Re: OSPF LSA type 3 filtering

I am NOT disagreeing with what you wrote. You are going deep into
semantics, and I am not going that route at all.

We were talking about the differences between the *Area range* and *Area
Filter-list* command, and I think I showed it in the IOS so there wont be
any misunderstanding, and if you configure these commands on any IOS, the
result will be the same. The gentlemen (Sarad and Tim) were happy with what
they saw, and I am even happier that I could show them something that they
wanted to see.

You see this is the difference between two ways of explaining something to
a student, I like the simple route, in a simple topology, using simple IP
addressing, using simple words and to be honest, I have found that to be
very effective. You have your own way, and you had one student (Joe, he
travelled all over the world, he was so happy) very excited, and I am sure
that youve had lots of success doing it your way.

To the best of my knowledge, LSA type-2s provide information about the
subnet mask on that segment, if you have a serial P2P connection, you wont
have LSA Type-2s, because the link itself is advertised as stub and Transit
(if ENET), which includes the network number and the subnet mask
immediately below it. This does not happen when we have a Multiaccess
network such as Ethernet, therefore, the LSA Type-2s are needed for
reachability information. Now..am I correct semantically? I dont know.

But am I correct technically (Proof by IOS) I think so. I guess Petr
Lapukhov explained it once as a glue LSA, and I do agree with that.

May be sometimes we use the terms loosely, so the students can make sense,
and this is why I like to do the IOS thing, because the behavior that I see
is the behavior that I trust and its the behavior that I teach.

The DRs generate LSA Type-2s and it describes all the routers attached to
the network, which is flooded in the area that contains the network just
like a router LSA. Remember that LSA Type-2s have two important fields:

Network Mask  This indicates the network mask for the transit link.

Attached Router  Which includes the RID of all routers associated with
this transit link.

NOW.does it provide reachability? I dont see the Ethernet link advertised
or I should say referenced in any LSAs, do you? The only LSA that
advertises/floods the actual Mask is LSA Type-2. Type-3 LSAs provide
summary information about Type-1 and 2 LSAs for other areas.

On Wed, Jan 2, 2013 at 8:26 PM, Brian McGahan <bmcgahan_at_ine.com> wrote:

