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Visitor
Posts: 4
Registered: ‎12-13-2015
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Accepted Solution

Nonstop active routing (NSR)

Question

 

I have two EX 4300 acting as a core for a building. Does NSR needed in a virtual chassis to preserve l3 routing? At the momenti only have GRES configured. I thought NSR is needed only when a device have two built in RE. 

 

Thank you 

Nils 

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Recognized Expert
Posts: 130
Registered: ‎12-10-2013
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Re: Nonstop active routing (NSR)

YES you need to enable it

it copies all realtime information of routing protocols and Session and TCP info from the RE to the backup RE, thus BGP and OSPF and other sessions will not be reinitialized when there is a RE switchover

 

regards

 

alexander

 

Distinguished Expert
Posts: 610
Registered: ‎05-02-2011
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Re: Nonstop active routing (NSR)

You need GRES/NSR only when you have dual RE.

 

Each of these two features does something different with regards to interfaces states or routing protocols states during a RE switchover.

 

Here is something about GRES:

 

https://www.juniper.net/documentation/en_US/junos/topics/concept/gres-overview.html

 

And about NSR:

 

https://www.juniper.net/documentation/en_US/junos/topics/concept/nsr-overview.html


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Visitor
Posts: 4
Registered: ‎12-13-2015
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Re: Nonstop active routing (NSR)

Parau, 

 

Just to be clear Dual RE could be a virtual chassis as well as a single router with two RE? Am i correct?

 

Nils 

Distinguished Expert
Posts: 610
Registered: ‎05-02-2011
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Re: Nonstop active routing (NSR)

Yes, it can be a VC/VCF with dual RE or chassis based device with dual RE.