RE: [OSPF] OSPF GR query

Hi Ace 

But reaching to a FULL state is not one of the conditions for Helper to
quit Helper mode, I guess a Helper who has reached 
to FULL state with its restarting router will wait for Grace LSAs to be
flushed or GR timeout to happen for exiting Helper mode.

Regards
Aamir

-----Original Message-----
From: Acee Lindem [mailto:acee@cisco.com] 
Sent: Thursday, October 05, 2006 8:00 PM
To: Khan Amir-G20247
Cc: ospf@ietf.org
Subject: Re: [OSPF] OSPF GR query

Hello Amir,

Khan Amir-G20247 wrote:
>  
>
> Hi
>
> I have query related to OSPF Graceful Restart. 
>
> Consider this scenario: 
>
>  
>
> - Three Routers R1, R2 and R3 connected via Broadcast networks. 
>
>  
>
>  
>
>  
>
> - Where R1 is a DR on both the segments, where as R2 and R3 are in 
> DR-other
> - Now R1 wants to perform GR, R2 and R3 agrees to be its Helpers. 
> - Now after restart R1 will try to form adjacency with both R2 and R3.

> - Lets say R1 and R2 had become FULL, while R1 and R3 had reached
> Exstart state.   Now at this time R2 receives an LSA (any type 1-5 and
> 7, from some other router existing in the same area, not pictured 
> here) which he needs to flood to R1.
> - This will force R2 to quit Helper Status, while R1 and R3 are still 
> in process of forming adjacency.
>   
Since he has reached FULL state, he is no longer a helper router.
>
>
> Considering above scenario, my doubts are: 
>
> - How will R1 come to know that its Helper R2 has quit? 
>   
Since he has reached FULL state, he is no longer a helper router.
> - Will the adjacency between R1 and R2 needs to go down, as R2 quits 
> helper mode?
>   
No
> - Will this effect the adjacency formation of R1 and R3?
>   
No. R3 MAY exit helper status and re-originate a new router LSA if he
receives the new LSA before reaching FULL state with R1 AND he is has
strict-LSA-checking configured.

Hope this helps,
Acee
>  
>
> Regards
> Aamir
>
>  
>
>
>   
> ----------------------------------------------------------------------
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>
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