Describing the Campus Infrastructure Module
What is a multilayer switch?

Multilayer switching is hardware-based switching and routing, integrated into a single platform. In some cases, the frame and packet forwarding operation is handled by the same specialized hardware ASIC and other specialized circuitry. A multilayer switch does everything to a frame and packet that a traditional switch or router does, including the following:

  • Provides multiple simultaneous switching paths
  • Segments broadcast and failure domains
  • Provides destination specific frame forwarding based on Layer 2 information
  • Determines the forwarding path based on Layer 3 information
  • Validates the integrity of the Layer 2 frame and Layer 3 packet via checksums and other methods
  • Verifies packet expiration and updates accordingly
  • Processes and responds to any option information
  • Updates forwarding statistics in the Management Information Base (MIB)
  • Applies security and policy controls, if required
  • Provides optimal path determination
  • The more expensive or sophisticated multilayer switches are modular and support a wide variety of media types and port densities.
  • Has the ability to support QoS
  • Has the ability to support VoIP and in-line power requirements

Because it is designed to handle high-performance LAN traffic, a multilayer switch can be placed anywhere within the network, cost-effectively replacing the traditional switches and routers. Generally, however, a multilayer switch may be more than is required to provide end systems access to network resources.