From: Dillon Yang (gzdillon@hotmail.com)
Date: Tue Mar 29 2005 - 13:09:45 GMT-3
Hi,
revision:
> 1=0001
> 2=0010
> 4=0100
> 5=0101
> so, /21 over the 4 route,
> 4.0/23 over the 4.0 and 5.0
> 1.0/22 over the 0.0 , 1.0 and 2.0 and 3.0
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
BTW
xxxxxxxx.xxxxxxxx.0000 0100.0
xxxxxxxx.xxxxxxxx.0000 0101.0
__________________________^ difference begin here!!! its /23
HTH
dillon
----- Original Message -----
From: "Lee Donald" <Lee.Donald@t-systems.co.uk>
To: "Dillon Yang" <gzdillon@hotmail.com>; "Lee Donald" <Lee.Donald@t-systems.co.uk>
Cc: "Group Study" <ccielab@groupstudy.com>
Sent: Wednesday, March 30, 2005 12:05 AM
Subject: RE: IP Prefix-list Question
> Dillon,
>
> I have already drawn out the zero's and ones but I can't see /23 ?
>
> How does /23 work ?
>
>
>
> -----Original Message-----
> From: Dillon Yang [mailto:gzdillon@hotmail.com]
> Sent: 29 March 2005 16:58
> To: Lee Donald
> Cc: Group Study
> Subject: Re: IP Prefix-list Question
>
> Hi, lee:
>
> 1=0001
> 2=0010
> 4=0100
> 5=0101
> so, /21 over the 4 route,
> 4.0/23 over the 4.0 and 5.0
> 1.0/23 over the 1.0 and 2.0
> HTH
> dillon
>
>
> ----- Original Message -----
> From: "Lee Donald" <Lee.Donald@t-systems.co.uk>
> To: "Dillon Yang" <gzdillon@hotmail.com>; "Sundar Palaniappan"
> <sundarp@gmail.com>
> Cc: "Group Study" <ccielab@groupstudy.com>
> Sent: Tuesday, March 29, 2005 11:48 PM
> Subject: RE: IP Prefix-list Question
>
>
> > Guys,
> >
> > I have tried this and it only lets subnets 4 & 5 in ?
> >
> > Also I was after the methlogy behind it so I can work it out for myself,
> you
> > just telling me the answer is only part of it.
> >
> > I don't quite understand the /23 and the le 24 ge 24 bits ?
> >
> >
> >
> > -----Original Message-----
> > From: Dillon Yang [mailto:gzdillon@hotmail.com]
> > Sent: 29 March 2005 16:41
> > To: Sundar Palaniappan
> > Cc: Group Study
> > Subject: Re: IP Prefix-list Question
> >
> > Yes, Sundar:
> >
> > The task is just the SIX routes!
> > so feel free.
> > I think you'd not overthink the unknown subnet as 3, 6, 7.
> > Any expert advice?
> >
> > HTH
> > dillon
> >
> >
> > ----- Original Message -----
> > From: "Sundar Palaniappan" <sundarp@gmail.com>
> > To: "Philippe Couture" <philippecouture@gmail.com>
> > Cc: <ccielab@groupstudy.com>; <Lee.Donald@t-systems.co.uk>
> > Sent: Tuesday, March 29, 2005 11:28 PM
> > Subject: Re: IP Prefix-list Question
> >
> >
> > > Dillon,
> > >
> > > You are allowing subnets 3, 6, 7 that aren't part of the requirment.
> > >
> > > Lee's requirement is minimum number of lines to be used. Your solution
> > > would be correct if only one line is to be used to accomplish that.
> > >
> > > Not sure if Cisco would consider your solution correct.
> > >
> > > --Sundar Palaniappan
> > >
> > >
> > > On Tue, 29 Mar 2005 10:23:04 -0500, Sundar Palaniappan
> > > <sundarp@gmail.com> wrote:
> > > > My bad.
> > > >
> > > > Last statement should be,
> > > >
> > > > ip prefix-list cisco permit 192.54.4.0/23 ge 24 le 24
> > > >
> > > > What you are doing is, you are permiting everything after
> > > > 192.54.4.0/23 but the subnet mask has to be 24 bits always.
> > > >
> > > > If you don't use le 24 then you are allowing prefixes with shorter
> > > > mask i.e .25, .26 etc to be advertised.
> > > >
> > > > In the lab, I wouldn't take a chance and just nail it down.
> > > >
> > > > HTH,
> > > > Sundar Palaniappan
> > > >
> > > >
> > > > On Tue, 29 Mar 2005 10:03:43 -0500, Philippe Couture
> > > > <philippecouture@gmail.com> wrote:
> > > > > Sundar,
> > > > >
> > > > > Wouldn't the third line need to be "ip prefix-list cisco permit
> > > > > 192.54.4.0/23 ge 24" ?
> > > > >
> > > > > I could be wrong but I think that since you don't care about the
> 24th
> > > > > bit (i.e. you want to match .4 and .5), you would use a mask length
> of
> > > > > 23, and the "ge 24" says to use prefix lengths of 24 or more. If you
> > > > > want to really only allow 24 and nothing longer, you would also need
> > > > > to add "le 24".
> > > > >
> > > > > Phil
> > > > >
> > > > >
> > > > > On Tue, 29 Mar 2005 09:54:59 -0500, Sundar Palaniappan
> > > > > <sundarp@gmail.com> wrote:
> > > > > > Lee,
> > > > > >
> > > > > > Or you could you configure
> > > > > >
> > > > > > ip prefix-list cisco permit 192.54.1.0/24
> > > > > > ip prefix-list cisco permit 192.54.2.0/24
> > > > > > ip prefix-list cisco permit 192.54.4.0/24 ge 23
> > > > > >
> > > > > > Either way you need 3 statements atleast.
> > > > > >
> > > > > > HTH,
> > > > > > Sundar Palaniappan
> > > > > >
> > > > > > On Tue, 29 Mar 2005 15:19:12 +0100, Lee Donald
> > > > > > <Lee.Donald@t-systems.co.uk> wrote:
> > > > > > > I'm having trouble understanding IP Prefix-lists can anybody
> > clarify this
> > > > > > > for me?
> > > > > > >
> > > > > > > I have this question; use a prefix list with the minimum amount
> of
> > lines to
> > > > > > > allow 1,2,4,5 networks in.
> > > > > > >
> > > > > > > 192.54.1.0/24
> > > > > > >
> > > > > > > 192.54.2.0/24
> > > > > > >
> > > > > > > 192.54.4.0/24
> > > > > > >
> > > > > > > 192.54.5.0/24
> > > > > > >
> > > > > > > 192.54.21.0/24
> > > > > > >
> > > > > > > 192.54.22.0/24
> > > > > > >
> > > > > > > I have 3 lines, 2 denying 21, and 22, the other allowing
> > everything.
> > > > > > >
> > > > > > > Is this the minimum?, if not why not?
> > > > > > >
> > > > > > > Thanks in advance for your help.
> > > > > > >
> > > > > > > Regards
> > > > > > >
> > > > > > > Lee Donald.
> > > > > > >
> > > > > > >
> > _______________________________________________________________________
> > > > > > > Subscription information may be found at:
> > > > > > > http://www.groupstudy.com/list/CCIELab.html
> > > > > >
> > > > > >
> > _______________________________________________________________________
> > > > > > Subscription information may be found at:
> > > > > > http://www.groupstudy.com/list/CCIELab.html
> > >
> > > _______________________________________________________________________
> > > Subscription information may be found at:
> > > http://www.groupstudy.com/list/CCIELab.html
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Sun Apr 03 2005 - 17:56:54 GMT-3