mls...

can this be any more clear...

according to wendell odom in ccie r&s:

http://books.google.com/books?id=WWc38K0R7M8C&pg=PT353&lpg=PT353&dq=mls+odom+cisco+definition&source=bl&ots=wl9avqjuPy&sig=FfKQq1s-ND2lm73jkqX_eYsBEm0&hl=en&sa=X&ei=ukWPT7uON6rd0QHkt5HGDw&ved=0CCkQ6AEwAA#v=onepage&q&f=false

Multilayer Switching (MLS) refers to the process by which a LAN switch, which operates at least at layer 2, also uses logic and protocols from layers other than layer 2 to forward data. The term Layer 3 switching refers specifically to the use of the Layer 3 destination address, compared to the routing table (or equivalent), to make the forwarding decision.

and this from: http://www.networkpcworld.com/2011/03/layer-2-switching-devices-that-forward.html

Multilayer Switching
  
Devices involved in MLS perform the following functions:

• Packets are forwarded in hardware that combines Layer 2, Layer 3, and Layer 4 switching.
• Packets are forwarded at wire speed. 
• The traditional Layer 3 routing function is provided using Cisco Express Forwarding (CEF), in which a database of routes to every destination network is maintained and distributed to switching ASICs for very high forwarding performance.

Cisco switches perform multilayer switching at Layer 3 and Layer 4. At Layer 3, the Catalyst family of switches caches traffic flows based on IP addresses. At Layer 4, traffic flows are cached based on source and destination addresses, in addition to source and destination ports. All switching is performed in hardware, providing equal performance at both Layer 3 and Layer 4 switching.

and finally:

from: http://www.ciscopress.com/articles/article.asp?p=425816

The term multilayer switching refers to the ability of a Catalyst switch to support switching and routing of packets in hardware, with optional support for Layers 4 through 7 switching in hardware as well