Re: OSPF NBMA and Multipoint Beighbourship Issues

I was being lazy too :-) and just googled for something well-written on
this matter instead of doing all the hard work myself.

This URL might help you in your endeavors.
http://ardenpackeer.com/routing-protocols/tutorial-ospf-network-types-and-frame-relay-part-4/

HTH,
A.

Con Spathas wrote:
> I was being lazy - I simply copied that debug from a post I made on
> another forum a few weeks ago with a similar issue! ;)
>
> I tried it again now though just quickly and the thing I noticed
> between the P2P router and the B/Cast router is that B/Cast was going
> through the DR/BDR election process, whereas P2P wasn't - nothing
> jumped out and said mis-matched interface types or anything like that.
>
> I'm now going back to being lazy and reading Doyle instead of working on labs.
>
> On Mon, Jul 13, 2009 at 8:57 PM, <Keegan.Holley_at_sungard.com> wrote:
>
>> Try debug ip ospf adj and events. Sorry not being lazy, just still working.
>> I'll probably try this on my own later.
>>
>>
>>
>> From: Con Spathas <ccie19226_at_googlemail.com>
>> To:
>> Divin Mathew John <divinjohn_at_gmail.com>
>> Cc: Keegan.Holley_at_sungard.com, Cisco certification <ccielab_at_groupstudy.com>,
>> nobody_at_groupstudy.com
>> Date: 07/13/2009 03:54 PM
>> Subject: Re: OSPF NBMA and Multipoint Beighbourship Issues
>> Sent by: nobody_at_groupstudy.com
>> ________________________________
>>
>>
>> I caught this on the 'debug ip ospf spf'
>>
>> Mismatched network types sees this:
>>
>> *Mar 1 00:05:56.115: Processing link 1, id 2.2.2.2, link data
>> 12.12.12.1, type 1
>> *Mar 1 00:05:56.115: No RTR Back link
>>
>> Matches networks types (in this cast both p2p) see this:
>>
>> *Mar 1 00:13:12.087: Processing link 2, id 2.2.2.2, link data
>> 255.255.255.255, type 3
>> *Mar 1 00:13:12.091: Add better path to LSA ID 2.2.2.2, gateway
>> 2.2.2.2, dist 11
>> *Mar 1 00:13:12.095: Add path: next-hop 12.12.12.2, interface
>> Ethernet0/0
>>
>> I can't seem to find much about the 'No RTR Back link' debug though.
>>
>> On Mon, Jul 13, 2009 at 7:46 PM, Divin Mathew John<divinjohn_at_gmail.com>
>> wrote:
>>
>>> I think i figured it out... as long as the timers are same... they
>>> neighbourship comes up... but...if the Network types arent fully
>>> compatible
>>> with each other prefixes arent exchanged.!
>>> Thanking You
>>>
>>> Yours Sincerely
>>>
>>> Divin Mathew John
>>> divinjohn_at_gmail.com
>>> divin_at_dide3d.com
>>> http://www.dide3d.com
>>> +91 9945430983
>>> +91 9846697191
>>> +974 5008916
>>> PGP PUBLIC KEY BLOCK @ http://www.dide3d.com/divin_Public_PGP_key.txt
>>>
>>>
>>> On Mon, Jul 13, 2009 at 11:39 PM, <Keegan.Holley_at_sungard.com> wrote:
>>>
>>>
>>>> Point to mutipoint interfaces don't elect DR's. All the DR really does
>>>> is
>>>> ensure that there is only one lsdb per subnet which is done here. Just
>>>> because the other router thinks there is no DR doesn't change the fact
>>>> the
>>>> R1 has the full DB. I tried this in a lab once. I can't remember why
>>>> the
>>>> routes disappear though. Do some debugs if you really want to know
>>>> what's
>>>> going on. Since they are fully adjacent my guess is that they both have
>>>> the
>>>> LSDB but there is something wrong with the LSA's themselves like invalid
>>>> next hops or sth. But that's just a guess of course. I'm sure someone
>>>> will
>>>> correct me shortly.
>>>>
>>>> Keegan
>>>>
>>>>
>>>>
>>>>
>>>> From: Divin Mathew John <divinjohn_at_gmail.com> To: Cisco certification <
>>>> ccielab_at_groupstudy.com> Date: 07/13/2009 01:33 PM Subject: OSPF NBMA and
>>>> Multipoint Beighbourship Issues Sent by: nobody_at_groupstudy.com
>>>> ------------------------------
>>>>
>>>>
>>>>
>>>> hello
>>>>
>>>> I have this scenario.... R1------FR-Switch----R2
>>>>
>>>> R1 to R2 102 Dlci
