When implementing high-availability stateful switchover BGP routing, in which situation would
Cisco NSR be required?
A.
On the PE routers connecting to the CE routers which are not NSF aware or are not NSF
capable
B.
On the PE routers connecting to the CE routers which support graceful restart
C.
On the PE routers connecting to the CE routers which are incapable of performing stateful
switchover operations because the CE routers are only NSF aware but not NSF capable
D.
On the PE routers connecting to the CE routers which are incapable of performing stateful
switchover operations because the CE routers are only NSF capable but not NSF aware
E.
On the service provider core P routers which are also NSF aware
F.
On the service provider core P routers which are also NSF capable
When Non Stop Routing is used, peer networking devices have no knowledge of any event on the switching over router.
Non Stop Routing uses more system resources due to the information transfer to the standby processor. Standards are not necessary in the case of Non Stop Routing, as the solution does not require any additional communication with protocol peers. NSR is desirable in cases where the routing protocol peer doesn’t support the RFCs necessary to support Graceful Restart
http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/high-availability/solution_overview_c22-487228.html