Re: OSPF LSA type 3 filtering

I would take that a step further.

If the Type 2 only describes the topology, then how does the router know what
the mask of the ethernet link is?
The only place I see it is in the Type 2 LSA.

In fact, the Router LSA does not even increment the link count when the
ethernet link is flapped and brought back up.

Paul Negron
CCIE# 14856
negron.paul_at_gmail.com
303-725-8162

On Jan 2, 2013, at 8:54 PM, Narbik Kocharians <narbikk_at_gmail.com> wrote:

> 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.comSr.
Technical Instructor YES! We take Cisco Learning Credits!
>>> A Cisco Learning Partner
>>>
>>>
>>>
>>>
>>> --
>>> Narbik Kocharians
>>> CCSI#30832, CCIE# 12410 (R&S, SP, Security) www.MicronicsTraining.comSr.
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
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Wed Jan 02 2013 - 23:34:24 ART