Re: OSPF LSA type 3 filtering

Both of these commands will affect the ospf database, and neither will
affect the local routing table of the ABR that uses them.

*area range - with not-advertise will prevent LSA type 3 generation to ALL
areas. Affects OSPF Intra area, and inter-area learned routes only.

*area filter-list - Is very similar to area range with not-advertise, in
the way it affects the actual OSPF database, but allows you to be a bit
more granular. For example: You have an ABR connected to AREA 0, 10, 20,
and 30. You want to stop some routes from AREA 10, going to AREA 20. "area
20 filter-list prefix foo-routes in". Affects OSPF Intra area, and
inter-area learned routes only.

-Yuri

On Tue, Jan 1, 2013 at 10:41 PM, ccie99999 <ccie99999_at_gmail.com> wrote:

> Sara, as far as I know it works in this way:
>
> with the first option, the filter-list you can filter only lsa type 3 and
> this filtering only affects the local routing table, not the OSPF database.
>
> with the second option you are filtering every LSA type but this filtering
> affect the OSPF database, therefore also the local routing table.
>
> There is another option that applies to route summarization when
> distributing routes into OSPF. This also has the feature "not-advertise",
> and the syntax is: summary-address ip-prefix summary-mask [not-advertise]
>
> I hope someone else can add more details.
>
>
>
>
>
>
>
>
>
> On Wed, Jan 2, 2013 at 5:16 AM, Sarad <tosara_at_gmail.com> wrote:
>
> > Hi Experts,
> >
> > Can somebody help me to get my head around this, I've been labbing ospf
> > type 3 filtering, Main method use for this is filter-list command. Which
> we
> > can use to filter route based on the direction (in /out)
> >
> >
> >
> > Then there is area range command with not-advertise switch we can use to
> do
> > limited filtering on ABR. When I tested this it only works when I filter
> > LSA type 3 from non backbone area to a backbone area.
> >
> > Can somebody help me to explain what is the exact usage of this command
> in
> > term of filtering in OSPF. There is nothing much in the doc CD
> >
> > *
> > *
> > *area area-id filter-list prefix prefix-list-name {in | out}
> > area* area-id *range* ipv6-prefix /prefix-length [*advertise* | *
> > not-advertise*] [*cost* cost]
> >
> >
> > Cheers
> > Sara
> >
> >
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>
>
> --
> @ccie99999
>
>
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Received on Wed Jan 02 2013 - 11:32:53 ART