Chapter 9. MPLS
Multiprotocol Label Switching Overview
Multiprotocol Label Switching (MPLS) leverages the efficiency of Cisco Express Forwarding (CEF) and the intelligence provided by IP routing. Remember that CEF allows for the creation of a copy of the routing information base in memory in the Cisco router or switch. This memory-based structure is called the Forwarding Information Base (FIB), and it allows for remarkable packet forwarding times through what traditionally had been much slower devices.
MPLS appends a label to packets. This label can be used for efficient forwarding decisions through an MPLS network. Using MPLS, the Layer 3 header information can be analyzed once as the packet enters the MPLS domain. After this single Layer 3 ...