RE: IPV6 Address Summarization - Windows calculator?

From: Joseph Brunner (joe@affirmedsystems.com)
Date: Fri Aug 31 2007 - 13:46:20 ART


You're missing the fact that even though we see "one" and "two" in the ipv6
address you need to know those are indeed HEX numbers not decimal numbers...
so when you convert from hex to binary, remember each one is equal to four
bits in binary. So

1 in hex and 2 in hex is

0001 and 0010

Don't forget padding zeros... if a hex number doesn't use all its ones (and
wont until its "F" which is 1111,

It gets to "hold" the places with padding zeros...

So if you see an ipv6 address with some numbers 0-9 they indeed represent
4-bit hexadecimal values.

Joe

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Cecil Wilson
Sent: Friday, August 31, 2007 11:55 AM
To: Joseph Brunner; Usankin, Andrew; Cisco certification
Subject: RE: IPV6 Address Summarization - Windows calculator?

Can someone tell how we get

      1 2

 00000110

     2 5

 00010101

12 hex = c and 12 bin = 10010

25 hex = 19 and 25 bin = 100101

What am I missing

Thanks for help to shed some light on this

Cecil G. Wilson

IT Network Services

Office: (901) 215-2710

Cell: (901) 601-6201

cecil.wilson@flextronics.com

-----Original Message-----

From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of

Joseph Brunner

Sent: Thursday, August 30, 2007 10:09 PM

To: 'Usankin, Andrew'; 'Cisco certification'

Subject: RE: IPV6 Address Summarization - Windows calculator?

That was me on the phone at the same time... when I hung up, I realized

my mistake (not padding the nibbles with zeros). EACH HEX number is 4

bits Even if in decimal its not. LOL

Yes you can use the windows calc in the lab. Its one of the few

resources available to you...

-J

-----Original Message-----

From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of

Usankin, Andrew

Sent: Thursday, August 30, 2007 4:40 PM

To: Cisco certification

Subject: IPV6 Address Summarization - Windows calculator?

:) In the light of Joseph's mistake I have a question. Can we use

windows calculator in the lab?

12(hex) = 00010010

25(hex) = 00110101

Andrew

-----Original Message-----

From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of

Joseph Brunner

Sent: Thursday, August 30, 2007 1:48 PM

To: 'Sadiq Yakasai'; 'Cisco certification'

Subject: RE: IPV6 Address Summarization

The first 48 bits wont change, agreed?

2001:141:1

2001:141:1

Lets look at the 16 bits of the 128 where have a different value...

12 in hex is shorted from 0012

25 in hex is shorted from 0025

Each XX equals 8 bits

So

00000000

00000000

That means we already have a /56 up to midway through the 4th 16 bit

block...

Now convert each nibble to binary and pad up to /64...

      1 2

 00000110

     2 5

 00010101

00000000000 (11 zero's of similarity in the 4th 16th bit block)

11 + 48 = 59

You are correct it's a /59

Who told you other wise?

-Joe

-----Original Message-----

From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of

Sadiq Yakasai

Sent: Thursday, August 30, 2007 2:56 PM

To: Cisco certification

Subject: IPV6 Address Summarization

Hi Guys,

Please could someone help out a guy here:

I need to summarize these two IPV6 addresses:

2001:141:1:12::/64

2001:141:1:25::/64

I have done it many times over, and what I find to be the summarized

address

is:

2001:141:1::/59

However, an excercise I am doing here says is

2001:141:1::/58

Please can someone confirm if I am right or wrong here?

Thanks!!

Sadiq



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