The exhibit displays the default-switch.evpn.0 routing table, which is used on Juniper leaf devices to store EVPN Type 2 (MAC/IP) routes.
Route Distinguisher (Option C): In EVPN, the Route Distinguisher (RD) is an 8-byte prefix added to a route to make it unique within the BGP control plane. The RD format in the exhibit is < IP-Address > : < Identifier
> .
For example, the prefix 2:192.168.100.1:1::5010::... indicates an EVPN Type 2 route (2:) where
192.168.100.1:1 is the Route Distinguisher.
This RD identifies the specific routing instance on the originating VTEP that advertised the MAC/IP address.
Option A is incorrect: The RD 192.168.100.2:1 does not necessarily mean the host device has that IP; it means the originating switch has that router ID/IP used for its RD.
Option B is incorrect: While the RD often incorporates the router ID, the RD itself is the full string (e.g.,
192.168.100.1:1), which is distinct from the raw Router ID used in the BGP summary.
Option D is incorrect: Looking at the entries for 10.1.1.1 and 10.1.2.3, they are associated with different identifiers in the RD strings (5010 and 5020 respectively), which typically map to different VNIs or bridge domains.

VSTP (VLAN Spanning Tree Protocol) is Juniper ' s implementation that provides a separate spanning tree instance for each VLAN, ensuring compatibility with Cisco ' s PVST+. However, it has significant scaling limitations:
Instance Limits: On many Juniper EX and QFX series switches, VSTP is restricted to a maximum of 253 or
510 VLAN instances depending on the software version (ELS vs. non-ELS). In your scenario, having 450 VLANs exceeds the standard 253-instance limit found on many platforms.
The Solution (Option B): When the number of VLANs exceeds the VSTP capacity, the recommended best practice is to enable RSTP (Rapid Spanning Tree Protocol). Unlike VSTP, RSTP runs a single spanning tree instance for the entire switch, regardless of how many VLANs are configured. This ensures that all 450 VLANs are protected from loops without hitting the hardware ' s instance-count limit.
Other Options: Option A (force-version) only affects the BPDU format for compatibility but doesn ' t solve the instance limit. Option C and Option D are parameter tuning actions that do not address the architectural limitation of the number of running instances.

Junos OS 24.4 on EX Series switches provides robust support for LLDP (Link Layer Discovery Protocol) and its extension,LLDP-MED(Media Endpoint Discovery).
* LLDP-MED Power Negotiation:This feature allows a switch (Power Sourcing Equipment or PSE) and a connected device (Powered Device or PD), such as an IP phone or access point, to negotiate power requirements beyond the standard IEEE 802.3af/at classes. The switch candynamically allocate the exact amount of power the device needs (in 0.1W increments), which optimizes the power budget of the switch.
* LLDP Scope:LLDP is a Link Layer protocol (Layer 2), but it is not restricted to Layer 2 interfaces; it can also operate onLayer 3 interfacesto advertise system identity and capabilities. This makesOption A incorrect.
* Link-Local Protocol:LLDP frames use a specific multicast MAC address (01:80:c2:00:00:0e) that is not floodedor forwarded by switches. They are strictly link-local between two directly connected neighbors. This makesOption Bincorrect.
* Endpoint Focus:LLDP-MED is specifically designed forMedia Endpoint Devices(like VoIP phones), providing TLVs for network policy (VLAN/QoS), location identification, and inventory management.
Standard LLDP is used for discovering network connectivity devices. This makesOption Dincorrect.

To simplify VLAN management and automate the creation and pruning of VLANs across a network, Juniper utilizes theMultiple 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 ontrunk interfacesbetween 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 Bare incorrect because GVRP is legacy and no longer the recommended protocol for modern Junos deployments.Option Dis 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 Junos OS, the supplicant-mode configuration under protocols dot1x determines how the switch handles multiple MAC addresses on a single physical port. According to the exhibit, the current mode is set to Single, and the Number of connected supplicants is 2. This indicates that the port is currently allowing multiple devices, which contradicts the goal of limiting access to only one device at a time.
Here is the breakdown of why Option C is the correct solution based on Juniper's standard behavior:
Supplicant Mode: Single (Current State): In this mode, the first device to authenticate opens the port for all subsequent devices. As long as the first device remains authenticated, other devices can send traffic through the port without individual authentication. This is why the exhibit shows 2 connected supplicants despite the mode being " Single. " Supplicant Mode: Single-Secure (The Solution): This mode strictly limits the port to only one MAC address.
Once a device successfully authenticates via 802.1X, the switch drops any traffic coming from any other MAC address on that port. If the authenticated device logs off or the session times out, the port becomes available for a new device, but never more than one simultaneously. * Supplicant Mode: Multiple (Option B):
This mode allows multiple supplicants to authenticate individually. Each MAC address must go through its own authentication process. This would allow more than one device, which is the opposite of the user ' s requirement.
MAC RADIUS Restrict (Option A): This feature is used to force MAC-based authentication and does not inherently limit the number of devices to one in the same way that changing the supplicant mode does.
Maximum EAPOL requests (Option D): This parameter defines how many times the switch will send an EAP- Request/Identity frame to a supplicant before giving up. Changing this to 1 does not restrict the number of devices allowed on the port; it only changes the retry logic for a single authentication attempt.
Configuration Example for Junos OS 24.4: To implement this change, you would use the following command: set protocols dot1x edit interface ge-0/0/10.0 supplicant-mode single-secure