From: syed hafiz (mail4hafiz@gmail.com)
Date: Sat Aug 30 2008 - 16:40:52 ART
Thanks for tht reply anant tht solved my issue ,
but continuing to tht question y have u made the last octet of the wild
card mask '0'
as i was stuck abt tht. is tht includes for XOR operation as well
thanks
ashhy
On 8/30/08, Fahad Khan <fahad.khan@gmail.com> wrote:
>
> The actual game is of 3rd octat in this case.
>
> starting IP = x.x.4.0
> ending IP = x.x.15.0
>
> Four most significant bits are common in the 3rd octat i.e 0000
>
> so we have 0100 (4) and 1111(15) for our play
>
> now for calculating IP in accesslist,
>
> perform AND operation in between, 0100 and 1111
>
> 0100
> 1111
> -------
> 0100 = 4
> -------
> Hence, the IP is decided now as x.x.4.0
>
> Now for calculation of wildcard mask, perform XOR operation
>
> 0100
> 1111
> -------
> 1011 = 11
> -------
>
> Rules for XOR:
>
> - For same number of inputs output is 0 otherwise 1
> - For even number of 1s output is 0 while for odd number of 1s output is 1.
>
> hense you get the ACL as:
>
> permit x.x.4.0 0.0.11.0
>
>
> HTH
> On 8/30/08, ashhy <mail4hafiz@gmail.com> wrote:
>>
>> Hi all
>> i want to know how to get this right acl for the below mentioned question
>>
>> i can use only one acl to do this ,i am getting 16 routes of class c
>> from xxx.xxx.1.0 to xxx.xxx.16.0
>> from backbone out of which i should allow only
>>
>> xxx.xxx.4.0
>> xxx.xxx.5.0
>> xxx.xxx.6.0
>> xxx.xxx.7.0
>> xxx.xxx.12.0
>> xxx.xxx.13.0
>> xxx.xxx.14.0
>> xxx.xxx.15.0
>>
>> please guide me or else suggest if this is already disscussed.
>>
>> Thanks
>> Asshy
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>>
>>
>>
>>
>>
>>
>>
>>
>
>
> --
> Fahad Khan
Blogs and organic groups at http://www.ccie.net
This archive was generated by hypermail 2.1.4 : Mon Sep 01 2008 - 08:15:33 ART