Re: IP cef

There is not, no.

--
Marko Milivojevic - CCIE #18427 (SP R&S)
Senior CCIE Instructor / Managing Partner - IPexpert
On Tue, Feb 12, 2013 at 9:06 AM, Tauseef Khan <tasneemjan_at_googlemail.com> wrote:
> Thanks all for a good discussion. another question on ip cef is that when I
> enable <ip cef distributed> and <ip routing>, I don't see ip cef in output
> of <sh run> or <show run all> on 3550 / 3650 / 3760 switching platforms. I
> know that ip cef is running on these platforms by default as soon as I
> enable ip routing. Is there any way of disabling ip cef on switches?
>
>
> Kind regards
>
> On 9 February 2013 01:34, marc edwards <renorider_at_gmail.com> wrote:
>>
>> Thanks for clarifying Marco. I'm a little red in the face making that
>> mistake.
>>
>> On Fri, Feb 8, 2013 at 4:53 PM, David Prall <dcp_at_dcptech.com> wrote:
>> > After the MFI rewrite there is no Fast Path, you get either CEF or
>> > Process Switching. So 12.4(20)T and beyond are hard pressed to run without
>> > "ip cef" enabled.
>> >
>> > --
>> > http://dcp.dcptech.com
>> >
>> >
>> >> -----Original Message-----
>> >> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On
>> >> Behalf Of Marko Milivojevic
>> >> Sent: Friday, February 08, 2013 7:43 PM
>> >> To: marc edwards
>> >> Cc: Keller Giacomarro; Mohammad Mousa; Tauseef Khan; Cisco
>> >> certification
>> >> Subject: Re: IP cef
>> >>
>> >> MPLS control plane does not require CEF. It's the MPLS forwarding
>> >> plane that requires it. It makes up for an interesting troubleshooting
>> >> :-).
>> >>
>> >> Things change between IOS versions and behave differently on different
>> >> platforms, but I recall that uRPF also needed CEF to work. I'm
>> >> positive that ZBF needs it, as well (never tried it with CEF off
>> >> though - feel free). On switches for example, you cannot turn CEF off
>> >> if you have "ip routing" enabled, as it requires CEF to work.
>> >>
>> >> --
>> >> Marko Milivojevic - CCIE #18427 (SP R&S)
>> >> Senior CCIE Instructor / Managing Partner - IPexpert
>> >>
>> >> On Fri, Feb 8, 2013 at 4:36 PM, marc edwards <renorider_at_gmail.com>
>> >> wrote:
>> >> > Marko,
>> >> >
>> >> > Thanks for chiming in. I am interested to know what other control
>> >> > protocols on blue print rely on CEF aside from MPLS?
>> >> >
>> >> > Marc
>> >> >
>> >> > On Fri, Feb 8, 2013 at 3:39 PM, Marko Milivojevic
>> >> > <markom_at_ipexpert.com>
>> >> wrote:
>> >> >> What if "ip routing" was disabled on routers? How about if escape
>> >> >> character was set to "space", etc?  Paranoia, or "I'll always do
>> >> >> this
>> >> >> in a case they're playing games" will not get you very far in the
>> >> >> lab
>> >> >> :-).
>> >> >>
>> >> >> I recommend you do what's needed, no less, no more. If CEF is turned
>> >> >> off, turn it on if you need it, otherwise, why do you care if it was
>> >> >> turned off? :-)
>> >> >>
>> >> >> --
>> >> >> Marko Milivojevic - CCIE #18427 (SP R&S)
>> >> >> Senior CCIE Instructor / Managing Partner - IPexpert
>> >> >>
>> >> >> On Fri, Feb 8, 2013 at 1:30 PM, Keller Giacomarro
>> >> >> <keller.g_at_gmail.com>
>> >> wrote:
>> >> >>> I have a pre-defined set of commands I run on all my configuration-
>> >> section
>> >> >>> devices before I start the section.
>> >> >>>
>> >> >>> ***
>> >> >>> ip cef (doesn't work on switches without 'ip routing' enabled)
>> >> >>> ip classless
>> >> >>> ip subnet-zero
>> >> >>> ***
>> >> >>>
>> >> >>> My logic is -- If any of these are disabled, it's most likely going
>> >> >>> to be a
>> >> >>> purposeful 'break' that you have to fix.  If they want them to stay
>> >> >>> disabled, they'll tell you in the questions.  Either way, it
>> >> >>> doesn't hurt
>> >> >>> you to run all three by default on all devices.
