Re: IP cef

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
>>> >>
>>> >>
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>>
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Received on Fri Feb 08 2013 - 16:36:52 ART