Re: ACL Summarisation / Decimal/Hexadecimal/Binary Conversion

From: Howard C. Berkowitz (hcb@gettcomm.com)
Date: Mon Aug 23 2004 - 09:35:24 GMT-3


At 10:12 PM +1000 8/23/04, Mathew wrote:
>Hi Group
>
>Can someone give me link or quick steps to do the summarize address
>into few ACLs lines?
>
>Thanks
>
>mathew

Memorize the bit patterns for contiguous ones and zeroes in an octet:

     0000 0000: 0 0000 0000: 0
     0000 0001: 1 1000 0000: 128
     0000 0011: 3 1100 0000: 192
     0000 0111: 7 1110 0000: 224
     0000 1111: 15 1111 0000: 240
     0001 1111: 31 1111 1000: 248
     0011 1111: 63 1111 1100: 252
     0111 1111: 127 1111 1110: 254
     1111 1111: 255 1111 1111: 255

Notice that I have written the binary patterns in groups of 4, which
will correspond to hexadecimal digits should you use them.

To see examples of the various CIDR subnets, look at RFC 1878.

>
>marc van hoof wrote:
>>Just a quick thing - I think that you really need to be able to do this kind
>>of stuff on paper without a conversion chart... if you get a question that
>>asks you to summarize 8 addresses into a single line of an ACL, you're going
>>to want to understand it perfectly.
>>
>>Having said that, if you ALREADY understand it, this conversion chart can
>>speed things up a lot.
>>
>>I just don't think that people should have the opinion of not needing to
>>understand it perfectly just because there's a conversion chart - this is
>>core stuff !!!
>>
>>-marc.
>>
>>>-----Original Message-----
>>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
>>>Tinis, Phillip
>>>Sent: Saturday, 21 August 2004 8:54 AM
>>>To: ccielab@groupstudy.com
>>>Subject: Decimal/Hexadecimal/Binary Conversion Chart on the CD
>>>
>>>http://www.cisco.com/univercd/cc/td/doc/product/tel_pswt/vco_prod/ext_prg/
>>>ex
>>>prb.htm
>>>
>>>Voice/Telephony
>>>- Telephony Applications
>>> - VCO/4K Product Documentation Set
>>> - VCO/4K Extended Programming Reference
>>> - Decimal/Hexadecimal/Binary Conversion
>>>
>>>
>>>Sincerely,
>>>
>>>Phillip Tinis, CCDP CCNP
>>>EDS / ChevronTexaco
>>>4900 Fournace Place
>>>Room 625A
>>>Bellaire, TX 77401
>>>+001 713 432 2546
>>>
>>>_______________________________________________________________________
>>>Please help support GroupStudy by purchasing your study materials from:
>>>http://shop.groupstudy.com
>>>
>>>Subscription information may be found at:
>>>http://www.groupstudy.com/list/CCIELab.html
>>
>>
>>_______________________________________________________________________
>>Please help support GroupStudy by purchasing your study materials from:
>>http://shop.groupstudy.com
>>
>>Subscription information may be found at:
>>http://www.groupstudy.com/list/CCIELab.html
>
>_______________________________________________________________________
>Please help support GroupStudy by purchasing your study materials from:
>http://shop.groupstudy.com
>
>Subscription information may be found at:
>http://www.groupstudy.com/list/CCIELab.html



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