>> >> >>>
>> >> >>> One that I DON'T run is 'ip routing'.  It's not a given that all
>> >> >>> switches
>> >> >>> will be running routing protocols, and when you enable IP routing
>> >> >>> it
>> >> >>> disables the default-gateway, which means adding a static route.
>> >> >>> This is
>> >> >>> probably not allowed in your lab.
>> >> >>>
>> >> >>> I have another tip for the troubleshooting section.  I put this
>> >> >>> text into
>> >> >>> notepad and copy-paste it into every device I open as I open them.
>> >> >>>
>> >> >>> ***
>> >> >>> conf t
>> >> >>> logging con debug
>> >> >>> end
>> >> >>> copy running-config nvram:original.cfg
>> >> >>>
>> >> >>> n
>> >> >>>
>> >> >>>
>> >> >>> ***
>> >> >>>
>> >> >>> First, this ensures I can see all logging outputs.  If it's the
>> >> >>> first time
>> >> >>> I've accessed the device, the config is backed up to
>> >> >>> nvram:original.cfg,
>> >> >>> and the 'n' will be an invalid command.  If it's NOT the first time
>> >> >>> I've
>> >> >>> accessed the device, the newline and the n means original.cfg will
>> >> >>> NOT
>> >> get
>> >> >>> overwritten (answers 'no' to 'do you want to overwrite').  I save
>> >> >>> to
>> >> nvram:
>> >> >>> instead of flash: just in case their IOU instances do not have a
>> >> >>> flash --
>> >> >>> all devices have nvram.
>> >> >>>
>> >> >>> A quick 'end' and then 'wr' before I close ANY window ensures that
>> >> >>> all
>> >> my
>> >> >>> work gets saved too.
>> >> >>>
>> >> >>> This works great for me, what is your strategy?
>> >> >>>
>> >> >>> Keller Giacomarro
>> >> >>> keller.g_at_gmail.com
>> >> >>>
>> >> >>>
>> >> >>> On Fri, Feb 8, 2013 at 11:34 AM, marc edwards <renorider_at_gmail.com>
>> >> wrote:
>> >> >>>
>> >> >>>> I can think of at least one control protocol on the blueprint that
>> >> >>>> won't work w/out CEF (MPLS). Can anyone else add to the list?
>> >> >>>>
>> >> >>>> Marc
>> >> >>>>
>> >> >>>> On Fri, Feb 8, 2013 at 8:03 AM, Mohammad Mousa <mohd-
>> >> mousa_at_hotmail.com>
>> >> >>>> wrote:
>> >> >>>> > Tauseef,
>> >> >>>> >
>> >> >>>> > I think you've to enable them, because some of the services
>> >> >>>> > won't
>> >> work
>> >> >>>> well unless you enable IP CEF/IPV6 CEF, and I think you won't get
>> >> >>>> the
>> >> >>>> complete mark unless you put these commands.
>> >> >>>> >
>> >> >>>> > HTH,
>> >> >>>> >
>> >> >>>> > -Mohammad Mousa
>> >> >>>> > CCIE #36990
>> >> >>>> >
>> >> >>>> >> Date: Fri, 8 Feb 2013 15:33:50 +0000
>> >> >>>> >> Subject: IP cef
>> >> >>>> >> From: tasneemjan_at_googlemail.com
>> >> >>>> >> To: ccielab_at_groupstudy.com
>> >> >>>> >>
>> >> >>>> >> If in the lab ip cef is disabled on the routers and I enable ip
>> >> >>>> >> cef /
>> >> >>>> ipv6
>> >> >>>> >> cef on routers, will I lose marks for that, as over
>> >> >>>> >> configuration.
>> >> >>>> Without
>> >> >>>> >> ip cef every thing will be process switched but still all the
>> >> >>>> >> routing
>> >> >>>> will
>> >> >>>> >> work as normal. Appreciate if someone could explain?
>> >> >>>> >> Regards
>> >> >>>> >>
>> >> >>>> >>
>> >> >>>> >> Blogs and organic groups at http://www.ccie.net
>> >> >>>> >>
>> >> >>>> >>
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