Re: IP Prefix-List question

Hello Maarten,

Thanks!

What confuse me is that no solution seems to be 100% true.
- if I go with my one line prefix-list solution, than the request with
minimum number of prefix-list is totally fulfilled , but I'm not that
specific in regard to subnets
- if I go with the proposed solution or with yours, then I'm more
specific in regards to subnets matching, but I have more lines in the
prefix-list

It's not a task that I would call it hard to solve, rather a grey area one.

Calin

On 04/03/2012 10:14 AM, Maarten Vervoorn wrote:
> Hi Calin,
>
> The first one has the least prefix-list lines. The second one in the answer
> is a bit strange because it starts with 23 and thwere are no prefixes with
> 23 or 24.
> ip prefix-list ONE seq 5 permit 10.4.0.0/22 ge 23 le 30
> ip prefix-list ONE seq 10 permit 10.4.4.0/22 ge 23 le 28
> For the prefix 10.4.0.0/22 only 23 - 30 prefix lengts are allowed. 23 -
> 28 is not needed if I look at the prefixes. Also 23-25 and 28 is not needed
> in the second line
>
> in 10.4.0.0/21 ge25 le 30, prefixes 28, 29 and 30 are also allowed in the
> 10.4.4.0/22 part and 25 - 27 are allow from the 10.4.0.0/22 part
> But if it comes to prefixes I think I would expect a answer with a prefix
> list as below
> ip prefix-list ONE seq 5 10.4.0.0/22 ge 28 le 30
> ip prefix-list ONE seq 10 10.4.4.0/22 ge 25 le 27
>
> Kind regards,
>
> Maarten Vervoorn
> CCIE#27144
>
>
>
> 2012/4/3 Calin Chiorean <calin_at_engineer.com>
>
>> Hello Nitin,
>>
>> I think I was pretty clear in my e-mail:
>>
>> "I have a task in a preparation Lab for CCIE RS"
>>
>> Preparation Lab = workbook, mock lab, etc; this is what I understand
>> from my phrase.
>>
>> This is not a task from the actual lab. Since I did not sit yet for the
>> latest version (v4 I believe) of the lab, it4s pretty hard to guess the
>> tasks :)
>>
>> Cheers,
>> Calin
>>
>> On 04/03/2012 05:47 AM, nitin shettigar wrote:
>>> Hi Calin,
>>>
>>> The Cisco NDA policy restricts one to discuss any thing which is related
>>> directly to the LAB examination. Hope the Cisco guys don't come running
>>> after you and debar you from the cisco community for life-time.
>>>
>>> regards,
>>>
>>> Nitin
>>>
>>> On Tue, Apr 3, 2012 at 12:59 AM, Calin Chiorean <calin_at_engineer.com
>>> <mailto:calin_at_engineer.com>> wrote:
>>>
>>> Hello,
>>>
>>> I have a task in a preparation Lab for CCIE RS and I would like your
>>> opinion on this.
>>>
>>> I have a number of subnets from which the followings are important
>> for
>>> this task:
>>>
>>> 10.4.1.4/30 <http://10.4.1.4/30>
>>> 10.4.2.8/29 <http://10.4.2.8/29>
>>> 10.4.3.16/28 <http://10.4.3.16/28>
>>> 10.4.4.32/27 <http://10.4.4.32/27>
>>> 10.4.5.64/26 <http://10.4.5.64/26>
>>> 10.4.6.128/25 <http://10.4.6.128/25>
>>>
>>> The other present subnets are something like 10.7.x.x
>>>
>>> The request is to configure a prefix-list with base on:
>>> - allow all subnets in 10.4.0.0
>>> - as specific as possible, I should not allow other prefixes
>>> - minimum number of prefix-lists
>>>
>>> Considering the above one I did
>>> ip prefix-list ONE permit 10.4.0.0/21 <http://10.4.0.0/21> ge 25 le
>> 30
>>>
>>> However the proposed solution is:
>>> ip prefix-list ONE seq 5 permit 10.4.0.0/22 <http://10.4.0.0/22> ge
>>> 23 le 30
>>> ip prefix-list ONE seq 10 permit 10.4.4.0/22 <http://10.4.4.0/22> ge
>> > 23 le 28
>>>
>>> Both solutions are working, nevertheless which one would you choose
>> in
>>> an exam?
>>>
>>> Thanks and cheers,
>>> Calin
>>>
>>>
>>> Blogs and organic groups at http://www.ccie.net
>>>
>>>
>> _______________________________________________________________________
>>> Subscription information may be found at:
>>> http://www.groupstudy.com/list/CCIELab.html
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Tue Apr 03 2012 - 10:35:27 ART