Because 192.1.1.0 would set your initial starting bits.  Once you put your
"starting point" in place and then apply a mask (which tells you which bits
can change and which ones cannot) then the results you get will be
different!
 
HTH,
 


Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE-M
#153, JNCIS-ER, CISSP, et al.
CCSI/JNCI-M/JNCI-ER
VP - Technical Training - IPexpert, Inc.
IPexpert Sr. Technical Instructor

A Cisco Learning Partner - We Accept Learning Credits!

[EMAIL PROTECTED]

 

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  _____  

From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of GAURAV MADAN
Sent: Saturday, January 26, 2008 12:39 PM
To: Ralph Olsen
Cc: [email protected]
Subject: Re: [OSL | CCIE_RS] Wildcard Q


Hi 
 
Perfect explanation . We want 
 
192.1.1.1
192.1.3.1
192.1.5.1
192.1.7.1
192.1.9.1
 
This will make 192.1.1.1  0.0.14.0 . Which is why we write
 
access-list 1 permit 192.1.1.1 0.0.14.0 
 
Can any one comment on why they have written 192.1.1.0  0.0.14.0 instead of
192.1.1.1  0.0.14.0
 
Gaurav Madan.

 
On 1/26/08, Ralph Olsen <[EMAIL PROTECTED]> wrote: 

Hi Khalid,

You don't care about the 1st, 2nd and 4th octet, because that will be 0
as it doesn't change.
You will have the 3rd octet being
1
3
5
7
9

If you write that in binary you will get

1 00000001
3 00000011
5 00000101
7 00000111
9 00001001

So in the wildcard mask we know that a fixed bit will be marked as a 0
and a wildcard bit will be marked as a 1.

1 00000001
3 00000011
5 00000101
7 00000111
9 00001001

00001110 <-- Bit 5,6,7 (from left to right) is wildcard bits. And
converting 00001110 to decimal will give you 14.

The wildcard mask being 0.0.14.0.

Hint: Use Windows notepad and calculator and write all IP address' in
binary. That will give you a better visual overview.

/Ralph Olsen
> Hi all,
>
> we have 2 routers R1.......> R2 and R1 has 10 Lo interfaces:
> Lo1: 192.1.1.1/24 <http://192.1.1.1/24>
> Lo2: 192.1.2.1/24 <http://192.1.2.1/24>
> Lo3L 192.1.3.1/24 <http://192.1.3.1/24> upto 192.1.10.1/24
> <http://192.1.10.1/24>
>
> we need to configure  R2 to ONLY receive the odd addresses from R1
>
> the answer was:
>
> R2:
> access-list 1 permit 192.1.1.0 <http://192.1.1.0> 0.0.14.0
> <http://0.0.14.0>
> router rip
> distance 255 150.50.17.1 <http://150.50.17.1> 255.255.255.255
> <http://255.255.255.255> 1
> Note: 150.50.17.1 <http://150.50.17.1> is R1
> this Q is from the workbook. Can you give me a full explanation
> about        0.0.14.0 <http://0.0.14.0>
>
> thnx




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