SDM (Switching Database Manager) is used on Cisco Catalyst switches to manage the memory usage of the TCAM. For example, a switch that is only used for switching won’t require any memory to store IPv4 routing information. On the other hand, a switch that is only used as a router won’t need much memory to store MAC addresses.
Available templates:
• Access—The access template maximizes system resources for access control lists (ACLs) to
accommodate a large number of ACLs.
• Default—The default template gives balance to all functions.
• Routing—The routing template maximizes system resources for IPv4 unicast routing, typically
required for a router or aggregator 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
Note: On switches running the LAN base feature set, routing values shown in the templates are not valid.
SDM templates for IPv4
SDM templates for Dual Stack IPv4 and IPv6 operation
Configuration examples
Changing SDM template:
Switch(config)# sdm prefer routing Switch(config)# end Switch# reload
This example shows how to configure the IPv4-and-IPv6 default template:
Switch(config)# sdm prefer dual-ipv4-and-ipv6 default Switch(config)# exit Switch# reload
To see current template and resource allocation:
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.
For more information check Cisco documentation: