From: elping (elpingu@xxxxxxxxxx)
Date: Fri Jun 14 2002 - 02:16:08 GMT-3
thanks all for confirming my thoughts........apreciate the help
el ping
Brian McGahan wrote:
> Ip prefix-list 2 seq 5 deny 200.200.0.0/24 is an exact match for that
> prefix. If you use the GE and LE values, the LEN value no longer means
> the prefix-length. Instead, it means how many bits you are checking
> sequentially from the left.
>
> Your prefix-list should read:
>
> Ip prefix-list X seq 5 deny 200.200.0.0/16 ge 24 le 24
> Ip prefix-list X seq 10 permit 0.0.0.0/0 le 32 <---- explicit permit any
>
> This means:
>
> 1. Deny prefixes for which
> A) The first 16 bits are 200.200. and
> B) The prefix-length is greater-than or equal to 24, and less-than or
> equal to 24. (hence, 24)
>
> 2. Permit everything else
>
> permit any in prefix-list syntax reads:
>
> ip prefix-list X permit 0.0.0.0/0 le 32
>
> an exact match for a default route, on the other hand, would read:
>
> ip prefix-list X permit 0.0.0.0/0
>
> to match an exact host route:
>
> ip prefix-list X permit 1.2.3.4/32
>
> to match all class A routes:
>
> ip prefix-list X permit 0.0.0.0/1 ge 8 le 8
>
> to match all routes with a first octet of 10, and whose masks are
> greater than or equal to 12, but less than or equal to 20:
>
> ip prefix-list X permit 10.0.0.0/8 ge 12 le 20
>
> HTH
>
> Brian McGahan, CCIE #8593
> Director of Design and Implementation
> brian@cyscoexpert.com
>
> CyscoExpert Corporation
> Internetwork Consulting & Training
> http://www.cyscoexpert.com
> Voice: 847.674.3392
> Fax: 847.674.2625
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> elping
> Sent: Thursday, June 13, 2002 10:54 PM
> To: ccielab@groupstudy.com
> Subject: prefix-list
>
> i have been configuring prefix-list and am i having a hard time....
> i am trying to block all /24 in network 200.200.x.x
>
> ip prefix-list 2 seq 5 deny 200.200.0.0/24
> it does not work
>
> i have tryed
> ip prefix-list 2 seq 5 permit 200.0.0.0/24
> stilll does not work
>
> what i am doing wrong ....?
> can someone xplain prefix-list
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