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Re: Prefix-list posted 10/02/2007
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Hi Subodh,

I have not labbed it to verify.

Nevertheless, if my understanding is correct, for "0.0.0.0/0 le 32", the
prefix length is as follows:

0 <= len <= 32

For "0.0.0.0/0 ge 1", prefix length is:

1 <= len <= 32

The prefix length of default route is 0. Thus IMHO, the "0.0.0.0/0 ge 1"
will not match the default route. It will be denied by the next implicit
deny statement. Do correct me if I'm wrong.


Thank you.

B.Rgds,
Lim TS




On 10/2/07, subodh.rawat@xxxxxxxxx <subodh.rawat@xxxxxxxxx> wrote:
>
> prefix-list 0.0.0.0/0 le 32 and 0.0.0.0/0 ge 1 have same effect, i.e. To
> permit or deny any routes. While 0.0.0.0/0 is exact match of default
> route.
>
> So below two configurations have same effect.
>
> Ip prefix-list MYLIST deny 192.168.1.0/24
>
> Ip prefix-list MYLIST permit 0.0.0.0/0 ge 1
> AND
> Ip prefix-list MYLIST deny 192.168.1.0/24 <http://192.168.1.0/24>
> Ip prefix-list MYLIST permit 0.0.0.0/0 <http://0.0.0.0/0>  le 32
>
> Hope this helps.
>
> Regards
> Subodh
>
> ________________________________
>
> From: Saul Arjona [mailto:saul.arjona.bueno@xxxxxxxxx]
> Sent: Tuesday, October 02, 2007 11:36 AM
> To: Subodh Singh Rawat (WT01 - TELECOM SERVICE PROVIDER)
> Cc: sameh@xxxxxxxxxxxxxx; ccielab@xxxxxxxxxxxxxx
> Subject: Re: Prefix-list
>
>
> If you use:
>
> Ip prefix-list MYLIST deny 192.168.1.0/24
>
> Ip prefix-list MYLIST permit 0.0.0.0/0 ge 1
>
> You would be denying 192.168.1.0/24 network and also de default route
> 0.0.0.0 and permitting everything else
>
> Since the task states that you deny 192.168.1.0/24 and permit everything
> else I would use
>
> Ip prefix-list MYLIST deny 192.168.1.0/24
> Ip prefix-list MYLIST permit 0.0.0.0/0 le 32
>
> regards
> -Saul
>
>
>
>
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