Summary
Now that you have completed this chapter, you should a have a firm understanding of the following concepts:
  • The Cisco multilayer switching implementation consists of a Multilayer Switching-Switching Engine, a Multilayer Switching-Route Processor, and a Multilayer Switching Protocol.
  • The MLS-RP uses multicast Layer 3-hello messages to inform the MLS-SE of the MAC addresses that are participating in MLS, access list information, and routing table updates and changes.
  • The MLS-SE maintains a cache for MLS flows and stores statistics for each flow.
  • MLS-SE distinguishes the MAC address entries of each MLS-RP by assigning an XTAG value to these addresses.
  • To create an MLS cache entry, the MLS-SE must detect both the candidate and enable packet for a specific flow.
  • The MLS-SE uses flow mask modes to determine how MLS entries are created in the MLS cache. MLS-SE supports only one flow mask for all MLS-RPs that are serviced by the MLS-SE.
  • Access lists affect how MLS cache entries are created and maintained.
  • MLS is enabled by default on the Catalyst series switches that support Layer 3 switching.
  • When Layer 3 switching is enabled, the MLS-RP still runs all the routing protocols and maintains a real-time routing table. Changes to the routing table may affect the behavior of MLS.
  • MLS is enabled by default without any MLS configuration on the Catalyst 6000 Series Switch with the MSFC or MSFC II.