Solved

Cisco router ip cef

Posted on 2011-09-28
8
3,051 Views
Last Modified: 2012-05-12
I am migrating my config from an old Cisco router to a ASR 1001.  

Part of the config I am migrating over it not coming over, and it is a process I have never heard about.

ip cef - it is asking for additional options that I am unfamiliar with

Therefore, when I go to configure my interface, it states :

in Interface GigabitEthernet 0/0/0
        ip nbar protocol-discovery - because of the ip cef cmd issue
                       no ip mroute-cache - says to use mibs instead ?  The above command is    deprecated. Use MFIB commands instead.

What is this IP CEF (from a knowledge learning perspective)?  And what is the correct attribute that I should add to the end of this cmd ?
0
Comment
Question by:Elemental12
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
8 Comments
 
LVL 18

Expert Comment

by:jmeggers
ID: 36806243
CEF is Cisco Express Forwarding, basically an advanced switching technology.  It used to have to be enabled, but now it's required for a lot of other technologies (e.g., MPLS) so it should be on by default in newer software.  I'm not clear on your issue -- are you saying you're getting an error because it's not enabled?  Did you have the "ip cef" command present in your old router?

MFIB is the multicast forwarding information base, which has apparently replaced the older command.
0
 
LVL 6

Expert Comment

by:Sanjeevloke
ID: 36813603
Advanced version of caching..
config t
int f0/0
ip route-cache cef

0
 

Author Comment

by:Elemental12
ID: 36815171
ip cef was present on the old router, in the actual config.  I am not sure if it is one of those default hidden cmds in this newer cisco IOS.

Sanjeevloke, it took the cmd.  Perhaps it changed from a global configuration cmd on all interfaces to a cmd that is to be entered on just the interface that would be doing this ?
0
Free NetCrunch network monitor licenses!

Only on Experts-Exchange: Sign-up for a free-trial and we'll send you your permanent license!

Here is what you get: 30 Nodes | Unlimited Sensors | No Time Restrictions | Absolutely FREE!

Act now. This offer ends July 14, 2017.

 

Author Comment

by:Elemental12
ID: 36815206
also, I used no ip mfib cef input and no ip mfib cef output to cover the no ip mroute-cache depricated cmd; anything else you guys think I need ?
0
 
LVL 6

Expert Comment

by:Sanjeevloke
ID: 36815497
you  can enable cef globally
config t#
#ip cef

it doesn't harm anything...
0
 

Author Comment

by:Elemental12
ID: 36815554
When I try to do that, it comes up with option :

ip cef ?
  accounting          Enable CEF accounting
  distributed         Distributed Cisco Express Forwarding
  load-sharing        Load sharing
  optimize            Optimizations
  traffic-statistics  Enable collection of traffic statistics

Not sure which options to use.  Looking at my old router, it only states "ip cef" in the global (not interface) cfg.  Looks like in the older IOS, you can just hit enter, without selecting options, but in the new IOS it requires you to pick one, or perhaps all.
0
 

Author Comment

by:Elemental12
ID: 36891234
anyone with more information about which options I should use/configure ?

Thanks in advance
0
 
LVL 6

Accepted Solution

by:
Sanjeevloke earned 500 total points
ID: 36891510
ip cef distributed  you should use...

Enable dCEF when you want your line cards to perform express forwarding so that the route processor can handle routing protocols or switch packets from legacy interface processors.
0

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Quality of Service (QoS) options are nearly endless when it comes to networks today. This article is merely one example of how it can be handled in a hub-n-spoke design using a 3-tier configuration.
Shadow IT is coming out of the shadows as more businesses are choosing cloud-based applications. It is now a multi-cloud world for most organizations. Simultaneously, most businesses have yet to consolidate with one cloud provider or define an offic…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…
There's a multitude of different network monitoring solutions out there, and you're probably wondering what makes NetCrunch so special. It's completely agentless, but does let you create an agent, if you desire. It offers powerful scalability …

718 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question