Re: OSPF Distance Command .!

@Paul
I think you getting confused with the NSSA Type 7 to Type 5 Conversion at
the ABR. in that case if you have more than one ABR then the Type 7 to type
5 conversion is done by the ABR having the highest router-id.
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
Sent from Bangalore, KA, India

On Fri, May 22, 2009 at 7:05 PM, Paul Cosgrove <paul.cosgrove_at_gmail.com>wrote:

> Hi Chris,
>
> Would be interested to see your scenario and ios version. External route
> calculation is quite different to that of intra area routes. I can't think
> how you would see the same thing if you have a similar topology (three
> routers) and are changing the distance of a router in a similar position
> (instead of matching against a third router reach via the p2m subnet). The
> forwarding address should not be set on a p2m, and each router will have /32
> for its neighbors. If I remember correctly (which I might not) you should
> only have a single external LSA in that case, the one learned from the
> router with the highest RID (assuming costs to the ASBR are equal).
>
> If the forwarding address were set you could certainly see something
> similar, as you may have multiple paths to an address which is directly
> connected to either spoke. Without that set I would have thought you would
> only have one path, unless your topology involved more devices. Will have
> to try it out, and then figure out what I've missed..... :-)
>
> Paul.
>
>
>
>
> Chris Breece wrote:
>
>> Hey Paul,
>>
>> The scenario I saw these results was a point-to-multipoint frame
>> network....
>> no DR involved. The router was the hub and the two spokes were advertising
>> an external E1 to the hub. The distance command using the router ID of one
>> of the spokes, changed the AD for the route to both of the spokes.
>>
>> Chris
>>
>>
>>
>>
>> On Fri, May 22, 2009 at 2:04 AM, Paul Cosgrove <paul.cosgrove_at_gmail.com
>> >wrote:
>>
>>
>>
>>> This does not sound like a bug, just that your R1-R2 link is an OSPF
>>> network type which has a DR elected. The DR acts as a pseudonode which
>>> has
>>> 0 cost connections to each of the routers on that subnet; so it is a
>>> virtual
>>> router located between R1 and R2. It is the DR pseudonode which is
>>> advertising the link. When you apply your distance command it only has
>>> an
>>> effect if the router you match is advertising the subnet, i.e. if it is
>>> the
>>> DR. You have two equal cost paths to the pseudonode, so if your distance
>>> command matches the pseudonode, the AD of both will be changed.
>>>
>>> Hope this helps,
>>>
>>> Paul.
>>>
>>>
>>> Divin Mathew John wrote:
>>>
>>>
>>>
>>>> This is wht i got in the end of the day.
>>>>
>>>> R1-----R0------R2 and there is a connection between R1 and R2. So R0
>>>> has
>>>> 2
>>>> paths to that segment between R1 and R2.
>>>> R1
>>>> interface Loopback0
>>>> ip address 100.100.0.100 255.255.255.0
>>>> !
>>>> interface Loopback1
>>>> ip address 100.100.1.100 255.255.255.0
>>>> !
>>>> interface Loopback2
>>>> ip address 100.100.2.100 255.255.255.0
>>>> !
>>>> interface Loopback3
>>>> ip address 100.100.3.100 255.255.255.0
>>>> !
>>>> interface Serial0/0
>>>> ip address 10.1.1.1 255.255.255.252
>>>> serial restart-delay 0
>>>> !
>>>> interface Serial0/1
>>>> ip address 20.1.1.1 255.255.255.252
>>>> 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
>>>> router-id 100.100.100.100
>>>> log-adjacency-changes
>>>> network 10.1.1.1 0.0.0.0 area 0
>>>> network 20.1.1.1 0.0.0.0 area 0
>>>> network 100.100.0.100 0.0.0.0 area 0
>>>> network 100.100.1.100 0.0.0.0 area 0
>>>> network 100.100.2.100 0.0.0.0 area 0
>>>> network 100.100.3.100 0.0.0.0 area 0
>>>> distance 90 22.22.22.22 0.0.0.0 SELECT_12.1.1.0_from_R1
>>>> !
