An ISP has hundreds of routers that run IS-IS on its network.
The ISP is currently redesigning the network, to improve performance and convergence.
Which two IS-IS features meet the ISP requirements when changes happen on the network? (Choose two.)
IS-IS (Intermediate System to Intermediate System) is a link-state routing protocol used in large service provider networks. It is used to exchange information about network topology and build the shortest path tree to all destinations. To improve performance and convergence, there are several IS-IS features that can be used in network redesign. Two of these features are:
Bidirectional Forwarding Detection (BFD): BFD is a mechanism that allows rapid detection of link failures between routers. It is a lightweight protocol that operates independently of the routing protocol, providing sub-second detection of faults. When a failure is detected, IS-IS can quickly recalculate the shortest path tree and reroute traffic around the failed link, reducing downtime and improving network convergence.
Tuning of SPF PRC and LSP generation exponential backoff timers: The SPF (Shortest Path First) algorithm is used by IS-IS to calculate the shortest path tree. When network topology changes occur, IS-IS recalculates the shortest path tree using the SPF algorithm. The PRC (Partial Route Calculation) timer controls the frequency at which IS-IS recalculates the shortest path tree after a change. The LSP (Link State Packet) generation exponential backoff timer controls the frequency at which routers flood their LSPs after a change. By tuning these timers, the network can quickly adapt to changes in topology and converge more quickly.
IP Event Dampening, IS-IS Fast Flooding of LSPs, and Tuning of IS-IS Hello Parameters are not directly related to improving network convergence and performance in IS-IS. IP Event Dampening is used to suppress the generation of routing updates in response to network events that cause network instability. IS-IS Fast Flooding of LSPs is used to quickly flood LSPs after a change, but this feature may cause network instability if not used carefully. Tuning of IS-IS Hello Parameters is used to adjust the frequency and timeout values for IS-IS hellos, but this feature does not directly improve network convergence and performance.