> What exactly are you disagreeing with that I said? If you want to have a
> reasonable technical discussion Im more than open to it; Im not trying to
> start an argument with you.****
>
> ** **
>
> You said that area range filters LSA 2. This is not the case. Its not
> even the case that it filters LSA 1. Programmatically the area range
> feature is not invoked until after the ABR internally generates LSA 3. LSA
> 3 is the summarization of the Intra-Area topology information, but not the
> prefix/reachability information. area range can then be used to
> summarize the reachability information of multiple LSA 3s that would
> normally have been advertised.****
>
> ** **
>
> To say that area range summary-address or area filter-list
> summarizes LSA 2 (or 1) perpetuates the misconception that there is no
> difference between topology information and reachability information in
> OSPF, where in reality the separation of these two is the reason that OSPF
> is such a highly scalable protocol.****
>
> ** **
>
> Brian McGahan, CCIE #8593 (R&S/SP/Security)****
>
> bmcgahan_at_INE.com****
>
> ** **
>
> Internetwork Expert, Inc.****
>
> http://www.INE.com****
>
> ** **
>
> *From:* Narbik Kocharians [mailto:narbikk_at_gmail.com]
> *Sent:* Wednesday, January 02, 2013 9:54 PM
> *To:* Joseph L. Brunner
> *Cc:* Brian McGahan; Cisco certification
>
> *Subject:* Re: OSPF LSA type 3 filtering****
>
> ** **
>
> I meant to say No theory, show it in IOS.****
>
> On Wed, Jan 2, 2013 at 7:53 PM, Narbik Kocharians <narbikk_at_gmail.com>
> wrote:****
>
> Can you show me what LSA conveys the Ethernet link between R1 and R2? In
> my example. Once again no theory IOS.****
>
> ** **
>
> On Wed, Jan 2, 2013 at 7:48 PM, Joseph L. Brunner <joe_at_affirmedsystems.com>
> wrote:****
>
> Clap Clap Clap Clap ((|))((|))
> =X=
> UUU UUU
>
> MEOWTH!!!
>
> That was the best post in 6 years here....
>
> So that is what I read the 34,332 posts about workbooks, 9,810 posts about
> Pakistan schools and 5,641 posts about lab questions to learn...
>
> Carry on gents!****
>
>
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> Brian McGahan
> Sent: Wednesday, January 02, 2013 10:28 PM
> To: Narbik Kocharians
> Cc: Cisco certification****
>
> Subject: RE: OSPF LSA type 3 filtering
>
> Sure. Reachability information means the actual prefixes being
> advertised, like 10.0.0.0/8, 1.2.3.4/32, etc. Topology information means
> the graph of connectivity within the area that affects the SPF calculation.
> SPF runs to find the shortest path between nodes, not between prefixes.
> This is why in OSPFv3 the definition of topology information and
> reachability information was further separated into Link LSAs and
> Intra-area Prefix LSAs.
>
> In OSPFv2 you can see this from the output of the database:
>
> Rack1SW3#show ip ospf database
>
> OSPF Router with ID (150.1.9.9) (Process ID 1)
>
> Router Link States (Area 2)
>
> Link ID ADV Router Age Seq# Checksum Link count
> 150.1.3.3 150.1.3.3 660 0x80000051 0x0061BB 1
> 150.1.6.6 150.1.6.6 1019 0x80000050 0x00D8F7 1
> 150.1.7.7 150.1.7.7 894 0x80000055 0x0005C0 5
> 150.1.9.9 150.1.9.9 670 0x8000004F 0x00B13F 2
>
> Net Link States (Area 2)
>
> Link ID ADV Router Age Seq# Checksum
> 155.1.37.3 150.1.3.3 660 0x8000004E 0x0082C4
> 155.1.67.6 150.1.6.6 1019 0x8000004E 0x002BEE
> 155.1.79.9 150.1.9.9 671 0x8000004E 0x009A64
>
>
> The Type 1 Router LSAs contain the information about the links, such as
> their addresses and costs, along with adjacencies. Type 2 LSAs just
> contain the information to simplify the SPF calculation on broadcast and
> non-broadcast networks by making the adjacency look like hub and spoke as
> opposed to full mesh. This way you calculate your SPF cost to the DR and
> it implicitly means you've calculated the SPF cost to all the DR's attached
> neighbor's on the segment. This is why the "Router Link States" above show
> the "Link count" but the "Net Link States" don't, because Type 2 LSA
