; for example, use the default template to balance resources, and use access template to obtain maximum ACL usage.

To allocate hardware resources for different usages, the switch SDM templates prioritize system resources to optimize support for certain features. You can select SDM templates for IP Version 4 (IPv4) to optimize these features:

Routing—The routing template maximizes system resources for unicast routing, typically required for a router in the center of a network.

VLANs—The VLAN template disables routing and supports the maximum number of unicast MAC addresses. It would typically be selected for a Layer 2 switch.

Default—The default template gives balance to all functions.

Access—The access template maximizes system resources for access control lists (ACLs) to accommodate a large number of ACLs.

The switch supports only the desktop templates.

Table 8-1 lists the approximate numbers of each resource supported in each of the four templates for a desktop switch.

Table 8-1 Approximate Number of Feature Resources Allowed by Each Template 

Resource
Access
Default
Routing
VLAN

Unicast MAC addresses

4 K

6 K

3 K

12 K

IGMP groups and multicast routes

1 K

1 K

1 K

1 K

Unicast routes

6 K

8 K

11 K

0

Directly connected hosts

4 K

6 K

3 K

0

Indirect routes

2 K

2 K

8 K

0

Policy-based routing ACEs

0.5 K

0

0.5 K

0

QoS classification ACEs

0.5 K

0.5 K

0.5 K

0.5 K

Security ACEs

2 K

1 K

1 K

1 K

VLANs

1 K

1 K

1 K

1 K


The first eight rows in the tables (unicast MAC addresses through security ACEs) 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. The last row is a guideline used to calculate hardware resource consumption related to the number of Layer 2 VLANs on the switch.

Dual IPv4 and IPv6 SDM Templates

You can select SDM templates to support IP Version 6 (IPv6). For more information about IPv6 and how to configure IPv6 unicast routing, see "Configuring IPv6 Unicast Routing."

This software release does not support IPv6 multicast routing and QoS.

This software release does not support Policy-Based Routing (PBR) when forwarding IPv6 traffic. The software supports IPv4 PBR only when the dual-ipv4-and-ipv6 routing template is configured.

The dual IPv4 and IPv6 templates allow the switch to be used in dual stack environments (supporting both IPv4 and IPv6). Using the dual stack templates results in less hardware capacity allowed for each resource. Do not use them if you plan to forward only IPv4 traffic. These SDM templates support IPv4 and IPv6 environments:

Dual IPv4 and IPv6 default template—supports Layer 2, multicast, routing, QoS, and ACLs for IPv4; and Layer 2, routing, and ACLs for IPv6 on the switch.

Dual IPv4 and IPv6 routing template—supports Layer 2, multicast, routing (including policy-based routing), QoS, and ACLs for IPv4; and Layer 2, routing, and ACLs for IPv6 on the switch.

Dual IPv4 and IPv6 VLAN template—supports basic Layer 2, multicast, QoS, and ACLs for IPv4, and basic Layer 2 and ACLs for IPv6 on the switch.

Table 8-2 defines the approximate feature resources allocated by each new template for a desktop switch. Template estimations are based on a switch with 8 routed interfaces and 1024 VLANs.

Table 8-2 Approximate Feature Resources Allowed by Dual IPv4-IPv6 Templates 

Resource
IPv4-and-IPv6 Default
IPv4-and-IPv6 Routing
IPv4-and-IPv6 VLAN

Unicast MAC addresses

2 K

1.5 K

8 K

IPv4 IGMP groups and multicast routes

1 K

1 K

1 K for IGMP groups

0 for multicast routes

Total IPv4 unicast routes:

3 K

2.75 K

0

Directly connected IPv4 hosts

2 K

1.5 K

0

Indirect IPv4 routes

1 K

1.25 K

0

IPv6 multicast groups

1 K

1 K

1 K

Directly connected IPv6 addresses

2 K

1.5 K

0

Indirect IPv6 unicast routes

1 K

1.25 K

0

IPv4 policy-based routing ACEs

0

0.25 K

0

IPv4 or MAC QoS ACEs (total)

0.5 K

0.5 K

0.5 K

IPv4 or MAC security ACEs (total)

1 K

0.5 K

1 K

IPv6 security ACEs

0.5 K

0.5 K

0.5 K


SDM Templates and Switch Stacks

In a Catalyst 3750-E-only or a mixed hardware switch stack, all stack members must use the same SDM desktop template that is stored on the stack master. When a new switch is added to a stack, the SDM configuration that is stored on the stack master overrides the template configured on an individual switch. For more information about stacking, see Chapter 5, "Managing Switch Stacks."

You can use the show switch privileged EXEC command to see if any stack members are in SDM mismatch mode. This example shows the output from the show switch privileged EXEC command when an SDM mismatch exists:

Switch# show switch 
                                               Current 
Switch#  Role      Mac Address     Priority     State 
------------------------------------------------------------ 
*2       Master    000a.fdfd.0100     5         Ready               

4        Member     0003.fd63.9c00    5        SDM Mismatch

This is an example of a syslog message notifying the stack master that a stack member is in SDM mismatch mode:

2d23h:%STACKMGR-6-SWITCH_ADDED_SDM:Switch 2 has been ADDED to the stack (SDM_MISMATCH)

2d23h:%SDM-6-MISMATCH_ADVISE:
2d23h:%SDM-6-MISMATCH_ADVISE:
2d23h:%SDM-6-MISMATCH_ADVISE:System (#2) is incompatible with the SDM 
2d23h:%SDM-6-MISMATCH_ADVISE:template currently running on the stack and 
2d23h:%SDM-6-MISMATCH_ADVISE:will not function unless the stack is 
2d23h:%SDM-6-MISMATCH_ADVISE:downgraded.  Issuing the following commands 
2d23h:%SDM-6-MISMATCH_ADVISE:will downgrade the stack to use a smaller 
2d23h:%SDM-6-MISMATCH_ADVISE:compatible desktop SDM template:
2d23h:%SDM-6-MISMATCH_ADVISE:
2d23h:%SDM-6-MISMATCH_ADVISE:    "sdm prefer vlan desktop" 
2d23h:%SDM-6-MISMATCH_ADVISE:    "reload"

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 Switch Database Management (SDM) desktop template.

