SDM Templates Concepts

SDM Templates: Concept Notes

This post is part of a series of revision notes I put together and used for studying CCNP Switch concepts. I am now writing them up on this website so that they might be useful to others.

They formed a part of my notes intended to explain concepts in simple terms. I hope they come in use, but as a reminder, please do not use these notes as any indication of what is sufficient for CCNP level understanding.

Let’s get started.

What It Is

  • An SDM Template refers to configuration templates which optimise the use of physical resources on a Cisco Switch
  • They may be configured in order to maximise or minimise specific device features, depending on how the Switch is used in the network

Types of SDM Templates

Access:

  • The access template maximizes system resources for access control lists (ACLs) in order to accommodate a large number of ACLs

Default:

  • The default template gives balance to all functions
  • As the name implies, this is the default template a Switch uses

Routing:

  • The routing template maximizes system resources for IPv4 unicast routing, typically required for a router or aggregator in the center of a network

VLAN:

  • The VLAN template disables routing and supports the maximum number of unicast MAC addresses
  • Typically selected for a Layer 2 switch only
  • If the Switch has to do any routing, it is done in software only, this may cause CPU spikes and degraded performance

Configuration

To configure any of the above templates, we use the ‘sdm prefer’ command in Global Config mode followed by the template name

Any changes to the SDM Template will only take effect after a reload:

Verification

To see the current template a Switch may be using, use the below command:

Revision Flashcard

Last but not least, I have put together a digital flashcard based on my notes.

Please be aware that neither this post nor this flashcard is to be taken as all the information you need to know regarding SDM Templates, it just contains the basics and is intended to be used as a supplement to your own notes and studies.

I hope it helps.

SDM Templates

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