>>>> ip http server
>>>> ip forward-protocol nd
>>>> !
>>>> !
>>>> !
>>>> !
>>>> ip access-list standard ONLY_R1_LOOPBACKS
>>>> permit 1.1.0.0
>>>> ip access-list standard SELECT_12.1.1.0_from_R1
>>>> permit 12.1.1.0
>>>> ip access-list standard SELECT_12.1.exit
>>>> !
>>>> !
>>>> All router-id Hardcoded. all processes cleared. clear ip route * done.
>>>>
>>>>
>>>> R0's Routing Table
>>>> when R2's ROUTER-ID is lower than R1, A.D of the both the paths gets
>>>> changed
>>>> to the one configured on the Distance command.
>>>> R0#sir
>>>> Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
>>>> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
>>>> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
>>>> E1 - OSPF external type 1, E2 - OSPF external type 2
>>>> i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>>> level-2
>>>> ia - IS-IS inter area, * - candidate default, U - per-user static
>>>> route
>>>> o - ODR, P - periodic downloaded static route
>>>>
>>>> Gateway of last resort is not set
>>>>
>>>> 1.0.0.0/24 is subnetted, 1 subnets
>>>> O 1.1.0.0 [110/65] via 10.1.1.2, 00:02:07, Serial0/0
>>>> 2.0.0.0/24 is subnetted, 1 subnets
>>>> O 2.2.0.0 [110/65] via 20.1.1.2, 00:02:07, Serial0/1
>>>> 100.0.0.0/24 is subnetted, 4 subnets
>>>> C 100.100.0.0 is directly connected, Loopback0
>>>> C 100.100.1.0 is directly connected, Loopback1
>>>> C 100.100.2.0 is directly connected, Loopback2
>>>> C 100.100.3.0 is directly connected, Loopback3
>>>> 20.0.0.0/30 is subnetted, 1 subnets
>>>> C 20.1.1.0 is directly connected, Serial0/1
>>>> 10.0.0.0/30 is subnetted, 1 subnets
>>>> C 10.1.1.0 is directly connected, Serial0/0
>>>> 12.0.0.0/30 is subnetted, 1 subnets
>>>> O 12.1.1.0 [90/128] via 20.1.1.2, 00:02:08, Serial0/1
>>>> [90/128] via 10.1.1.2, 00:02:08, Serial0/0
>>>>
>>>> When R1's Router-ID is Lower than R2 and R1 hasnt reached the FULL state
>>>> with R0. The route thru R2 is shown with A.D of 90(specified in the
>>>> config.]
>>>> R0#sir
>>>> Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
>>>> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
>>>> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
>>>> E1 - OSPF external type 1, E2 - OSPF external type 2
>>>> i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>>> level-2
>>>> ia - IS-IS inter area, * - candidate default, U - per-user static
>>>> route
>>>> o - ODR, P - periodic downloaded static route
>>>>
>>>> Gateway of last resort is not set
>>>>
>>>> 2.0.0.0/24 is subnetted, 1 subnets
>>>> O 2.2.0.0 [110/65] via 20.1.1.2, 00:00:09, Serial0/1
>>>> 100.0.0.0/24 is subnetted, 4 subnets
>>>> C 100.100.0.0 is directly connected, Loopback0
>>>> C 100.100.1.0 is directly connected, Loopback1
>>>> C 100.100.2.0 is directly connected, Loopback2
>>>> C 100.100.3.0 is directly connected, Loopback3
>>>> 20.0.0.0/30 is subnetted, 1 subnets
>>>> C 20.1.1.0 is directly connected, Serial0/1
>>>> 10.0.0.0/30 is subnetted, 1 subnets
>>>> C 10.1.1.0 is directly connected, Serial0/0
>>>> 12.0.0.0/30 is subnetted, 1 subnets
>>>> O 12.1.1.0 [90/128] via 20.1.1.2, 00:00:09, Serial0/1
>>>>
>>>> After R0 -- R1 FULL state
>>>> R0#sir
>>>> Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