>>>> R2 to R1 DLCI 201
>>>>
>>>> R1 config
>>>>
>>>> interface Serial0/0
>>>> ip address 12.1.1.1 255.255.255.0
>>>> encapsulation frame-relay
>>>> ip ospf network point-to-multipoint
>>>> serial restart-delay 0
>>>> frame-relay map ip 12.1.1.2 102 broadcast
>>>> !
>>>> router ospf 1
>>>> log-adjacency-changes
>>>> network 1.1.1.1 0.0.0.0 area 0
>>>> network 12.1.1.1 0.0.0.0 area 0
>>>> neighbor 12.1.1.2
>>>>
>>>> R2 Config
>>>>
>>>> interface Loopback0
>>>> ip address 2.2.2.2 255.255.255.0
>>>> !
>>>> interface Serial0/0
>>>> ip address 12.1.1.2 255.255.255.0
>>>> encapsulation frame-relay
>>>> ip ospf network non-broadcast
>>>> serial restart-delay 0
>>>> frame-relay map ip 12.1.1.1 201 broadcast
>>>> !
>>>> interface Serial0/1
>>>> no ip address
>>>> shutdown
>>>> serial restart-delay 0
>>>> !
>>>> interface Serial0/2
>>>> no ip address
>>>> shutdown
>>>> serial restart-delay 0
>>>> !
>>>> interface Serial0/3
>>>> no ip address
>>>> shutdown
>>>> serial restart-delay 0
>>>> !
>>>> router ospf 1
>>>> log-adjacency-changes
>>>> network 2.2.2.2 0.0.0.0 area 0
>>>> network 12.1.1.2 0.0.0.0 area 0
>>>> !
>>>>
>>>> R1#show ip ospf neighbor
>>>>
>>>> Neighbor ID Pri State Dead Time Address
>>>> Interface
>>>> 12.1.1.2 0 FULL/ - 00:01:32 12.1.1.2
>>>> Serial0/0
>>>>
>>>> R1#sio int se0/0
>>>> Serial0/0 is up, line protocol is up
>>>> Internet Address 12.1.1.1/24, Area 0
>>>> Process ID 1, Router ID 12.1.1.1, Network Type POINT_TO_MULTIPOINT,
>>>> Cost:
>>>> 64
>>>> Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT,
>>>> Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
>>>> oob-resync timeout 120
>>>> Hello due in 00:00:11
>>>> Supports Link-local Signaling (LLS)
>>>> Index 1/1, flood queue length 0
>>>> Next 0x0(0)/0x0(0)
>>>> Last flood scan length is 1, maximum is 1
>>>> Last flood scan time is 4 msec, maximum is 4 msec
>>>> Neighbor Count is 1, Adjacent neighbor count is 1
>>>> Adjacent with neighbor 12.1.1.2
>>>> Suppress hello for 0 neighbor(s)
>>>>
>>>> R2#show ip ospf neighbor
>>>> 12.1.1.1 1 FULL/BDR 00:01:33 12.1.1.1
>>>> Serial0/0
>>>>
>>>> R2#sio int se0/0
>>>> Serial0/0 is up, line protocol is up
>>>> Internet Address 12.1.1.2/24, Area 0
>>>> Process ID 1, Router ID 12.1.1.2, Network Type NON_BROADCAST, Cost: 64
>>>> Transmit Delay is 1 sec, State DR, Priority 1
>>>> Designated Router (ID) 12.1.1.2, Interface address 12.1.1.2
>>>> Backup Designated router (ID) 12.1.1.1, Interface address 12.1.1.1
>>>> Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
>>>> oob-resync timeout 120
>>>> Hello due in 00:00:06
>>>> Supports Link-local Signaling (LLS)
>>>> Index 1/1, flood queue length 0
>>>> Next 0x0(0)/0x0(0)
>>>> Last flood scan length is 1, maximum is 1
>>>> Last flood scan time is 0 msec, maximum is 4 msec
>>>> Neighbor Count is 1, Adjacent neighbor count is 1
>>>> Adjacent with neighbor 12.1.1.1 (Backup Designated Router)
>>>> Suppress hello for 0 neighbor(s)
>>>>
>>>> Now the adjacency forms between R1 and R2 ...but routes aren't being
>>>> exchanged.. but adj stays up always..! According to what i have read, If
>>>> a
>>>> network type wants DR/BDR election..it will only make neighbor with a
>>>> network type with DR/BDR election.. like NBMA and Broadcast are
>>>> compatible.
>>>> P-2-M and P2P are compatible... when timers are adjusted of course. But
>>>> my
>>>> question why is NBMA forming neighbourship with P2M!?
>>>>
>>>>
>>>> Blogs and organic groups at http://www.ccie.net
>>>>
>>>> _______________________________________________________________________
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>>>>
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>
>
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>
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Received on Wed Jul 15 2009 - 11:35:53 ART