R0 is a Juniper Networks MX router with dual Routing Engines. You must load new software on R0 while ensuring no control plane disruption and minimal data loss.
Which three features meet the requirement? (Choose three.)
Click on the arrows to vote for the correct answer
A. B. C. D. E.BCD
The question is asking for three features that can be used to load new software on a Juniper Networks MX router with dual Routing Engines while ensuring no control plane disruption and minimal data loss. Here are detailed explanations for each of the options provided:
A. Graceful restart: Graceful restart is a feature that allows routing protocols to continue forwarding packets during a control plane disruption. When a control plane disruption occurs, the router does not immediately remove the affected routing information. Instead, it continues to forward packets using the last known good information until the control plane is restored. This feature can help to reduce the amount of time that a network is unavailable and therefore can help to minimize data loss.
B. NSR (Non-Stop Routing): NSR is a feature that enables a routing engine to maintain its forwarding state during a switchover. When a switchover occurs, the new routing engine takes over the forwarding state from the previous one without disrupting traffic. NSR helps to reduce the time required for a switchover and can help to minimize data loss.
C. Graceful Routing-Engine Switchover (GRES): GRES is a feature that enables a router to perform a switchover from one routing engine to another without disrupting traffic. When a switchover occurs, the new routing engine takes over the forwarding state from the previous one without disrupting traffic. GRES helps to reduce the time required for a switchover and can help to minimize data loss.
D. Unified ISSU (In-Service Software Upgrade): Unified ISSU is a feature that enables a router to upgrade its software without disrupting traffic. The upgrade process is performed in two phases, first upgrading the backup Routing Engine and then the primary Routing Engine. During the upgrade process, the router maintains its forwarding state, and there is no control plane disruption or data loss. This feature is typically used when upgrading to a new software version that is not compatible with the previous version.
E. BFD (Bidirectional Forwarding Detection): BFD is a protocol that provides rapid detection of forwarding path failures. When a forwarding path fails, BFD can quickly detect the failure and notify the routing protocol. This can help to minimize data loss by allowing the routing protocol to reroute traffic around the failed path.
Based on the requirement to load new software on the MX router with dual Routing Engines while ensuring no control plane disruption and minimal data loss, the three features that meet this requirement are: