Re: OSPF intra area filtering

From: Narbik Kocharians (narbikk@gmail.com)
Date: Wed Jan 07 2009 - 04:18:33 ARST

You can use the "IP Ospf database-filter all out" command on the ABR (That's
if i understand the question correctly), by the way could you be a little
more specific about your question?

By the way the routers within the same area can have different database and
OSPF will be fine, just use the above command.

On Tue, Jan 6, 2009 at 5:16 PM, Pavel Bykov <slidersv@gmail.com> wrote:

> Right... now I haven't finished reading before replying. sorry. I *assumed*
> he didn't want to use that command on any of the routers, not just specific
> to A0.
>
> Sergei? How about it?
>
>
> On Wed, Jan 7, 2009 at 1:54 AM, Piotr <usaccie@gmail.com> wrote:
>
> > "R1
> > int lo0
> >
> > ip address 1.1.1.1 255.255.255.0
> >
> > access-list 1 deny 1.1.1.0
> > access-list per any
> >
> > route-map REDIST_LO0 per 10
> > match inter lo0
> >
> > router ospf 1
> > redistribute connected subnets route-map REDIST_LO0
> > distribute-list 1 out
> >
> > "
> >
> > I don't understand why that would not work.
> >
> > The way I read it is that he does not want to advertise 1.1.1.x to any
> > other routers. He does not want to to filter on the ABR and also he does
> not
> > want to filter on any of the 20 routers in area 0.
> >
> > This should work because it's an ASBR (redistribute connected) and in
> this
> > situation OSPF will accept "distribute-list* out*" because it's an ASBR.
> > It's a type 5 LSA and will be filtered from R1's OSPF database on R1. So
> > none of the other routers will see the route in their routing table or
> > database.
> >
> >
> >
> > On Tue, Jan 6, 2009 at 6:31 PM, Pavel Bykov <slidersv@gmail.com> wrote:
> >
> >> Piotr, that he does not wants to do (he needs to do it on more routers).
> >> I have also misread the post the first time.
> >>
> >> Ok, Sergei, here are the options in my opinion:
> >>
> >> 1. Redistribute connected, effectively making router an ASBR. Then use
> >> "summary-address not-advertise" option
> >> i.e.*
> >> router ospf 1
> >> redistribute connected subnets
> >> summary-address 1.1.1.0 255.255.255.0 not-advertise
> >> *
> >>
> >> 2. Redistribute connected using E1 metric, set the metric to nearly
> >> maximum value. i.e.
> >> (out of my head, not for copy-pasting of course)
> >>
> >> route-map TRICK
> >> match interface lo0
> >> set type E1
> >> set metric to about maximum -5
> >>
> >> router ospf 1
> >> redistribute connected subnets
> >>
> >>
> >>
> >>
> >> On Wed, Jan 7, 2009 at 12:21 AM, Piotr <usaccie@gmail.com> wrote:
> >>
> >>> My bad. I misread your email.
> >>>
> >>> You an redistribute the loopback on R1.
> >>> Then use a distribute-list out.
> >>>
> >>> int lo0
> >>> ip address 1.1.1.1 255.255.255.0
> >>>
> >>> access-list 1 deny 1.1.1.0
> >>> access-list per any
> >>>
> >>> route-map REDIST_LO0 per 10
> >>> match inter lo0
> >>>
> >>> router ospf 1
> >>> redistribute connected subnets route-map REDIST_LO0
> >>> distribute-list 1 out
> >>>
> >>>
> >>> On Tue, Jan 6, 2009 at 6:16 PM, Piotr <usaccie@gmail.com> wrote:
> >>>
> >>> > Try this
> >>> >
> >>> > On R2
> >>> >
> >>> > ip prefix-list FILTERLSA3 seq 5 deny 111.111.111.0/24
> >>> > ip prefix-list FILTERLSA3 seq 10 permit 0.0.0.0/0 le 32
> >>> > router ospf 1
> >>> > area 1 range filter-list FILTERLSA3 in
> >>> >
> >>> >
> >>> > On Tue, Jan 6, 2009 at 7:34 AM, Sergei Udovenko <udovenko@gmail.com
> >>> >wrote:
> >>> >
> >>> >> Hello to all CCIE candidates!
> >>> >> I've the following topology:
> >>> >>
> >>> >> lo:1.1.1.x->R1---R2----R3
> >>> >>
> >>> >> R1 - area 1
> >>> >> R2 - ABR
> >>> >> R3 - area 0
> >>> >>
> >>> >> The issue that I want that 1.1.1.x will not be advertised to the
> >>> R2(ABR)
> >>> >> and
> >>> >> all other routers int area 0. So the problem here is that I want to
> >>> find
> >>> >> workaround to filter route in intra- area and not on ABR with area 1
> >>> range
> >>> >> 1.1.1.0 255.255.255.0 not-advertise command. Also because there are
> >>> about
> >>> >> 20
> >>> >> routers in area 0 that shouldn't receive 1.1.1.x and I don't want to
> >>> >> use distribute-list
> >>> >> x in on each router in area 0 to filter the local routing table on
> >>> each
> >>> >> router.
> >>> >>
> >>> >>
> >>> >> May be some of you have any suggestion how to get this workaround?
> >>> >>
> >>> >> --------------------
> >>> >> Best regards,
> >>> >> Sergei
> >>> >>
> >>> >>
> >>> >> Blogs and organic groups at http://www.ccie.net
> >>> >>
> >>> >>
> >>> _______________________________________________________________________
> >>> >> Subscription information may be found at:
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> >>>
> >>>
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> >>>
> >>> _______________________________________________________________________
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> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >> --
> >> Pavel Bykov
> >> ----------------
> >> Don't forget to help stopping the braindumps, use of which reduces value
> >> of your certifications. Sign the petition at
> >> http://www.stopbraindumps.com/
> >>
> >
> >
>
>
> --
> Pavel Bykov
> ----------------
> Don't forget to help stopping the braindumps, use of which reduces value of
> your certifications. Sign the petition at http://www.stopbraindumps.com/
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
>
>
> 

-- 
Narbik Kocharians
CCSI#30832, CCIE# 12410 (R&S, SP, Security)
www.MicronicsTraining.com
www.Net-Workbooks.com
Sr. Technical Instructor

Blogs and organic groups at http://www.ccie.net

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