> doesn't represent the reachability information, it represents the topology.
>
> Topology information is summarized in OSPF by defining areas. A router in
> Area 0 does not run SPF end-to-end to reach a router in Area 1. This is by
> design and by default. By defining areas you don't need to know the entire
> graph of the topology end-to-end. Reachability information however is not
> summarized by default in OSPF, and is what the "area range" or
> "summary-address" commands do. Hence LSA 2 doesn't have anything to do with
> "area range" "summary-address" or "area filter" because topology
> information is summarized regardless as soon as you define areas.
>
>
>
> Brian McGahan, CCIE #8593 (R&S/SP/Security) bmcgahan_at_INE.com
>
> Internetwork Expert, Inc.
> http://www.INE.com
>
> From: Narbik Kocharians [mailto:narbikk_at_gmail.com]
> Sent: Wednesday, January 02, 2013 9:01 PM
> To: Brian McGahan
> Cc: Cisco certification
> Subject: Re: OSPF LSA type 3 filtering
>
> I don't understand where you are going with this, can you show me on IOS
> what you are talking about so we can eliminate any misunderstanding, NOT
> theory, on IOS. But if you don't like the LSA type-2 addition to what we
> were talking about, just remove it.
>
> On Wed, Jan 2, 2013 at 6:55 PM, Brian McGahan <bmcgahan_at_ine.com> wrote:
> Do you mean summarizing topology information or reachability information?
> Topology information is already automatically summarized at the ABR, and
> Type 2 LSA doesn't contain any reachability information, so I'm not sure
> what you're referring to.
>
> Brian McGahan, CCIE #8593 (R&S/SP/Security) bmcgahan_at_INE.com
>
> Internetwork Expert, Inc.
> http://www.INE.com
>
> From: Narbik Kocharians [mailto:narbikk_at_gmail.com]
> Sent: Wednesday, January 02, 2013 8:51 PM
> To: Brian McGahan
> Cc: Cisco certification
>
> Subject: Re: OSPF LSA type 3 filtering
>
> What if in area 1 there are some LSA type-1 and type-2? Can you not filter
> them or summarize them with the "area range" command?
> On Wed, Jan 2, 2013 at 6:17 PM, Brian McGahan <bmcgahan_at_ine.com> wrote:
> How does it affect Type 2 LSAs?
>
>
> Brian McGahan, CCIE #8593 (R&S/SP/Security) bmcgahan_at_INE.com
>
> Internetwork Expert, Inc.
> http://www.INE.com
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> Narbik Kocharians
> Sent: Wednesday, January 02, 2013 4:52 PM
> To: Tim Cribbs Jr.
> Cc: Sarad; Cisco certification
> Subject: Re: OSPF LSA type 3 filtering
>
> Thanks very much, I am glad it helped. And yes it also handles LSA type-2.
>
> On Wed, Jan 2, 2013 at 2:28 PM, Tim Cribbs Jr. <tmcribbs_at_gmail.com> wrote:
>
> > I was JUST at this exact point in my studies and was about to comment,
> > but THANKFULLY Narbik got to it before me. lol
> >
> > BTW, area range will also work with type 2 (1&2).
> >
> > Tim
> >
> > On Wed, Jan 2, 2013 at 5:05 PM, Sarad <tosara_at_gmail.com> wrote:
> > > Hi Narbik,
> > >
> > > Thanks for the in detailed expert level explanation. People like you
> > > keep this forum alive. I just did a lab on this and now it make more
> > > sense. So take out from this would be both these commands do the LSA
> > > filtering on
> > ABR
> > > but Area range command would work only when filtering LSA type 1
> > > regenerating as type 3.
> > >
> > >
> > > Area-range
> > >
> > > LSA1 ---> LSA3
> > >
> > > Filter-list
> > >
> > > LSA1/LSA3 -----> LSA
> > >
> > >
> > > Thanks again for the awesome explanation.
> > >
> > > Cheers
> > > Sara
> > >
> > >
> > > On Thu, Jan 3, 2013 at 7:49 AM, Narbik Kocharians
> > > <narbikk_at_gmail.com>
> > wrote:
> > >
> > >> *Sarad,*
> > >> *Since we are all engineers, and engineers are "Must See" people,
> > >> walk through the following lab.*
> > >> **
> > >> *Let s assume the following topology:*
> > >>
> > >>
> > >>
> > >> Lo0(1.1.1.1/24)----- *R1*(F0/0)12.1.1.1/24 --------
> > 12.1.1.2/24(F0/0)*R2*
> > >>
> > >>
> > >>
> > >> *R2*(S0/0.23) 23.1.1.2/24----------23.1.1.3/24(S0/0.32) *R3*
> > >>
> > >>
> > >>
