From: Deji Steve-Fagbemi (deji500@hotmail.com)
Date: Thu Feb 08 2007 - 08:08:42 ART
Hi All,
I have figured it out by writing it all out in binary. The problem is that
in an exam situation how do you quickly figure out where to start from.
I have looked at the binary of 197 (11000101) and I know that one must only
allow 00000000 to 11000101. How do you start?
Thanks
This is how I figured it out:
0.0.0.0/1 le 32 will match all numbers whose first digit is 0|xxxxxx, hence
0 - 127
128.0.0.0/2 le 32 will match all numbers whose first two digits are
10|xxxxxx, hence 128 - 191
192.0.0.0/6 le 32 will match all numbers whose first six digits are
110000|xx, hence 192 - 195
196.0.0.0/7 le 32 will match all numbers whose first seven digits are
1100010|x, hence 196 - 197
Where x is any number
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Deji
Steve-Fagbemi
Sent: Thursday, February 08, 2007 10:18 AM
To: 'Manjeet Chawla'; 'Victor Cappuccio'
Cc: swm@emanon.com; ccielab@groupstudy.com
Subject: RE: Route Filtering using Prefix Lis
Scott, Manjeet or anyone else with a good grasp of prefix-lists,
I am struggling really hard to understand the prefix-lists proposed by
Scott.
I have a basic understanding of prefix-lists. I can match routes with a
prefix-list but I can not get the ones proposed by Scott. What if it were
all routes below 161.0.0.0/8?
Someone please help.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Manjeet Chawla
Sent: Tuesday, February 06, 2007 4:13 AM
To: Victor Cappuccio
Cc: swm@emanon.com; ccielab@groupstudy.com
Subject: Re: Route Filtering using Prefix Lis
198.0.0.0/8 is probably not the right answer as it only covers the
"198.0.0.0 - 198.255.255.255"
whereas the question (as I read it) is asking for "0.0.0.0 -
197.255.255.255" range as reflecting in Scott's reply.
-Manjeet
Victor Cappuccio wrote:
> Hi Manjeet
>
> He made it sound like 0-197 in what he was asking
>
> >
> > Any idea hwo we can have route only from 1-197 as the first Octet.
> >
>
> But
>
> >
> > I have a situation where i have to allow all prefixes below
> 198.0.0.0/8 <http://198.0.0.0/8>.
> >
>
> So the question was for the first one or the second one? So Scott
> answered it the Second one and I answered the first one
>
> Thanks
>
> Victor.-
>
>
> On 2/5/07, *secondie* <secondie@gmail.com <mailto:secondie@gmail.com>>
> wrote:
>
> Victor, I think allows all 198.0.0.0/8 <http://198.0.0.0/8> LE 32
> allows only 198.0.0.0 <http://198.0.0.0> -
> 198.255.255.255 <http://198.255.255.255> and LE 32 allows any
> subnet mask in the range mentioned.
>
> Ahmed wants all the subnet from 1-197 in the first octet to be
> permitted
> through :-)
>
> -Manjeet
> CCIE # 5591 (R&S/Security)
>
>
>
>
>
> Victor Cappuccio wrote:
> > Hi Scott,
> >
> > What about this prefix-list
> >
> > permit 198.0.0.0/8 <http://198.0.0.0/8> le 32
> >
> > Thanks
> > Victor.-
> >
> > -----Mensaje original-----
> > De: nobody@groupstudy.com <mailto:nobody@groupstudy.com> en
> nombre de Scott Morris
> > Enviado el: lun 05/02/2007 13:12
> > Para: Ahmed Mohiuddin; ccielab@groupstudy.com
> <mailto:ccielab@groupstudy.com>
> > Asunto: RE: Route Filtering using Prefix List
> >
> > 0.0.0.0/1 <http://0.0.0.0/1> le 32
> > 128.0.0.0/2 <http://128.0.0.0/2> le 32
> > 192.0.0.0/6 <http://192.0.0.0/6> le 32
> > 196.0.0.0/7 <http://196.0.0.0/7> le 32
> >
> > HTH,
> >
> >
> > Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider)
> #4713, JNCIE
> > #153, CISSP, et al.
> > CCSI/JNCI-M/JNCI-J
> > IPexpert VP - Curriculum Development
> > IPexpert Sr. Technical Instructor
> > smorris@ipexpert.com <mailto:smorris@ipexpert.com>
> > http://www.ipexpert.com
> >
> >
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com <mailto:nobody@groupstudy.com>
> [mailto:nobody@groupstudy.com <mailto:nobody@groupstudy.com>] On
> Behalf Of
> > Ahmed Mohiuddin
> > Sent: Sunday, February 04, 2007 11:45 PM
> > To: ccielab@groupstudy.com <mailto:ccielab@groupstudy.com>
> > Subject: Route Filtering using Prefix List
> >
> > Hi All,
> >
> > I have a situation where i have to allow all prefixes below
> 198.0.0.0/8 <http://198.0.0.0/8>.
> >
> > I am trying to use prefix list to accomplish this but does nto
> seem to help.
> >
> > Any idea hwo we can have route only from 1-197 as the first Octet.
> >
> > Thanks
> > Ahmed
> >
> >
> >
> >
>
This archive was generated by hypermail 2.1.4 : Thu Mar 01 2007 - 07:38:46 ART