Juniper JN0-650 Dumps - Pass Enterprise Routing and Switching, Professional Exam in 2026

In an EVPN-VXLAN environment, different BGP route types serve distinct purposes in building the control plane. The Ethernet Segment Identifier (ESI) is a unique 10-byte identifier used to represent a multi-homed segment.

Type 1: Ethernet Auto-Discovery (A-D) Route (Option A): This route type is essential for multi-homing scenarios. It carries the ESI to support features like fast convergence and aliasing. By advertising an A-D route per Ethernet Segment, a PE tells other routers that it is connected to that specific ESI. It does not carry individual host MAC addresses; instead, it provides a 'mass withdraw' mechanism to quickly update paths if the entire segment goes down.

Type 4: Ethernet Segment Route (Option D): This route is used exclusively for Designated Forwarder (DF) election. It advertises the existence of an ESI and the ES-Import Route Target to all other PE routers. This allows PE routers connected to the same multi-homed segment to discover each other automatically and elect a DF to handle BUM traffic. Like Type 1, it focuses on the segment identity and does not include MAC addresses.

Type 2: MAC/IP Advertisement Route (Option B): This is the primary route used for host reachability. It must include a MAC address (and optionally an IP). While it also includes the ESI to indicate which segment the host is behind, its primary function is MAC advertisement.

Type 3: Inclusive Multicast Ethernet Tag Route (Option C): This route is used for VTEP discovery and building the replication list for BUM traffic. It identifies the VTEP's IP and the VNI, but it does not carry the ESI or MAC addresses.

To simplify VLAN management and automate the creation and pruning of VLANs across a network, Juniper utilizes the Multiple VLAN Registration Protocol (MVRP).

MVRP on Trunk Interfaces (Option C): MVRP is the IEEE 802.1ak standard that replaces the older, proprietary GVRP. It is designed to run on trunk interfaces between switches.

Dynamic Creation: When a VLAN is added to one switch, MVRP advertises its existence to neighboring switches. If those switches need to reach that VLAN, they can dynamically create it in their database.

Pruning: If a switch no longer has any active ports or downstream neighbors interested in a specific VLAN, it stops advertising that VLAN on its trunks. This 'prunes' the VLAN traffic from those links, saving bandwidth.

Incorrect Options: Option A and B are incorrect because GVRP is legacy and no longer the recommended protocol for modern Junos deployments. Option D is incorrect because MVRP is meant for inter-switch trunk links to manage the fabric, not for edge access ports where VLAN membership is usually static.

In an end-to-end CoS (Class of Service) design, there is a clear distinction between classification at the ingress and rewrite rules at the egress.

The Problem: Your edge devices are successfully classifying traffic (assigning packets to internal forwarding classes). However, the core devices---which use BA (Behavior Aggregate) classifiers---are not classifying correctly. BA classifiers look at the bits in the packet header (like DSCP or 802.1p) to determine priority.

The Missing Link (Option C): When a packet leaves the edge device, its internal forwarding class and loss priority must be 'written' back into the packet header so that the next-hop (the core device) can see it. By default, Junos may not preserve or set these bits correctly on egress. You must apply rewrite rules on the edge switches' egress interfaces facing the core. These rules ensure the DSCP values in the headers match the forwarding class determined by the edge's MF classifier, allowing the core's BA classifier to function properly.

Other Options: Option A (policer) handles rate limiting, not classification. Option B is incorrect because core devices often have different hardware or scaling needs than edge switches, and standard BA configuration is preferred over templates in the core. Option D is incorrect because MF classifiers are standard for edge devices where deep packet inspection is needed to identify traffic types.

In Junos OS, the figure-of-merit is an internal numerical value used by the BGP Route Damping mechanism to quantify the stability of a specific BGP route. When a route 'flaps' (becomes unstable), the Junos OS increases this value by assigning a specific penalty based on the type of event that occurred:

The route is withdrawn (Option A): When a BGP neighbor sends a withdrawal message for a prefix, Junos assigns a significant penalty---typically 1,000 by default---to the route's figure-of-merit.

The route is readvertised (Option C): When a previously withdrawn route is announced again by the neighbor, the Junos OS adds another penalty to the figure-of-merit value to track the continued instability.

The route's path attributes changed (Option E): If a route remains reachable but its BGP attributes (such as the AS Path or Community) change, it is considered a flap. Junos assigns a smaller penalty---typically 500 by default---for this attribute change.

As the figure-of-merit accumulates and exceeds a predefined suppress threshold, the route is suppressed and no longer used for forwarding. Over time, the value decreases according to a configured half-life until it falls below a reuse threshold, at which point the route becomes active again. Factors like local preference or the origin (IBGP/EBGP) do not trigger these internal penalty increments for the figure-of-merit.

To secure a Layer 2 network running Multiple VLAN Registration Protocol (MVRP) against unauthorized VLAN propagation from rogue devices, you must control the registration state of the ports.

Forbidden Registration Mode (Option D): This mode is specifically designed to prevent an interface from participating in the MVRP exchange.

When a port is set to forbidden, it will neither register nor declare VLANs (except those statically configured on the interface).

If a rogue device sends MVRP PDUs to this interface, the distribution switch will ignore those PDUs, preventing the rogue device from dynamically creating or learning VLANs through that port.

Registration Hierarchy: In Junos OS 24.4, this is configured at the [edit protocols mvrp interface <interface-name> registration forbidden] level.

Other Modes: normal (default) allows full participation, while restricted ignores joins for VLANs not already statically defined on the switch but still declares its own.