Solved

Cisco router ip cef

Posted on 2011-09-28
8
3,015 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
How our DevOps Teams Maximize Uptime

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us. Read the use case whitepaper.

 

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

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Connect two buildings 6 57
Etherchannel balancing 10 39
Deny permission ACL 16 47
Cisco HSRP - Do i need more than one WAN IP ? 7 11
AWS has developed and created its highly available global infrastructure allowing users to deploy and manage their estates all across the world through the use of the following geographical components   RegionsAvailability ZonesEdge Locations  Wh…
David Varnum recently wrote up his impressions of PRTG, based on a presentation by my colleague Christian at Tech Field Day at VMworld in Barcelona. Thanks David, for your detailed and honest evaluation!
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

733 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