Cisco Express Forwarding --A scalable, distributed, Layer 3 switching solution designed to meet the future performance requirements of the Internet and enterprise networks.
forwarding adjacency --A traffic engineering link (or LSP) into an IS-IS/OSPF network.
IGP --Interior Gateway Protocol. Internet protocol used to exchange routing information within an autonomous system. Examples of common IGPs include Interior Gateway Routing Protocol (IGRP), Open Shortest Path First ( OSPF), and Routing Information Protocol (RIP).
IS-IS --Intermediate System-to-Intermediate System. Open System Interconnection (OSI) link-state hierarchical routing protocol whereby Intermediate System (IS) routers exchange routing information based on a single metric to determine network topology.
label switched path (LSP) --A sequence of hops (R0...Rn ) in which a packet travels from R0 to Rn through label switching mechanisms. A switched path can be chosen dynamically, based on normal routing mechanisms, or through configuration.
label switched path (LSP) tunnel --A configured connection between two routers, using label switching to carry the packets.
MPLS-- Multiprotocol Label Switching. A switching method that forwards IP traffic using a label. This label instructs the routers and the switches in the network where to forward the packets based on preestablished IP routing information.
OSPF --Open Shortest Path First. A link-state, hierarchical IGP routing algorithm proposed as a successor to RIP in the Internet community. OSPF features include least-cost routing, multipath routing, and load balancing. OSPF was derived from an early version of the IS-IS protocol. See also IS-IS.
SPF --Shortest Path First. A routing algorithm used as the basis for OSPF operations. When an SPF router is powered up, it initializes its routing-protocol data structures and then waits for indications from lower-layer protocols that its interfaces are functional.
TLV --type, length, value. A block of information embedded in Cisco Discovery Protocol advertisements.
traffic engineering --The techniques and processes used to cause routed traffic to travel through the network on a path other than the one that would have been chosen if standard routing methods had been applied.
traffic engineering tunnel --A label switched tunnel that is used for traffic engineering. Such a tunnel is set up through means other than normal Layer 3 routing; it is used to direct traffic over a path different from the one that Layer 3 routing would cause the tunnel to take.