Re: OSPF NEIGHBOUR ON TUNNEL

From: Mohamed M Moustafa (mmma@gawab.com)
Date: Wed Aug 15 2007 - 05:36:45 ART


Hi,

The idea in this scenario is that the routers will send both routes via
OSPF, the desired routes and the next-hop (ip unnumbered) address and
everything will work out, please check it below:

Rack1R4#show run int s1/1

Building configuration...

Current configuration : 88 bytes
!
interface Serial1/1
 ip address 155.1.45.4 255.255.255.0
 serial restart-delay 0
end

Rack1R4#show run int tun 1

Building configuration...

Current configuration : 106 bytes

!
interface Tunnel1
 ip unnumbered Loopback1
 tunnel source Serial1/1
 tunnel destination 155.1.45.5
end

 Rack1R4#show run int loopback 1

Building configuration...

 Current configuration : 65 bytes

!
interface Loopback1
 ip address 150.1.4.4 255.255.255.255

Rack1R4#show run | be router ospf

router ospf 1
 log-adjacency-changes
 network 150.1.4.4 0.0.0.0 area 0

!
Rack1R5#show run int s1/1
Building configuration...

Current configuration : 88 bytes

!
interface Serial1/1
 ip address 155.1.45.5 255.255.255.0
 serial restart-delay 0
end

 Rack1R5#show run int tun 1
Building configuration...

Current configuration : 106 bytes

!
interface Tunnel1
 ip unnumbered Loopback1
 tunnel source Serial1/1
 tunnel destination 155.1.45.4
end

 Rack1R5#show run int loopback 1
Building configuration...
 

Current configuration : 65 bytes
!
interface Loopback1
 ip address 150.1.5.5 255.255.255.255
end

Rack1R5#show run | be router ospf
router ospf 1
 log-adjacency-changes
 network 150.1.5.5 0.0.0.0 area 0
 network 155.1.5.5 0.0.0.0 area 1

Rack1R5#show ip int br | inc 155.1.5
Ethernet0/0 155.1.58.5 YES NVRAM up
up
Ethernet0/1 155.1.5.5 YES NVRAM up
up

Rack1R4#show ip route ospf

     155.1.0.0/24 is subnetted, 4 subnets

O IA 155.1.5.0 [110/11121] via 150.1.5.5, 00:02:19, Tunnel1
     150.1.0.0/32 is subnetted, 2 subnets

O 150.1.5.5 [110/11112] via 150.1.5.5, 00:02:19, Tunnel1 <<<====

Jian Gu <guxiaojian@gmail.com> wrote on 14 Aug 2007, 11:56 PM:
Subject: Re: OSPF NEIGHBOUR ON TUNNEL
>This is not specific to (GRE) tunnel, it is common to all point-to-point
>links, you can have OSPF adj over a serial link with ip unnumbered address
>with different subnet masks.
>
>When IP unnumbered is configured, routes learned through the IP unnumbered
>interface have the interface as the next hop instead of the source address
>of the routing update.
>
>On 8/14/07, NITIN NITIN <ccie_study_123@yahoo.com> wrote:
>>
>> HI EXPERTS,
>>
>> I have a querry in mind since long ,
>>
>> Like I put on tunnel interrface ip unnmber LOOP 0
>>
>> on R1 --OSPF-- R2
>>
>> Tunnel on R1 and R2
>>
>> R1 LOOP 0 - 150.1.1.1/24
>> R2 LOOP 0 - 150.1.2.2/24
>>
>> these are not in same subnet still ospf neighborship on tunnel comes up
>> why ?
>>
>>
>>
>> ---------------------------------
>> Building a website is a piece of cake.
>> Yahoo! Small Business gives you all the tools to get online.
>>
>> ---------------------------------
>> Shape Yahoo! in your own image. Join our Network Research Panel today!
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>
>_______________________________________________________________________
>Subscription information may be found at:
>http://www.groupstudy.com/list/CCIELab.html
>

---------------------------------------------
Free POP3 Email from www.Gawab.com
Sign up NOW and get your account @gawab.com!!



This archive was generated by hypermail 2.1.4 : Sat Sep 01 2007 - 11:32:11 ART