> > >> *R3*(F0/0)34.1.1.3/24--------34.1.1.4/24(F0/0)*R4*
> > >>
> > >>
> > >>
> > >> *OSPF Areas configuration:*
> > >>
> > >> R1 s Lo0 is advertised with a mask of 24 in area 1
> > >>
> > >> The link connecting R1 to R2 is in area 1
> > >>
> > >> The link connecting R2 to R3 is in area 0
> > >>
> > >> The link connecting R3 to R4 is in area 2
> > >>
> > >>
> > >>
> > >> *To verify:*
> > >>
> > >> R1#*Show ip route ospf | I O*
> > >>
> > >> O IA 34.1.1.0 [110/66] via 12.1.1.2, 00:04:13, FastEthernet0/0
> > >>
> > >> O IA 23.1.1.0 [110/65] via 12.1.1.2, 00:04:13, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> R2#*Show ip route ospf | I O*
> > >>
> > >> O IA 34.1.1.0 [110/65] via 23.1.1.3, 00:05:05, Serial0/0.23
> > >>
> > >> O 1.1.1.0 [110/2] via 12.1.1.1, 00:04:35, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> R3#*Show ip route ospf | I O*
> > >>
> > >> O IA 1.1.1.0 [110/66] via 23.1.1.2, 00:04:30, Serial0/0.32
> > >>
> > >> O IA 12.1.1.0 [110/65] via 23.1.1.2, 00:05:05, Serial0/0.32
> > >>
> > >>
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> O IA 1.1.1.0 [110/67] via 34.1.1.3, 00:04:30, FastEthernet0/0
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:04:30, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:04:30, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> *Let s test the "area range" command on R3:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3(config)#*router ospf 1*
> > >>
> > >> R3(config-router)#*area 1 range 1.1.1.0 255.255.255.0 not-ad*
> > >>
> > >>
> > >>
> > >> *To verify the configuration:*
> > >>
> > >> **
> > >>
> > >> *On R4*
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> *O IA 1.1.1.0 [110/67] via 34.1.1.3, 00:07:07, FastEthernet0/0*
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:07:07, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:07:07, FastEthernet0/0
> > >>
> > >>
> > >> *NOTE: It did not work, because the Area range command does not
> > >> work on inter-area routes at all; now let s try this command on
> > >> R2:*
> > >> **
> > >>
> > >> *On R2*
> > >>
> > >> R2(config)#*router ospf 1*
> > >>
> > >> R2(config-router)#*area 1 range 1.1.1.0 255.255.255.0 not-ad*
> > >>
> > >>
> > >>
> > >> *To verify the configuration:*
> > >> **
> > >> *On** R2*
> > >>
> > >> *NOTE: It s in the routing table and the database of the local
> > >> router
> > >> (R2):*
> > >>
> > >>
> > >>
> > >> R2#*sh ip route ospf | I O*
> > >>
> > >> O IA 34.1.1.0 [110/65] via 23.1.1.3, 00:00:33, Serial0/0.23
> > >>
> > >> *O 1.1.1.0 [110/2] via 12.1.1.1, 00:00:33, FastEthernet0/0*
> > >>
> > >>
> > >>
> > >> R2#*Show ip ospf da router*
> > >>
> > >>
> > >>
> > >> *Link connected to: a Stub Network*
> > >>
> > >> * (Link ID) Network/subnet number: 1.1.1.0*
> > >>
> > >> * (Link Data) Network Mask: 255.255.255.0*
> > >>
> > >> * Number of TOS metrics: 0*
> > >>
> > >> * TOS 0 Metrics: 1*
> > >>
> > >> * *
> > >>
> > >> *But is it going to be advertised to the other areas? Let s check:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3#*Show ip route ospf | I O*
> > >>
> > >> O IA 12.1.1.0 [110/65] via 23.1.1.2, 00:07:49, Serial0/0.32
> > >>
> > >>
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:18:52, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:09:14, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> *As you can see the answer is "NO". *
> > >>
> > >> *So you can see that it prevented the LSA type-3 generation for the
> > >> 1.1.1.0/24 prefix on the router that sees the route as LSA-1 and
> > LSA-3. *
> > >>
> > >> * *
> > >>
> > >> *NOW .let s test the area filter-list , but before we test it, we
> > should
> > >> remove the Area range command:*
> > >>
> > >> **
> > >>
> > >> *On R2*
> > >>
> > >> R2(config)#*router ospf 1*
> > >>
> > >> R2(config-router)#*No area 1 range 1.1.1.0 255.255.255.0
> > >> not-advertise*
> > >>
> > >>
> > >>
> > >> *To verify the configuration:*
> > >>
> > >> **
> > >>
> > >> *On R3*
> > >>
> > >>
