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What is the default bridge priority value assigned to Juniper EX Series switches when RSTP is enabled?
2Which command allows an operator to view the designated root bridge identifier and port roles for all active VLANs under RSTP?
3You need to ensure that a core switch retains its position as the root bridge even if a new switch with a manually lowered bridge priority is added to the network. Which feature should you configure on the core switch's ports facing the downstream switches?
4An EX Series switch running RSTP receives BPDUs with superior path cost information from an unauthorized access switch. Which feature should you enable on access-facing ports to prevent these unauthorized BPDUs from altering the spanning tree topology?
5You are troubleshooting a suboptimal spanning tree topology where an EX4300 switch is chosen as the STP Root Bridge despite having a high bridge priority. What command helps verify the current bridge priority and local bridge identifier parameters?
6While examining an RSTP topology, you notice that a designated port has suddenly stopped receiving BPDUs from its upstream neighbor, causing the port to transition into a discarding state to prevent potential loops. Which feature is actively providing this protection?
7An administrator has deployed a new EX Series switch running RSTP and notices that access ports connected to end-user workstations take up to 30 seconds to transition to the forwarding state. Which configuration command should be applied to immediately resolve this delay for access ports?
8What is the role of the Root Port in an RSTP topology?
9An enterprise network runs MSTP. Instance 0 is always reserved for which specific purpose?
10What is the primary function of the RSTP port role known as the 'Backup' port?
11You are configuring MSTP and want to assign VLANs 10 through 50 to MST instance 2. Which configuration hierarchy is correct in Junos OS?
12You suspect that a network loop has formed due to a misconfigured RSTP topology on your EX Series switches. Which command shows real-time topology change notifications and counts on the switch?
13When configuring MSTP, what purpose does the regional configuration digest serve?
14An operator configures RSTP across multiple EX Series switches. A rogue switch running legacy STP is connected to an RSTP switch. How does the RSTP switch handle interaction with the legacy STP switch?
15Which RSTP port role replaces the legacy STP blocking and listening port states to provide rapid convergence?
16You need to modify the bridge priority of an EX Series switch running RSTP to ensure it becomes the root bridge. Which configuration command correctly sets the bridge priority to 4096?
17Which command allows you to verify whether a specific interface on an EX Series switch is operating as an edge port?
18When a topology change occurs in an RSTP network, how are MAC address forwarding table entries affected across the switches?
19An administrator configures link aggregation (ae0) using LACP between two EX Series switches running RSTP. How does RSTP treat the aggregated interface ae0?
20An organization runs MSTP with multiple instances. A packet belonging to a VLAN that is not explicitly mapped to any MST instance is processed in which manner?
21What is the primary purpose of the Hello timer in RSTP?
22An EX Series switch running MSTP receives a BPDU from an upstream switch in a different MST region. How does the receiving switch identify the boundary between the two regions?
23You want to disable spanning tree protocol entirely on a specific access interface (ge-0/0/10.0) of an EX Series switch while keeping RSTP active globally. Which configuration command achieves this?
24Which command is used to display comprehensive spanning tree status, including port roles, states, and priorities across all interfaces on an EX Series switch?
25You are troubleshooting an RSTP topology where a port remains in the discarding state. You suspect a proposal-agreement handshake is failing. Which mechanism is responsible for accelerating this handshake in RSTP?
26An enterprise network uses MSTP. What is the function of the Internal Root in an MST region?
27What action does the 'set protocols rstp max-age <seconds>' command perform on a Juniper switch?
28You notice that an EX Series switch is experiencing frequent topology changes, causing intermittent packet drops across VLANs. Which command helps identify which specific interface is generating the topology changes?
29When configuring MSTP, how is the regional maximum hop count enforced across switches within the same MST region?
30You are configuring an EX Series switch and want to set the forward delay timer to 15 seconds. Which command is used?
31An administrator implements MSTP and wants to configure a maximum hop count of 20 for instance 1. Which configuration command is used in Junos OS?
32An administrator configures root protection on a designated port. If that port subsequently receives a superior BPDU from another switch, what exact state does the port transition into?
33Which TWO port roles are defined in Rapid Spanning Tree Protocol (RSTP) but did not exist in legacy 802.1D STP? (Choose two.)
34Which TWO commands can be used to view spanning tree information on a Juniper EX Series switch? (Choose two.)
35What is the primary benefit of enabling edge port configuration on switch access ports connected to end devices?
36You need to verify the regional configuration name and revision number currently active on an EX Series switch running MSTP. Which operational command should you use?
37Which THREE parameters are included when calculating the MST region configuration digest? (Choose three.)
38Which TWO features help protect an RSTP topology from unauthorized switches or misconfigurations on access ports? (Choose two.)
39Which THREE states are defined in Rapid Spanning Tree Protocol (RSTP)? (Choose three.)
40Which TWO statements are correct regarding the operation of MSTP instance 0 (CIST)? (Choose two.)
41Which TWO actions occur when you configure an interface as an edge port in RSTP? (Choose two.)
42Which THREE parameters can be configured manually to influence root bridge selection in an RSTP network? (Choose three.)
43Which TWO mechanisms are utilized by RSTP to achieve rapid convergence compared to legacy 802.1D STP? (Choose two.)
44Which TWO statements are true regarding loop protection in RSTP? (Choose two.)
45Which THREE parameters must match across all switches for them to successfully form a single MST region? (Choose three.)
46Which TWO conditions will cause an MSTP boundary port to drop BPDUs or recognize a region separation? (Choose two.)
47Which TWO commands are valid Junos configuration hierarchy paths for setting up RSTP? (Choose two.)
48Which TWO parameters are typically configured when tuning RSTP timers on Junos EX Series switches? (Choose two.)
49Which TWO operational commands are useful for troubleshooting MSTP configuration mismatches and instance status on Junos switches? (Choose two.)
50Which THREE actions are performed by an RSTP switch when a topology change is detected? (Choose three.)
51Which THREE statements describe the function of the Designated Port in RSTP? (Choose three.)
52An administrator needs to configure a Juniper EX Series switch to participate in an existing Spanning Tree topology without risking the switch becoming the root bridge. Which command should be used to achieve this?
53You notice that an access switch running RSTP is continually dropping user traffic because a connected end-user device is sending inferior BPDUs that trigger topology changes. Which Juniper feature should you configure on the access ports to protect against this behavior?
54While troubleshooting an RSTP topology on EX Series switches, you notice that a designated port has stopped receiving BPDUs from its upstream neighbor due to a unidirectional link failure. Which feature should you enable to prevent this port from transitioning to a Designated Forwarding state and causing a loop?
55When verifying RSTP operation on a Junos switch, which operational command should you use to view the bridge identifier, root bridge identifier, and local port states?
56An administrator is configuring MSTP on a Junos device and needs to map VLANs 10 through 20 to MST instance 2. Which configuration hierarchy is required to achieve this?
57In an RSTP-enabled network, which port role immediately transitions to the forwarding state upon failure of the designated port on the segment, bypassing the traditional listening and learning states?
58Which TWO parameters are included when a Junos switch calculates the MST configuration digest? (Choose two.)
The Spanning Tree domain covers the key concepts tested in this area of the JNCIS-ENT exam blueprint published by Juniper Networks. Courseiva provides free domain-focused practice, mock exams, missed-question review, and readiness tracking across all JNCIS-ENT domains — no account required.
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