Juniper JN0-650 Exam With Confidence Using Practice Dumps

The exhibit shows a multicast network running PIM Sparse Mode where R2 is configured as a local Rendezvous Point (RP). However, the non-RP routers (like R5) show no learned RP in their show pim rps output. To resolve this using standard protocols for dynamic RP discovery, you must implement a mechanism that automates the distribution of RP information across the PIM domain.

Bootstrap Router (BSR) (Option B): BSR is the industry-standard (RFC 5059) mechanism for dynamically electing an RP and distributing that information throughout a PIM-SM domain.

It uses two roles: Candidate-RPs (C-RPs), which announce their desire to be an RP, and Candidate-BSRs (C-BSRs), which collect these announcements and flood them to all other routers in the network via PIM bootstrap messages.

BSR is a " standard protocol " as it is part of the PIMv2 specification. Once configured on R2 (as C-RP) and potentially R1 or R2 (as C-BSR), all other routers will dynamically learn that R2 is the RP for the specified group ranges.

Auto-RP (Option D): While this also provides dynamic RP discovery, it is a proprietary Cisco protocol. Although Junos supports it for interoperability, the question specifically asks for " standard protocols only, " making BSR the preferred choice.

MSDP (Option A): Multicast Source Discovery Protocol (MSDP) is used to share information about active sources between different PIM domains or for Anycast-RP. It does not handle the initial discovery of an RP within a single domain for standard PIM-SM operations.

Anycast RP (Option C): This is a technique used for RP redundancy and load balancing. While it can use BSR or MSDP for synchronization, it is a design architecture rather than a standalone " standard protocol " for the basic dynamic discovery of an RP in the manner requested here.

Configuration Example for BSR in Junos OS 24.4: To enable this, you would add the following to the RP (R2):

set protocols pim rp bootstrap-discovery

set protocols pim rp candidate-rp 10.222.1.2 group-ranges 224.0.0.0/4

set protocols pim rp candidate-bsr 10.222.1.2

When a peer incorrectly floods your router with an excessive number of routes, it can exhaust system resources and crash the routing engine.

Prefix-Limit (Option B): The prefix-limit (or accepted-prefix-limit) parameter is the primary defense against such " route leaks " .

You can set a maximum threshold for the number of prefixes allowed from a specific BGP neighbor or group.

When the limit is reached, Junos can be configured to either just log a warning or tear down the BGP session entirely (using the teardown keyword) to protect the router.

This prevents the " hundreds of thousand routes " from ever being fully processed or installed into the main routing table.

Damping (Option A): Damping is used to suppress unstable, " flapping " routes, but it does not limit the total volume of stable routes received.

This scenario describes the standard transition of Class of Service (CoS) metadata from the network edge to the network core.

MF vs. BA Classification: Edge devices use Multifield (MF) classifiers because incoming traffic often lacks markings. MF classification assigns traffic to an internal forwarding class based on multiple fields (IPs, ports, etc.). Core devices use Behavior Aggregate (BA) classifiers because they are faster; they only look at the CoS bits (like DSCP) in the header to determine the forwarding class.

The Problem: Internal forwarding class assignments made by an MF classifier on the edge device do not automatically travel with the packet. If the packet leaves the edge device with its original (potentially zeroed) DSCP bits, the core device ' s BA classifier will not be able to identify the priority.

The Solution (Option A): You must implement rewrite rules on the egress interfaces of the edge devices. A rewrite rule takes the internal forwarding class and loss priority assigned by the MF classifier and " writes " the corresponding DSCP value into the packet header as it exits toward the core. This ensures that the core device sees the correct DSCP marking and can apply the appropriate BA classification.

Incorrect Options: Rewrite rules are strictly an egress function to modify the packet for the next hop. Applying them on ingress (Option B) or core ingress (Option C) does not solve the problem of ensuring the packet header reflects the classification logic used during the internal switching process of the edge device.