>>>> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
>>>> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
>>>> E1 - OSPF external type 1, E2 - OSPF external type 2
>>>> i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>>> level-2
>>>> ia - IS-IS inter area, * - candidate default, U - per-user static
>>>> route
>>>> o - ODR, P - periodic downloaded static route
>>>>
>>>> Gateway of last resort is not set
>>>>
>>>> 1.0.0.0/24 is subnetted, 1 subnets
>>>> O 1.1.0.0 [110/65] via 10.1.1.2, 00:00:01, Serial0/0
>>>> 2.0.0.0/24 is subnetted, 1 subnets
>>>> O 2.2.0.0 [110/65] via 20.1.1.2, 00:00:01, Serial0/1
>>>> 100.0.0.0/24 is subnetted, 4 subnets
>>>> C 100.100.0.0 is directly connected, Loopback0
>>>> C 100.100.1.0 is directly connected, Loopback1
>>>> C 100.100.2.0 is directly connected, Loopback2
>>>> C 100.100.3.0 is directly connected, Loopback3
>>>> 20.0.0.0/30 is subnetted, 1 subnets
>>>> C 20.1.1.0 is directly connected, Serial0/1
>>>> 10.0.0.0/30 is subnetted, 1 subnets
>>>> C 10.1.1.0 is directly connected, Serial0/0
>>>> 12.0.0.0/30 is subnetted, 1 subnets
>>>> O 12.1.1.0 [110/128] via 20.1.1.2, 00:00:02, Serial0/1
>>>> [110/128] via 10.1.1.2, 00:00:02, Serial0/0
>>>>
>>>>
>>>> I haven't beeen able to reason why this happens..? but it happens.! and
>>>> "Say
>>>> you have 2 paths to a destination network, then the A.D of the route
>>>> thru
>>>> the Nieghbour with the lowest Router-ID is applied to the other routes
>>>> thru
>>>> different nieghbors or paths" I have no idea why..!
>>>>
>>>> any ideas?
>>>>
>>>> when R
>>>> 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
>>>> Sent from Bangalore, KA, India
>>>>
>>>> On Fri, May 22, 2009 at 5:52 AM, Chris Breece <cbreece1_at_gmail.com>
>>>> wrote:
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>> Hey Divin,
>>>>>
>>>>> I ran into this same thing on Wednesday. I tried to use the distance
>>>>> command in the same fashion. I wanted to prefer some routes to go to
>>>>> one
>>>>> neighbor instead of another. I got the same results as you show below.
>>>>> If
>>>>> there was another available next-hop, it changed the AD for both paths.
>>>>>
>>>>> I ended up doing "distance 255 1.1.1.1 0.0.0.0 Named_ACL". This
>>>>> effectively
>>>>> deleted one of the routes out of my routing table. In that scenario, I
>>>>> lost
>>>>> my redundant route... but it seemed to fit the requirements.
>>>>>
>>>>> I don't know that its a bug, but I can confirm another human being saw
>>>>> the
>>>>> same issue you did :P
>>>>>
>>>>> Chris
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Thu, May 21, 2009 at 4:13 PM, Divin Mathew John <
>>>>> divinjohn_at_gmail.com
>>>>>
>>>>>
>>>>>> wrote:
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> I have this problem. i am trying to change the A.D of a particular
>>>>>> path
>>>>>> in
>>>>>> OSPF using distance command. My config is pasted below.
>>>>>> Topology
>>>>>>
>>>>>> R0
>>>>>> interface Loopback0
>>>>>> ip address 100.100.0.100 255.255.255.0
>>>>>> !
>>>>>> interface Loopback1
>>>>>> ip address 100.100.1.100 255.255.255.0
>>>>>> !
>>>>>> interface Loopback2
>>>>>> ip address 100.100.2.100 255.255.255.0
>>>>>> !
