Which feature is required for graceful restart to recover from a processor failure?
Which feature is required for graceful restart to recover from a processor failure?
Stateful Switchover (SSO) is required for a graceful restart to recover from a processor failure. SSO enables the backup processor to take over seamlessly when the active processor fails, maintaining network stability and minimizing downtime. It ensures that control plane information is synchronized between the active and standby processors, allowing the device to continue forwarding packets without interruption.
C => stateful switchover
C is 100% correct
I don't know.. It's probably "A" belong this : https://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/high-availability/solution_overview_c22-487228.html GR and NSR, when coupled with SSO provide the foundation for fast recovery from a processor failure and allow the use of ISSU to perform software upgrades with little downtime. SSO is necessary to handle other non routing protocol related items needed for the router to operate following a switchover. These include syncing the complete router configuration, Cisco Express Forwarding (CEF) forwarding entries and other needed information to the standby processor.
I think it is A. Cisco Nonstop Forwarding does not maintain a continuously active control plane during switchover. Instead, the forwarding plane uses known routes while the routing protocol information is being restored after switchover. In Cisco networking devices, packet forwarding is provided by Cisco Express Forwarding. Cisco Express Forwarding maintains the FIB and uses the FIB information that was current at the time of the switchover to continue forwarding packets during a switchover. The ability to continue packet forwarding eliminates downtime during the switchover. Each protocol depends on Cisco Express Forwarding to continue forwarding packets during switchover, while the routing protocols rebuild the Routing Information Base (RIB). https://www.cisco.com/en/US/technologies/tk869/tk769/technologies_white_paper0900aecd801dc5e2.html
Totally off base. CEF is for hardware based forwarding. nothing to do with this tech.
Bro learn how to read. A is CEF, not NSF. Just because you see the word "Fowarding" doesnt mean its NSF.
Easy. C SSO
Is A: Cisco Express Forwarding for NSF A key element of NSF is packet forwarding. The OSPF protocol depends on CEF to continue forwarding packets during switchover while the routing protocols rebuild the Routing Information Base (RIB) tables. Once OSPF has converged, CEF updates the Forwarding Information Base (FIB) table and removes stale route entries. CEF then updates the line cards with the new FIB information. CEF maintains the FIB and uses the FIB information that was current at the time of a switchover to continue forwarding packets during the switchover. This feature reduces traffic interruption during the switchover.
A is correct... (although it migh seem strange...) I found this: In Cisco networking devices, packet forwarding is provided by Cisco Express Forwarding. Cisco Express Forwarding maintains the FIB and uses the FIB information that was current at the time of the switchover to continue forwarding packets during a switchover. The ability to continue packet forwarding ----------------------------------------------------------------- eliminates downtime during the switchover.----- i find it here: https://www.cisco.com/en/US/technologies/tk869/tk769/technologies_white_paper0900aecd801dc5e2.html
I say C. CEF is required for uninterrupted traffic flow, yes, but.... SSO is required for GR to work at all and this is what is asked in the question.
This is a tricky question. In the OCG pg 168 it states "Graceful Restart (GR), also known as Non-Stop Forwarding..." So Graceful Restart and Non-Stop Forwarding are one in the same. Now looking at the this site https://www.cisco.com/en/US/docs/ios/12_2t/12_2t15/feature/guide/ftbgpnsf.html it states "SSO is a prerequisite of NSF". So going by what the OCG said above, and after reading the link above, what we can conclude is SSO is a prerequisite of Graceful Restart.
You need to learn how to read. Answer A is Cisco Express Forwarding, not NON-STOP Forwarding. Two completely different things. CEF is a layer 2 switching mechanism. NSF is a protocol in junction with SSO
The correct answer is C. Stateful Switchover (SSO). Stateful Switchover (SSO) is a feature that allows graceful restart to recover from a processor failure in a network device. SSO enables a device to maintain its forwarding capability while recovering from a processor failure, minimizing the impact on network traffic. This is accomplished by synchronizing the control plane information between the active and standby processors in the device. In the event of a processor failure, the standby processor takes over the control plane functions without causing any disruption to the forwarding plane.
C ! The Stateful Switchover (SSO) feature works with Nonstop Forwarding (NSF) in Cisco software to minimize the amount of time a network is unavailable to its users following a switchover. The primary objective of SSO is to improve the availability of networks constructed with Cisco routers.
C is correct
"Cisco NSF is supported by the BGP, EIGRP, OSPF, and IS-IS protocols for routing and by Cisco Express Forwarding (CEF) for forwarding"
C is answer
I would say C Graceful Restart and Non-Stop Routing suppress routing changes on peers to Stateful Switch Over (SSO)–enabled devices during processor switchover events of SSO, reducing network instability and downtime. From the official certification guide!
CCNP Enterprise Design ENSLD 300-420 Official Cert - Page 220
Bro this is for Switch fails. This is talking about processor
Cc is correct