I have heard of terms used in Network such as IP CEF and LSR.
The only place where I believe those terms are used is in MPL Wan.
I wonder if these terms (Technology) is used inside the LAN ?

Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

NetExpert Network Solutions Pte LtdTechnical SpecialistCommented:
IP CEF can be used in LAN and most of the peoples are using nowadays in DC and LAN infrastructure.


Kanti PrasadCommented:
Hi jskfan

Yes it uses in LAN

Cisco Express Forwarding operation has two modes one is CEF and the other DCEF.
CEF (Cisco Express Forwarding) is a Layer 3 switching technology. It is otherwise also referred as central Cisco Express Forwarding mode.It enables a Route Processor to perform express forwarding.

DCEF (Distributed Cisco Express Forwarding) uses line cards (such as Versatile Interface Processor (VIP) line cards) to maintain identical copies of the forwarding information base (FIB) and adjacency tables. The line cards perform the express forwarding between port adapters and thus relieves the Route Switch Processor of involvement in the switching operation.

Route Processor is a combination of RIB + FIB + AT

AT (Adjacent Table) Stores forwarding information (outbound interface and MAC header rewrite) for adjacent nodes.

FIB (FIB --forwarding information base) is lookup table to make destination-based switching decisions
RIB (Routing Information Base \ routing table) is a routes repository od Layer 3 reachability information and destination IP addresses or prefixes.

LSR (label switch router) is a Layer 3 router that forwards a packet based on the value of a label encapsulated in the packet.
jskfanAuthor Commented:
Is it used like in L3 Switches ?
to do the routing between Vlans or it is used also in L2 Switches ?
Powerful Yet Easy-to-Use Network Monitoring

Identify excessive bandwidth utilization or unexpected application traffic with SolarWinds Bandwidth Analyzer Pack.

Kanti PrasadCommented:

They are L switches.

L3 switching is hardware-assisted routing in ASICs (VIPs, RPs, TCAMs etc...) using the help of CEF (layer 3 switch)

L3 routing makes routing decisions using the universal/main CPU of the router populating the routing table and forwarding the packets in software.

For intra-VLAN communication, it uses the MAC address table. For extra-VLAN communication, it uses the IP routing table.

A L3 switch does switching and has an identity from the L3 layer which means it can have IP addresses and also do routing.

A L2 switch does switching only using MAC addresses to switch the packets from a port to the destination port  by maintaining a MAC address table so that it can remember which ports have which MAC address associated.
jskfanAuthor Commented:
If I understand you do not configure it on Switches or on routers.?
The only place I saw it configured is on Cisco MPLS, which relies CEF to build FIB,LIB,FLIB
Kanti PrasadCommented:

Yes your are correct. Please look at the below link to get some idea on the configuration


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
jskfanAuthor Commented:
Thanks..I will get back on this later
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.