High availability is a key design consideration in the enterprise campus network. In a fully
redundant topology, which is likely to provide faster IGP convergence during a failure?
A.
redundant supervisors
B.
redundant supervisors with Cisco Nonstop Forwarding (NSF) and Stateful Switchover (SSO)
C.
single supervisors with tuned IGP timers
D.
single supervisors
Explanation:
In a fully redundant topology with tuned IGP timers, adding redundant supervisors with Cisco
nonstop forwarding (NSF) and stateful switchover (SSO) may cause longer convergence times
than single supervisors with tuned IGP timers. NSF attempts to maintain the flow of traffic through
a router that has experienced a failure. NSF with SSO is designed to maintain a link-up Layer 3 up
state during a routing convergence event. However, because an interaction occurs between the
IGP timers and the NSF timers, the tuned IGP timers can cause NSF-aware neighbors to reset the
neighbor relationships.