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What is the difference between process switching and fast CEF switching?
Process switching requires the CPU to be personally involved with every forwarding decision. Fast switching still uses the CPU, but after a packet has been forwarded, information about how to reach the destination is stored in a fast-switching cache.
What is a benefit of CEF switching?
Function. CEF is mainly used to increase packet switching speed by reducing the overhead and delays introduced by other routing techniques. CEF consists of two key components: The Forwarding Information Base (FIB) and adjacencies.
What are two characteristics of Cisco Express Forwarding CEF?
Cisco Express Forwarding (CEF) builds a forwarding information base (FIB) and an adjacency table to be able to route packets quicker than traditional packet forwarding methods can.
What does CEF stand for as it relates to Cisco routers?
Cisco Express Forwarding
Cisco Express Forwarding (CEF) switching is a proprietary form of scalable switching intended to tackle the problems associated with demand caching. With CEF switching, the information which is conventionally stored in a route cache is split up over several data structures.
What is the process of switching?
Process switching refers to the process by which the router’s CPU or processor is directly involved in the forwarding decision. As a packet is process-switched through the router, its CPU is responsible of choosing the appropriate process to handle the packet and scheduling the running of the process.
What kind of process is switching?
At some time, a running process is interrupted and the operating system assigns another process to the running state and turns control over that process. A process switch may occur any time that the operating system has gained control from the currently running process.
How is CEF switching triggered?
Like fast switching, CEF builds a Forwarding Information Base (FIB), and an adjacency table. However, the table entries are not packet-triggered like fast switching but change-triggered such as when something changes in the network topology.
What are three types of IP packets that require process switching?
In general, three switching methods are available in Cisco IOS today:
- Process switching: Packets are processed and forwarded directly by the router CPU.
- Fast switching: Packets are forwarded in the CPU interrupt, using cache entries created by process switching.
What does Cisco CEF do?
Introduction. Cisco Express Forwarding (CEF) is a packet-switching technique used within Cisco routers. The main purpose of CEF is to optimize the forwarding of packets and increase the packet switching speed.
What events can trigger a process switch?
There are three potential triggers for a context switch:
- Multitasking.
- Interrupt handling.
- User and kernel mode switching.
- Hardware vs. software.
Why is Task Switching important?
Task switching allows a person to rapidly and efficiently adapt to different situations. It is often studied by cognitive and experimental psychologists, and can be tested experimentally using tasks like the Wisconsin Card Sorting Test.