From: simon hart (simon@harttel.com)
Date: Fri Sep 02 2005 - 16:19:21 GMT-3
Ed,
The prefix lists you have created are incorrect.
Firstly when creating a prefix list and using the ge and le statements the
following rules apply
ge must be greater than length value. The length value is the value at the
end of the prefix i.e. 198.198.0.0/16. Therefore ge must be a value larger
than 16
le must be greater or equal than the ge value. Therefore if you have a
value of 17 for ge, then the value for le must be 17 or greater (up to 32).
With that said, it maybe wise to understand what each means. When using ge
and/or le at the end of the prefix list, then the syntax of the prefix list
changes (from behaviour with no ge or le statements).
Using the following statement as an example
198.198.0.0/16 ge 17 le 24
The first part states that the first 16 bits of the prefix must match, that
is 198.198. the last 16 bits can be anything.
The ge 17 means that the subnet mask for the prefix must be at least 17 bits
or 255.255.128.0
The le 24 means that the subnet mask for the prefix must be at most 24 bits
or 255.255.255.0
Therefore the above statement allows a prefixes that begin with 198.198 and
that have a subnet mask of between 17 and 24 bits.
In order to meet your requirements you are wanting a prefix that starts with
198.198.x.0 that has only a 24 bit mask. This would be achieved with the
following
ip prefix-list fil-eigrp permit 198.198.0.0/16 ge 24 le 24
HTH
Simon
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Ed Tan
Sent: 02 September 2005 19:58
To: ccielab@groupstudy.com
Subject: Ip prefix-list question
Hi group,
The question require us "to ignore all routes except 198.198.z.0/24",
so I try to configure a prefix-list and apply to the distribute-list
router(config)#ip prefix-list filter-eigrp permit 198.198.0.0/16 ge 16 le 24
% Invalid prefix range for 198.198.0.0/16, make sure: len < ge-value <=
le-value
Why I receive this error message? and I also try below which I got the
same error message?
router(config)#ip prefix-list fil-eigrp permit 198.198.0.0/16 ge 17 le 14
router(config)#ip prefix-list fil-eigrp permit 198.198.0.0/16 ge 24 le 14
I hope anyone can provide a solution for the above requirement.
Thanks,
Ed
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