SDM Template Configuration Guidelines

Follow these guidelines when selecting and configuring SDM templates:

You must reload the switch for the configuration to take effect.

Use the sdm prefer vlan global configuration command on switches intended for Layer 2 switching with no routing.

When you use the VLAN template, no system resources are reserved for routing entries, and any routing is done through software. This overloads the CPU and severely degrades routing performance.

Do not use the routing template if you do not have routing enabled on your switch. To prevent other features from using the memory allocated to unicast routing in the routing template, use the sdm prefer routing global configuration command.

If you try to configure IPv6 without first selecting a dual IPv4 and IPv6 template, a warning message appears.

Using the dual stack template results in less hardware capacity allowed for each resource, so do not use it 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 {access | default | dual-ipv4-and-ipv6 {default | routing | vlan} | routing | vlan}

Specify the SDM template to be used on the switch:

The keywords have these meanings:

access—Maximizes system resources for ACLs.

default—Gives balance to all functions.

dual-ipv4-and-ipv6—Select a template that supports both IPv4 and IPv6 routing.

default—Balance IPv4 and IPv6 Layer 2 and Layer 3 functionality.

routing—Provide maximum usage for IPv4 and IPv6 routing, including IPv4 policy-based routing.

vlan—Provide maximum usage for IPv4 and IPv6 VLANs.

routing—Maximizes routing on the switch.

vlan—Maximizes VLAN configuration on the switch with no routing supported in hardware.

Use the no sdm prefer command to reset the switch to the default desktop 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.

This is an example of an output display when you have changed the template and have not reloaded the switch:

Switch# show sdm prefer 
 The current template is "desktop routing" template. 
 The selected template optimizes the resources in 
 the switch to support this level of features for 
 8 routed interfaces and 1024 VLANs. 

  number of unicast mac addresses:            3K 
  number of igmp groups + multicast routes:   1K 
  number of unicast routes:                   11K 
    number of directly connected hosts:       3K 
    number of indirect routes:                8K 
  number of qos aces:                         0.5K
 number of security aces:                     1K 

 On next reload, template will be "desktop vlan" template.

To return to the default template, use the no sdm prefer global configuration command.

This example shows how to configure a switch with the routing template:

Switch(config)# sdm prefer routing
Switch(config)# end
Switch# reload
Proceed with reload? [confirm]

This example shows how to configure the IPv4-and-IPv6 default template on a desktop switch:

Switch(config)# sdm prefer dual-ipv4-and-ipv6 default
Switch(config)# exit
Switch# reload
Proceed with reload? [confirm]

Displaying the SDM Templates

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

To display the resource numbers supported by the specified template, use the show sdm prefer [access | default | dual-ipv4-and-ipv6 {default | vlan} |routing | vlan] privileged EXEC command.

This is an example of output from the show sdm prefer command that displays the template in use.

Switch# show sdm prefer
 The current template is "desktop default" template.
 The selected template optimizes the resources in
 the switch to support this level of features for
 8 routed interfaces and 1024 VLANs.

  number of unicast mac addresses:             6K
  number of igmp groups + multicast routes:    1K
  number of unicast routes:                    8K
    number of directly connected hosts:        6K
    number of indirect routes:                 2K
  number of policy based routing aces:         0
  number of qos aces:                          0.5K
  number of security aces:                     1K

This is an example of output from the show sdm prefer routing command entered on a desktop switch:

Switch# show sdm prefer routing
"desktop routing" template:
 The selected template optimizes the resources in
 the switch to support this level of features for
 8 routed interfaces and 1024 VLANs.

  number of unicast mac addresses:             3K
  number of igmp groups + multicast routes:    1K
  number of unicast routes:                    11K
    number of directly connected hosts:        3K
    number of indirect routes:                 8K
  number of policy based routing aces:         0.5K
  number of qos aces:                          0.5K
  number of security aces:                     1K

This is an example of output from the show sdm prefer dual-ipv4-and-ipv6 routing command entered on a desktop switch:

Switch# show sdm prefer dual-ipv4-and-ipv6 routing
 The current template is "desktop IPv4 and IPv6 routing" template.
 The selected template optimizes the resources in  the switch to support this level of
 features for 8 routed interfaces and 1024 VLANs.

  number of unicast mac addresses:                  1.5K
  number of IPv4 IGMP groups + multicast routes:    1K
  number of IPv4 unicast routes:                    2.75K
    number of directly-connected IPv4 hosts:        1.5K
    number of indirect IPv4 routes:                 1.25K
  number of IPv6 multicast groups:                  1K
  number of directly-connected IPv6 addresses:      1.5K
  number of indirect IPv6 unicast routes:           1.25K
  number of IPv4 policy based routing aces:         0.25K
  number of IPv4/MAC qos aces:                      0.5K
  number of IPv4/MAC security aces:                 0.5K
  number of IPv6 policy based routing aces:         0.25K
  number of IPv6 qos aces:                          0.5K
  number of IPv6 security aces:                     0.5K