Protocol-Independent Features Distributed Cisco Express Forwarding and Load-Balancing Scheme for CEF Traffic , on page 1 Number of Equal-Cost Routing Paths, on page 6 Static Unicast Routes, on page 7 Default Routes and Networks, on page 10 Multiple Next Hops, on page 11 Route Maps to Redistribute Routing Information, on page 12 Policy-Based Routing, on page 19 Filtering Routing Information, on page 23 Managing Authentication Keys, on page 27 Feature History for Protocol-Independent Features, on page 29 Distributed Cisco Express Forwarding and Load-Balancing Scheme for CEF Traffic The following sections provide information about distributed Cisco express forwarding (CEF) and load-balancing scheme for CEF traffic.
Restrictions for Configuring a Load-Balancing Scheme for CEF Traffic • You must globally configure load balancing on device or device stack members in the same way. • Per-packet load balancing for CEF traffic is not supported. Information About Cisco Express Forwarding Cisco Express Forwarding (CEF) is a Layer 3 IP switching technology used to optimize network performance. CEF implements an advanced IP look-up and forwarding algorithm to deliver maximum Layer 3 switching performance. CEF is less CPU-intensive than fast switching route caching, allowing more CPU processing power to be dedicated to packet forwarding. In a switch stack, the hardware uses distributed CEF (dCEF) in the stack.
In dynamic networks, fast switching cache entries are frequently invalidated because of routing changes, which can cause traffic to be process switched using the routing table, instead of fast switched using the route cache. CEF and dCEF use the Forwarding Information Base (FIB) lookup table to perform destination-based switching of IP packets. Protocol-Independent Features 1