Re: OSPF NBMA and Multipoint Beighbourship Issues

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!?
>>>
>>>
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>>>
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>>
>>
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Received on Mon Jul 13 2009 - 21:17:49 ART