What does 'IP Routing is NSF aware' mean?

[grapevine]

I just issued show ip protocols in our company router and it showed the below output.

Switch#show ip protocols

*** IP Routing is NSF aware ***

Why does it not show any protocols / routes? Can some one explain

[Reza Sharifi]

Why does it not show any protocols / routes? Can some one explain

The router may not be running any routing protocols.

[devils_advocate]

Switch#show ip protocols

*** IP Routing is NSF aware ***

Are you sure you have run this command on a Router and not a Switch?

[grapevine]

I ran this command on an L3 switch.

Sent from Cisco Technical Support iPhone App

[devils_advocate]

Your L3 switch is likely doing InterVlan routing.

#show ip protocols

This will show any dynamic routing protocols such as RIP, EIGRP, OSPF etc. You are probably not running any dynamic routing protocols, likely just Routing between Vlans.

#show protocols

This will show whether IP Routing is enabled globally on the L3 switch

Switch#sh protocols

Global values:

  Internet Protocol routing is enabled

[Ankur Arora]

Hi,

What do you see when you run show ip route on that switch?

Do you see any routes, any routing protocols?

IP Routing is NSF aware means that in your switch/router you have non-stop forwarding enabled, which prevents any disruption in traffic even in case of a reload as it segregates the control plane with the data plane.

It uses CEF to update the linecards about the FIB entries, which have the packet forwarding decision.

Thanks

Ankur

"Please rate the post if found useful"

[Karuga]

Thank you.

[Darth Vader]

This link is a must read to understand what NSF is:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SXF/native/configuration/guide/swcg/nsfsso.html

[Ted Haubein]

Are running IPv4 or IPv6...?

show ip protocols

show ipv6 protocols

[Abdullatif]

A device that is NSF-capable has been configured to support NSF; therefore, the device rebuilds routing information from NSF-aware or NSF-capable neighbors. Each protocol depends on CEF to continue forwarding packets during switchover while the routing protocols rebuild the routing information base (RIB) tables.