Will configuring OSPF NSF cause an outage / adjacency lost?

[MICHAEL TJANDRA]

Hi all,

Got a question since I won't be able to test on lab,

Will configuring OSPF NSF cause an outage / adjacency lost to the OSPF neighbor

many thanks in advance.

[John Blakley]

Michael,

NSF should be enabled by default. Look at "show ip ospf inter" and you should see below:

R3#sh ip ospf inter

FastEthernet0/0 is up, line protocol is up

<<< Output omitted >>>

  Cisco NSF helper support disabled

  IETF NSF helper support enabled

  Index 1/1, flood queue length 0

I had to specifically disable above (Cisco NSF helper). Reenabling:

R3(config-router)#nsf cisco helper dis

R3(config-router)#no nsf cisco helper disable

R3(config-router)#do sh ip ospf inter | inc FastEth|NSF

FastEthernet0/0 is up, line protocol is up

  Cisco NSF helper support enabled

  IETF NSF helper support enabled

The adjacencies didn't come down. You also may want to refer to this article under "Disabling NSF Awareness." It also states that it's enabled by default.

http://www.cisco.com/en/US/docs/ios/12_2t/12_2t15/feature/guide/ftosnsfa.html

HTH,
John

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[MICHAEL TJANDRA]

Thanks John,

Indeed it should be per default enabled, but I think someone disabled it for some reason or by mistake.

Many thanks for testing and your answer, it really answered my question.

kind regards,

Michael