> > >>
> > >> R3#*Show ip route ospf | I O*
> > >>
> > >> *O IA 1.1.1.0 [110/66] via 23.1.1.2, 00:00:16, Serial0/0.32*
> > >>
> > >> O IA 12.1.1.0 [110/65] via 23.1.1.2, 00:12:47, Serial0/0.32
> > >>
> > >>
> > >>
> > >> *Let s configure the area filter-list on R2:*
> > >>
> > >> * *
> > >>
> > >> *On R2*
> > >>
> > >> R2(config)#*IP prefix-list tst deny 1.1.1.0/24*
> > >>
> > >> R2(config)#*IP prefix-list tst permit 0.0.0.0/0 le 32*
> > >>
> > >>
> > >>
> > >> R2(config)#*router ospf 1*
> > >>
> > >> R2(config-router)#*area 1 filter-list prefix tst out*
> > >>
> > >>
> > >>
> > >> *To verify the configuration:*
> > >>
> > >> **
> > >>
> > >> *On R2*
> > >>
> > >>
> > >>
> > >> R2#*Show ip route ospf | I O*
> > >>
> > >> O IA 34.1.1.0 [110/65] via 23.1.1.3, 00:02:12, Serial0/0.23
> > >>
> > >> *O 1.1.1.0 [110/2] via 12.1.1.1, 00:02:12, FastEthernet0/0*
> > >>
> > >>
> > >>
> > >> R2#*Show ip ospf da router*
> > >>
> > >>
> > >>
> > >> *Link connected to: a Stub Network*
> > >>
> > >> * (Link ID) Network/subnet number: 1.1.1.0*
> > >>
> > >> * (Link Data) Network Mask: 255.255.255.0*
> > >>
> > >> * Number of TOS metrics: 0*
> > >>
> > >> * TOS 0 Metrics: 1*
> > >>
> > >>
> > >>
> > >> *The output of the above show command reveals that the area
> > >> filter-list did not do anything to the routing table or the
> > >> database of the router
> > that
> > >> it s configured on. But let s see how it affected the other
> > >> routers:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3#*Show ip route ospf | I O*
> > >>
> > >> O IA 12.1.1.0 [110/65] via 23.1.1.2, 00:15:36, Serial0/0.32
> > >>
> > >>
> > >>
> > >> *GR8, it worked.*
> > >>
> > >> *So this may seem like both area range and the area filter-list
> > >> commands do the same thing, because of the end result, b**ut let s
> > >> configure the "Area Filter-list" on R3. Remember in the earlier
> > >> test the area range command did not work on R3:*
> > >>
> > >> * *
> > >>
> > >> *Let s remove the previous command before testing it on R3:*
> > >>
> > >>
> > >>
> > >> *On R2*
> > >>
> > >> R2(config)#*router ospf 1*
> > >>
> > >> R2(config-router)#*No area 1 filter-list prefix tst out*
> > >>
> > >>
> > >>
> > >> *To verify the configuration:*
> > >>
> > >> **
> > >>
> > >> *On R3*
> > >>
> > >> R3#*Show ip route ospf | I O*
> > >>
> > >> *O IA 1.1.1.0 [110/66] via 23.1.1.2, 00:00:10, Serial0/0.32*
> > >>
> > >> O IA 12.1.1.0 [110/65] via 23.1.1.2, 00:17:47, Serial0/0.32
> > >>
> > >>
> > >>
> > >> *NOW .let s configure the area filter-list on R3:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3(config)#*ip prefix-list tst deny 1.1.1.0/24*
> > >>
> > >> R3(config)#*ip prefix-list tst permit 0.0.0.0/0 le 32*
> > >>
> > >>
> > >>
> > >> R3(config)#*router ospf 1*
> > >>
> > >> R3(config-router)#*area 0 filter-list prefix tst out*
> > >>
> > >>
> > >>
> > >> *Let s verify the routing table of R4*
> > >>
> > >>
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:29:01, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:19:23, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> *So you can see that it did affect the routers in area 2. *
> > >>
> > >> *So the area range command can be used on the ABR that is
> > >> directly connected to the area that originated the route
> > >> (intra-area routes) or another way of saying it (Does NOT generate
> > >> LSA-3 for the other areas), whereas, the Area filter-list command
> > >> affects LSA type-3s and can be configured on any ABR within your
> > >> routing domain.*
> > >>
> > >>
> > >>
> > >> *You could also use the following command to accomplish the same
> > >> result, the following two methods will work on LSA Type-3s going
> > >> from area 0 to another area: *
> > >>
> > >> **
> > >>
> > >> *Let s remove the previous command and verify:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3(config)#*router ospf 1*
> > >>
> > >> R3(config-router)#*No area 0 filter-list prefi tst out*
> > >>
> > >>
> > >>
