From: mannan venkatesan (venkat_m@xxxxxxx)
Date: Thu Oct 19 2000 - 11:24:01 GMT-3
Hi,
here the configs,
R1:
!
interface Ethernet0
ip address 12.0.0.1 255.0.0.0
!
interface Serial0
no ip address
encapsulation frame-relay
!
interface Serial0.1 point-to-point
ip address 10.1.0.2 255.255.0.0
ip ospf network point-to-multipoint
frame-relay interface-dlci 100
router ospf 10
network 10.0.0.0 0.255.255.255 area 0
R2:
interface Ethernet0
ip address 11.0.0.1 255.0.0.0
!
interface Serial0
ip address 10.1.0.1 255.255.0.0
encapsulation frame-relay
ip ospf network Point-to-multipoint
frame-relay map ip 10.1.0.1 106
router ospf 10
network 10.0.0.0 0.255.255.255 area 0
The reason I used sub-if in R1 is I wanted to try a hub-spokes scenario once
I am done with this config and I used 'IP OSPF NETWORK POIN-TO-MULTIPOINT'
because by default the ospf network type in S0 of R2 was 'Broadcast' and
some reason I couldn't ping one router to other without FR map command. 'sh
ip ospf nei' command in R2 showed,
Neighbor ID Pri State Dead Time Address Interface
10.1.0.2 1 INIT/- 00:01:39 10.1.0.2 Serial0
'debug ip ospf packet' showed both routers sending out multicast packets to
form adj.
-----Original Message-----
From: Rogell, Dennis [mailto:Dennis_Rogell@milgo.com]
Sent: Thursday, October 19, 2000 10:10 AM
To: 'mannan venkatesan'
Subject: RE: OSPF Problem - Area BACKBONE(0) (Inactive)
Can you post your configs
Dennis Rogelll
Email : dennis_rogell@milgo,com
Phone: (954) 426-2581
> -----Original Message-----
> From: mannan venkatesan [SMTP:venkat_m@ins.com]
> Sent: Thursday, October 19, 2000 06:42
> To: 'Justin Menga'; ccielab@groupstudy.com
> Subject: RE: OSPF Problem - Area BACKBONE(0) (Inactive)
>
> Hi,
> Thank you all for your feedbacks. Last night I was trying to configure a
> simple P-O-P ospf config. over FR which I have done many times before. But
> I
> couldn't get it work. I was able to ping from one router to other. In R1,
> sh
> ip ospf showed 'Area BACKBONE(0) (Inactive) '. I don't understand why area
> 0
> is inactive. Can someone help me?
>
> Thanks,
> Mannan
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Justin Menga
> Sent: Wednesday, October 18, 2000 7:08 PM
> To: 'mannan venkatesan'; ccielab@groupstudy.com
> Subject: RE: OSPF Problem
>
>
> Network was broken because R3 is the DR and can't communicate with R2 for
> the Type 2 LSA. Try using ip ospf priority 0 on R3 on the subinterface to
> force R1 to become the DR.
>
> The hub always should be the DR..........
>
> Regards,
>
> Justin Menga MCSE+I CCNP CCSE ASE
> WAN Specialist
> Computerland New Zealand
> PO Box 3631, Auckland
> DDI: (+64) 9 360 4864 Mobile: (+64) 25 349 599
> mailto: justin.menga@computerland.co.nz
>
>
> -----Original Message-----
> From: mannan venkatesan [mailto:venkat_m@ins.com]
> Sent: Wednesday, 18 October 2000 4:07 a.m.
> To: ccielab@groupstudy.com
> Subject: OSPF Problem
>
>
> Hi,
> I was playing in ospf over FR lab and came across an interesting problem(I
> was trying to simulate the problem we had in our client production
> network).
> I configured R1 as hub (sub-ifs) and R2 and R3 as spoke (physical
> interface). Here the config,
>
> R1 :
> interface Serial0.1 point-to-point
> ip address 10.1.0.1 255.255.0.0
> ip ospf network broadcast
> frame-relay interface-dlci 100
> !
> interface Serial0.2 point-to-point
> ip address 10.2.0.1 255.255.0.0
> ip ospf network Point-to-multipoint
> frame-relay interface-dlci 103
>
> router ospf 10
> network 10.0.0.0 0.255.255.255 area 0
>
> R2 :
> interface Serial0
> ip address 10.1.0.2 255.255.0.0
> encapsulation frame-relay
> ip ospf network Point-to-multipoint
> frame-relay map ip 10.1.0.1 106
>
> router ospf 10
> network 10.0.0.0 0.255.255.255 area 0
>
> R3:
> interface Serial0
> ip address 10.2.0.2 255.255.0.0
> encapsulation frame-relay
> ip ospf network Point-to-multipoint
> frame-relay map ip 10.2.0.1 106
>
> router ospf 10
> network 10.0.0.0 0.255.255.255 area 0
>
> It worked fine with this config. Then I changed OSPF network type to
> "Broadcast" in s0 of R3 and s0.2 of R1. R3 became DR and R1 became BDR.
> After I changed OSPF network type to "Broadcast" in s0.1 of R1 and s0 of
> R2.
> As soon as I entered network type 'broadcast' in R2, the network broke. I
> couldn't access any of the routers for 5 minutes.
>
> Now 'sh ip ospf nei' command shows,
>
> R1:
> Neighbor ID Pri State Dead Time Address
> Interface
> 10.1.0.2 1 FULL/BDR 00:00:39 10.1.0.2
> Serial0.1
> 10.2.0.2 1 FULL/BDR 00:00:37 10.2.0.2
> Serial0.2
>
> R2:
> Neighbor ID Pri State Dead Time Address
> Interface
> 10.2.0.1 1 FULL/DR 00:00:31 10.1.0.1 Serial0
>
> R3:
> Neighbor ID Pri State Dead Time Address
> Interface
> 10.2.0.1 1 FULL/DR 00:00:39 10.2.0.1 Serial0
>
> I know DR and BDR election was going on, but why the network broke? During
> election, routers multicast packets and we have only 3 routers. So, what
> traffic did the routers send here? Can I have multiple OSPF network in one
> broadcast medium? Can someone clarify my questions? Think I am missing
> something here.
>
> Thanks,
> Mannan Venkatesan
>
>
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