[j-nsp] MX960 Redundant RE problem

[Mohammad]

Hi All

Thank you for your support, most probably what we are gonna do is:
	- try turning GRES/NSR on/off
	- upgrade to 10.4R8.5 or 10.4R9
Currently we are waiting JTAC response.
I'll let you once it is solved.

Thank you again
Mohammad Salbad

-----Original Message-----
From: Stefan Fouant [mailto:sfouant at shortestpathfirst.net] 
Sent: Wednesday, February 15, 2012 11:08 PM
To: Daniel Roesen
Cc: Morgan McLean; juniper-nsp at puck.nether.net; Mohammad
Subject: Re: MX960 Redundant RE problem

I was referring more to a bug in hardware... Bad memory, etc.

Stefan Fouant
JNCIE-SEC, JNCIE-SP, JNCIE-ER, JNCI
Technical Trainer, Juniper Networks

Follow us on Twitter @JuniperEducate

Sent from my iPad

On Feb 15, 2012, at 1:56 PM, Daniel Roesen <dr at cluenet.de> wrote:

> On Wed, Feb 15, 2012 at 12:24:50PM -0500, Stefan Fouant wrote:
>> The cool thing is the Backup RE is actually listening to all the 
>> control plane messages coming on fxp1 destined for the Master RE and 
>> formulating it's own decisions, running its own Dijkstra, BGP Path 
>> Selection, etc. This is a preferred approach as opposed to simply 
>> mirroring routing state from the Primary to the Backup is because it 
>> eliminates fate sharing where there may be a bug on the Primary RE, 
>> we don't want to create a carbon copy of that on the Backup.
> 
> I don't really buy that argument. Running the same code with the same 
> algorithm against the same data usually leads to the same results.
> You'll get full bug redundancy - I'd expect RE crashing simultaneously.
> Did NSR protect from any of the recent BGP bugs?
> 
> The advantage I see are less impacting failovers in case of a) 
> hardware failures of active RE, or b) data structure corruption 
> happening on both REs [same code => same bugs], but eventually leading 
> to a crash of the active RE sooner than on the backup RE, or c) race 
> conditions being triggered sufficiently differently timing-wise so 
> only active RE crashes.
> 
> Am I missing something?
> 
> Best regards,
> Daniel
> 
> --
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