> > >> *On R4*
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> *O IA 1.1.1.0 [110/67] via 34.1.1.3, 00:00:27, FastEthernet0/0*
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:35:22, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:25:44, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> *Let s configure a static route on R3 and point it to Null0:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3(config)#*IP route 1.1.1.0 255.255.255.0 null0*
> > >>
> > >>
> > >>
> > >> *To verify the configuration:*
> > >>
> > >> **
> > >>
> > >> *On R4*
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:37:00, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:27:22, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> *Or the following: Let s remove the previous command and verify:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3(config)#*no IP route 1.1.1.0 255.255.255.0 null0*
> > >>
> > >>
> > >>
> > >> *On R4*
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> *O IA 1.1.1.0 [110/67] via 34.1.1.3, 00:00:27, FastEthernet0/0*
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:37:54, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:28:16, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> *Contrary to popular belief, the distribute-list in command can
> > >> affect the neighboring router/s:*
> > >>
> > >>
> > >>
> > >> *On R3*
> > >>
> > >> R3(config)#*access-list 1 deny 1.1.1.0 0.0.0.255*
> > >>
> > >> R3(config)#*access-list 1 permit any*
> > >>
> > >>
> > >>
> > >> R3(config)#*router ospf 1*
> > >>
> > >> R3(config-router)#*distribute-list 1 in*
> > >>
> > >>
> > >>
> > >> *On R4*
> > >>
> > >> R4#*Show ip route ospf | I O*
> > >>
> > >> O IA 23.1.1.0 [110/65] via 34.1.1.3, 00:38:55, FastEthernet0/0
> > >>
> > >> O IA 12.1.1.0 [110/66] via 34.1.1.3, 00:29:17, FastEthernet0/0
> > >>
> > >>
> > >>
> > >> *I hope this helped.*
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> On Tue, Jan 1, 2013 at 9:36 PM, Sarad <tosara_at_gmail.com> wrote:
> > >>
> > >>> Hi All,
> > >>>
> > >>> May be it's not clear what I have sent before let me put this
> > >>> straight,
> > >>>
> > >>> Other than direction (In/Out) what are the limitations of area
> > >>> range command over filter-list command in term of OSPF LSA type 3
> filtering?
> > >>>
> > >>> Thanks
> > >>> Saranga
> > >>>
> > >>>
> > >>> On Wed, Jan 2, 2013 at 4:16 PM, 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
> > >>>
> > >>>
> > >>> 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* <http://www.micronicstraining.com/>
> > >> Sr. Technical Instructor
> > >> YES! We take Cisco Learning Credits!
> > >> A Cisco Learning Partner
> > >
> > >
> > > 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* <http://www.micronicstraining.com/>
> Sr. Technical Instructor
> YES! We take Cisco Learning Credits!
> A Cisco Learning Partner
>
>
> 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 Sr.
> Technical Instructor YES! We take Cisco Learning Credits!
> A Cisco Learning Partner
>
>
>
>
> --
> Narbik Kocharians
> CCSI#30832, CCIE# 12410 (R&S, SP, Security) www.MicronicsTraining.com Sr.
> Technical Instructor YES! We take Cisco Learning Credits!
> A Cisco Learning Partner
>
>
> 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* <http://www.micronicstraining.com/>
> Sr. Technical Instructor ****
>
> YES! We take Cisco Learning Credits!
> A Cisco Learning Partner****
>
>
>
> ****
>
> ** **
>
> -- ****
>
> *Narbik Kocharians**
> *CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> *www.MicronicsTraining.com* <http://www.micronicstraining.com/>
> Sr. Technical Instructor ****
>
> YES! We take Cisco Learning Credits!
> A Cisco Learning Partner****
>

--
*Narbik Kocharians
*CCSI#30832, CCIE# 12410 (R&S, SP, Security)
*www.MicronicsTraining.com* <http://www.micronicstraining.com/>
Sr. Technical Instructor
YES! We take Cisco Learning Credits!
A Cisco Learning Partner
Blogs and organic groups at http://www.ccie.net