Re: How to filter external OSPF routes from database ?

Stubby area :-)

External LSAs (LSA5) can be filtered on ASBRs using summary-address
NET MASK not-advertise. I don't know about any other way of filtering
them on ABRs except using stubby areas.

Regards,
Miroslav

On Nov 10, 2009, at 10:15 PM, Martin Hogan wrote:

> What does the Cisco Doc tell you about that command?
>
> Hint: It's only effective on a particular LSA type.
>
>
>
> On Tue, Nov 10, 2009 at 7:44 AM, Tomasz Solski
> <tom.solski_at_gmail.com> wrote:
>
>> How to filter external OSPF routes from database ?
>>
>> Here is an example:
>>
>> R1------Ar0------R2------Ar1-------R3
>>
>> R1 redistributes routes into Area 0.
>>
>> I want ot configure R2 so R3 does not have a specific external
>> route in its
>> database.
>>
>> I tried on R2:
>> <<<
>> ip prefix-list R1toR3 seq 5 deny 1.1.12.0/24
>> ip prefix-list R1toR3 seq 10 permit 0.0.0.0/0 le 32
>> router ospf 1
>> area 1 filter-list prefix R1toR3 in
>>>>>
>>
>> but it looks like external routes can not be filtered with filter
>> list. As
>> soon as I advertise 1.1.12.0/24 on R1, instead of redistributing
>> it, it
>> disappears from R3's database and routing table.
>>
>>
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Received on Tue Nov 10 2009 - 22:21:54 ART