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New Member

Enabling NSF with virtual-links

I'm enabling VSS on a pair of 6500's.  The documentation I have recommends enabling NSF in the OSPF process which shouldn't be too hard, except further reading about NSF mentions it doesn't work with virtual links. I have virtual links.  What I'm trying to figure out is if I can safely enable NSF in OSPF so I get the benefits with my other areas without it breaking my virtual links.

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Cisco Employee

Hi,Restrictions for OSPF NSF


Restrictions for OSPF NSF

OSPF NSF for virtual links is not supported.

All OSPF networking devices on the same network segment must be NSF-aware (that is, running an NSF software image).

OSPF NSF for sham links is not supported.




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New Member

Hi Inayath, Thank you for the

Hi Inayath,


Thank you for the reply. 


I'm trying to determine whether it will break my virtual-linked areas outright if I enable it or if I just lose the benefit of NSF for the areas I have that are using a virtual link. 

I'd like to enable it if possible without causing an outage.


New Member

HiI want to enable NSF in


I want to enable NSF in EIGRP in 6513 (VSS) for SSO redundancy

I want to know should i also enable NSF in all EIGRP neighbors as well.

Core switch has eigrp neighbors which are User distribution switches (3560E-12SD-E).

So just want to know that enabling NSF in core switch (6513) will not cause any service interruption for the networks which is advertise in EIGRP . I also have redistribute static routes in core switch EIGRP.

Appreciate your repsonse

New Member

For anyone in the same

For anyone in the same position,  I implemented this last night.  After turning NSF on in my OSPF process, I waited for alarms to start rolling in from my networks reachable via virtual link.  None came. 

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