Re: IP cef

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
>> >>
>> >>
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