Re: OSPF discontiguous areas

Andy,

We labbed it, it actually does work... it means they are different areas
then.

Thanks Andy...

On Sat, Sep 5, 2009 at 2:22 PM, Andy Reid <ccie_at_reid.it> wrote:

> Hi Molomo,
>
> Yes that will work just fine.
> You can lab it yourself with just 3 routers:
>
> R2----area 1---R5---area 0 (loopback 0)---area 1-----R4
>
> I took a break out of the exciting world of multicast to lab it myself:
>
> R2:
> interface Loopback0
> ip address 2.2.2.2 255.0.0.0
> !
> interface Serial0/0
> no ip address
> encapsulation frame-relay
> no dce-terminal-timing-enable
> !
> interface Serial0/0.25 point-to-point
> ip address 10.1.25.2 255.255.255.0
> ip pim sparse-mode
> frame-relay interface-dlci 205
> !
> router ospf 1
> log-adjacency-changes
> network 0.0.0.0 255.255.255.255 area 1
> end
>
> R5:
> interface Loopback0
> ip address 5.5.5.5 255.0.0.0
> !
> interface Serial0/0
> no ip address
> encapsulation frame-relay
> !
> interface Serial0/0.52 point-to-point
> ip address 10.1.25.5 255.255.255.0
> ip pim sparse-mode
> frame-relay interface-dlci 502 !
> !
> interface Serial0/0.54 point-to-point
> ip address 10.1.45.5 255.255.255.0
> ip pim sparse-mode
> frame-relay interface-dlci 504 !
> router ospf 1
> log-adjacency-changes
> network 5.5.5.5 0.0.0.0 area 0
> network 10.0.0.0 0.255.255.255 area 1
> end
>
> R4:
> interface Loopback0
> ip address 4.4.4.4 255.0.0.0
> !
> interface Serial0/0
> no ip address
> encapsulation frame-relay
> no dce-terminal-timing-enable
> !
> interface Serial0/0.45 point-to-point
> ip address 10.1.45.4 255.255.255.0
> ip pim sparse-mode
> frame-relay interface-dlci 405 !
> router ospf 1
> log-adjacency-changes
> network 0.0.0.0 255.255.255.255 area 1
> end
>
> The end result is area 0 on a stick :)
>
> R5#show ip os ne
> Neighbor ID Pri State Dead Time Address Interface
> 4.4.4.4 0 FULL/ - 00:00:32 10.1.45.4
> Serial0/0.54
> 2.2.2.2 0 FULL/ - 00:00:37 10.1.25.2
> Serial0/0.52
>
> R5#show ip route ospf
> 2.0.0.0/32 is subnetted, 1 subnets
> O 2.2.2.2 [110/65] via 10.1.25.2, 00:07:09, Serial0/0.52
> 4.0.0.0/32 is subnetted, 1 subnets
> O 4.4.4.4 [110/65] via 10.1.45.4, 00:07:09, Serial0/0.54
>
>
> R2#show ip route ospf
> 4.0.0.0/32 is subnetted, 1 subnets
> O 4.4.4.4 [110/129] via 10.1.25.5, 00:07:38, Serial0/0.25
> 5.0.0.0/32 is subnetted, 1 subnets
> O IA 5.5.5.5 [110/65] via 10.1.25.5, 00:07:38, Serial0/0.25
> 10.0.0.0/24 is subnetted, 2 subnets
> O 10.1.45.0 [110/128] via 10.1.25.5, 00:07:38, Serial0/0.25
>
> R2#ping 4.4.4.4
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 112/127/176 ms
>
> R4#show ip route ospf
> 2.0.0.0/32 is subnetted, 1 subnets
> O 2.2.2.2 [110/129] via 10.1.45.5, 00:08:18, Serial0/0.45
> 5.0.0.0/32 is subnetted, 1 subnets
> O IA 5.5.5.5 [110/65] via 10.1.45.5, 00:08:18, Serial0/0.45
> 10.0.0.0/24 is subnetted, 2 subnets
> O 10.1.25.0 [110/128] via 10.1.45.5, 00:08:18, Serial0/0.45
>
> Also check out this Cisco link:
> http://www.cisco.com/en/US/tech/tk365/technologies_q_and_a_item09186a0080094704.shtml
>
> regards Andy
>
>
> Molomo wrote:
>
>> Experts,
>>
>> I would like to know if the setup below is valid, and whether R1 & R4 will
>> be able to reach each other.
>>
>>
>> R1---area 1-----R2---area 0-----R3----area 1-----R4
>>
>>
>> Regards,
>> Molomo
>>
>>
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Received on Sat Sep 05 2009 - 15:28:01 ART