>>>>>> interface Loopback3
>>>>>> ip address 100.100.3.100 255.255.255.0
>>>>>> !
>>>>>> interface Serial0/0
>>>>>> ip address 10.1.1.1 255.255.255.252
>>>>>> serial restart-delay 0
>>>>>> !
>>>>>> interface Serial0/1
>>>>>> ip address 20.1.1.1 255.255.255.252
>>>>>> serial restart-delay 0
>>>>>> !
>>>>>>
>>>>>> router ospf 1
>>>>>> log-adjacency-changes
>>>>>> network 10.1.1.1 0.0.0.0 area 0
>>>>>> network 20.1.1.1 0.0.0.0 area 0
>>>>>> network 100.100.0.100 0.0.0.0 area 0
>>>>>> network 100.100.1.100 0.0.0.0 area 0
>>>>>> network 100.100.2.100 0.0.0.0 area 0
>>>>>> network 100.100.3.100 0.0.0.0 area 0
>>>>>> distance 90 12.1.1.1 0.0.0.0 SELECT_12.1.1.0_from_R1
>>>>>> !
>>>>>> ip access-list standard SELECT_12.1.1.0_from_R1
>>>>>> permit 12.1.1.0
>>>>>>
>>>>>> R0#show ip ospf neighbor
>>>>>>
>>>>>> Neighbor ID Pri State Dead Time Address
>>>>>> Interface
>>>>>> 20.1.1.2 0 FULL/ - 00:00:37 20.1.1.2
>>>>>> Serial0/1
>>>>>> 12.1.1.1 0 FULL/ - 00:00:33 10.1.1.2
>>>>>> Serial0/0
>>>>>>
>>>>>> R0#sir
>>>>>> Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
>>>>>> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
>>>>>> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
>>>>>> E1 - OSPF external type 1, E2 - OSPF external type 2
>>>>>> i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>>>>> level-2
>>>>>> ia - IS-IS inter area, * - candidate default, U - per-user static
>>>>>> route
>>>>>> o - ODR, P - periodic downloaded static route
>>>>>>
>>>>>> Gateway of last resort is not set
>>>>>>
>>>>>> 1.0.0.0/24 is subnetted, 1 subnets
>>>>>> O 1.1.0.0 [110/65] via 10.1.1.2, 00:01:35, Serial0/0
>>>>>> 2.0.0.0/32 is subnetted, 1 subnets
>>>>>> O 2.2.0.2 [110/65] via 20.1.1.2, 00:01:35, Serial0/1
>>>>>> 100.0.0.0/24 is subnetted, 4 subnets
>>>>>> C 100.100.0.0 is directly connected, Loopback0
>>>>>> C 100.100.1.0 is directly connected, Loopback1
>>>>>> C 100.100.2.0 is directly connected, Loopback2
>>>>>> C 100.100.3.0 is directly connected, Loopback3
>>>>>> 20.0.0.0/30 is subnetted, 1 subnets
>>>>>> C 20.1.1.0 is directly connected, Serial0/1
>>>>>> 10.0.0.0/30 is subnetted, 1 subnets
>>>>>> C 10.1.1.0 is directly connected, Serial0/0
>>>>>> * 12.0.0.0/30 is subnetted, 1 subnets
>>>>>> O 12.1.1.0 [90/128] via 20.1.1.2, 00:01:36, Serial0/1
>>>>>> [90/128] via 10.1.1.2, 00:01:36, Serial0/0*
>>>>>>
>>>>>> according to my distance command only the route from R1 should have
>>>>>> changed
>>>>>> its A.D. but here even though i specified the ROUTER-ID of the router
>>>>>> whose
>>>>>> path i need to change the A.D it doesn't change that... it changes the
>>>>>> A.D
>>>>>> of all paths to the destination..! is this a BUG?
>>>>>>
>>>>>>
>>>>>> 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
>>>>>> Sent from Bangalore, KA, India
>>>>>>
>>>>>>
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Received on Fri May 22 2009 - 19:33:21 ART