From: Night War (nightwar@gmail.com)
Date: Mon Dec 25 2006 - 06:07:29 ART
Hello Group,
I understand that p2m and non_broadcast are not compatible but why do they
form neighbor relationship and also show that they have exchanged database
and are in FULL state. That is what I'm not able to understand. If the sh ip
ospf neighbor command says that adjacencies have formed and the routers are
in 2-WAY state then I can have a clue that something is wrong
R1 OSPF Network type : point-to-multipoint
R2 OSPF Network type : Non_Broadcast
If I'm having such a situation in my exam and if I forget to look at the
network types on the routers in the NBMA network I would be really confused.
I tried to debug ospf and I've no error messages or any problem while
forming my neighbor relationship. Do we have any specific debug commands to
know whether the network types are mismatch.
I've also copied show ip ospf database output from both the routers when
they are not exchanging routes but still neighbors and Full state.
R1#sh ip ospf database
OSPF Router with ID (150.1.1.1) (Process ID 100)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
150.1.1.1 150.1.1.1 48 0x80000002 0x006573 2
150.1.2.2 150.1.2.2 53 0x80000002 0x00413D 1
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
150.1.1.0 150.1.1.1 49 0x80000001 0x007693
150.1.2.0 150.1.2.2 14 0x80000001 0x005EA8
Router Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Link count
150.1.1.1 150.1.1.1 54 0x80000001 0x00065F 1
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
155.1.0.1 150.1.1.1 49 0x80000001 0x002CD9
R1#
R2(config)#do sh ip ospf database
OSPF Router with ID (150.1.2.2) (Process ID 100)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
150.1.1.1 150.1.1.1 229 0x80000002 0x006573 2
150.1.2.2 150.1.2.2 232 0x80000002 0x00413D 1
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
150.1.1.0 150.1.1.1 230 0x80000001 0x007693
150.1.2.0 150.1.2.2 193 0x80000001 0x005EA8
Router Link States (Area 2)
Link ID ADV Router Age Seq# Checksum Link count
150.1.2.2 150.1.2.2 198 0x80000002 0x00EA74 1
R2(config)#
Hello ian,
I'm fine ... How are you ? I tried to reboot the routers with the same
configs I've mentioned but the same result unable to exchange routes.
I've one more question.
Referring to the same topology when
R1 OSPF Network type: point-to-multipoint
R2 OSPF Network type: point-to-point
I see that a host a route is added to R2 for the R1 serial 1/0 interface IP
Address. For eg:
O 155.1.0.1/32 [110/64] via 155.1.0.1, 00:00:15, Serial1/0
This happens most of the time if the OSPF network-type is
Point-to-Multipoint. Do we have any command to filter or not advertise to
the neighbor routers that are on the end of point-to-multipoint interfaces.
I think host route is not at all necessary as without knowing how to reach
to 155.1.0.1 I would not form OSPF neighbor relationship at the first place.
I think we have no peer neighbor-route command to disable host route in ppp
point-to-point links do we have any commands or option to disable the host
route in the frame-relay networks.
Thanks for you reply and spending your valuable time on this stupid
configuration.
Can any one give me some good titles to learn more about Advanced OSPF
routing and designing the same.
Regards
Fahad
On 12/25/06, Night War <nightwar@gmail.com> wrote:
>
> Hello Group !!
>
> Happy holidays to all members in GS !! Happy Christmas and advance New
> Year wishes to all !!
>
> I've a simple configuration shown in the topology below :
>
> loopback0 s1/0 s1/0 loopback 0
> 150.1.1.1------------------- R1 -------------()------------ R2
> ---------------------150.1.2.2
> area 1 .1 155.1.0.0 .2 area 2
>
> area 0
> (hub) (spoke)
>
>
> I'm having a problem and I would be glad if someone could explain to me
> the cause of the problem and why this problem is happening at the first
> place.
>
> I've configured and implemented OSPF based on the configuration below for
> R1 and R2:
>
> R1 OSPF Config and Serial 1/0 config:
>
> router ospf 100
> router-id 150.1.1.1
> network 150.1.0.0 0.0.255.255 area 1
> network 155.1.0.1 0.0.0.0 area 0
>
> interface Serial1/0
> ip address 155.1.0.1 255.255.255.0
> encapsulation frame-relay
> ip ospf network point-to-multipoint
> ip ospf hello-interval 10
> ip ospf priority 255
> frame-relay map ip 155.1.0.2 102 broadcast
> no frame-relay inverse-arp
> end
>
>
> R2 OSPF and Serial1/0 config:
>
> router ospf 100
> router-id 150.1.2.2
> network 150.1.0.0 0.0.255.255 area 2
> network 155.1.0.2 0.0.0.0 area 0
>
> interface Serial1/0
> ip address 155.1.0.2 255.255.255.0
> encapsulation frame-relay
> ip ospf hello-interval 10
> ip ospf priority 0
> frame-relay map ip 155.1.0.1 301 broadcast
> no frame-relay inverse-arp
> end
>
>
> I've purposely not give any network type on the interface of Serial 1/0 of
> router 2 (R2) the spoke. I've given the network type of point-to-multipoint
> in the Hub router of the frame-relay cloud as I might add more routers to
> the frame-relay cloud.
>
> The hello-interval and dead-interval of both R1 and R2 are the same on
> both routers namely 10 secs and 30 secs respectively.
>
> On using the configuration mentioned above for R2 and R1 I'm able to form
> adjacency and both R1 and R2 have established neighbor relationship. The sh
> ip ospf neighbor command on both the routers are below:
>
> R1#sh ip ospf neighbor
>
> Neighbor ID Pri State Dead Time Address
> Interface
> 150.1.2.2 0 FULL/ - 00:00:34 155.1.0.2
> Serial1/0
>
>
> R2#sh ip ospf neighbor
>
> Neighbor ID Pri State Dead Time Address
> Interface
> 150.1.1.1 255 FULL/DR 00:00:35 155.1.0.1
> Serial1/0
>
>
>
> Now having said all that I've done and showing you my outputs I'm having
> the following problem. Both the routers R1 and R2 are not able to learn each
> others loopback interface which they are advertising into the ospf domain.
> R1 is advertising 150.1.1.1 as area 1 and R2 is advertising 150.1.2.2 as
> area 2. Both the routers R1 and R2 are ABR's as they have atleast one
> interface in area 0.
>
> Both the routers are not learning any routes from their neighbor even if I
> add another loopback network into area 0.
>
> the solution to the above problem is to add "ip ospf network
> point-to-point" on serial 1/0 of the spoke router R2. everything goes well
> after applying this command. both routers are learning all the routes. I
> would like to know the reason why these routers don't learn the routes prior
> to applying the "ip ospf network point-to-point" on serial 1/0 of R2. What
> is the logic for such a behavior ?
>
> Thanks
> Fahad.
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