Ethernet Switching And Spanning Tree

You are configuring VSTP (VLAN Spanning Tree Protocol) on Juniper EX switches to interoperate with legacy third-party switches running PVST+. Which operational command allows you to verify the VSTP bridge identifier and root bridge status per VLAN?

When configuring advanced VLAN mapping on a Juniper MX Series router using flexible VLAN tagging, which term describes the action of replacing an incoming inner VLAN tag with a new tag before forwarding into the provider core?

You need to design a scalable Layer 2 architecture across multiple data center buildings using Juniper switches, avoiding single points of failure while preventing bridging loops. Which scaling mechanism allows Active-Active multihoming without running Spanning Tree Protocol across the core?

You are troubleshooting a Q-in-Q tunneling implementation on an MX Series router where customer VLAN tags are being stripped instead of preserved across the service provider core. Under which configuration hierarchy should the 'vlan-tagging' and 'pop-pop' or 'push' actions be applied on the interface?

An enterprise network engineer needs to configure a trunk port on a Juniper EX Series switch running Junos OS to allow multiple VLANs while explicitly blocking VLAN 99. Which configuration statement under 'interfaces ge-0/0/1 unit 0 family ethernet-switching' correctly achieves this?

You are configuring Q-in-Q tunneling on an MX Series router where customer frames arrive with VLAN tag 100, and you need to encapsulate them with a service provider outer VLAN tag 3000 using 'vlan-map'. Where is the VLAN map applied?

You are configuring private VLANs (PVLANs) on a Juniper EX switch to isolate customer ports from one another while sharing a common gateway. Which VLAN type is configured to allow communication only with promiscuous ports?

An administrator needs to enable BPDU protection on edge access ports in a VSTP environment to prevent loops caused by unauthorized switches. Which command under 'protocols vstp' accomplishes this globally or per-interface?

An enterprise network runs MSTP across an EX Series core. An administrator wants to ensure that a specific core port never becomes the root port for any MSTI, protecting the upstream core path. Which command achieves this?

You are configuring MAC limiting on an EX Series switch interface to restrict the maximum number of learned MAC addresses to 10. What happens when the 11th unique MAC address attempts to communicate through the interface?

In a Juniper Virtual Chassis scaling deployment comprising 10 EX4600 switches, how are control and management planes structured across member switches to maintain high availability and failover resilience?

An engineer is troubleshooting a large-scale enterprise network with multiple MSTP regions connected by a legacy RSTP region. How do boundary switches running MSTP interact with RSTP switches on shared segments?

You want to configure voice VLAN functionality on a Juniper EX switch so that IP phones automatically place voice traffic into VLAN 50 while passing PC data through unchanged. Which feature should you configure?

You are configuring selective Q-in-Q stacking on an MX Series router. Unlike standard Q-in-Q where all customer VLANs are encapsulated into a single provider VLAN, selective Q-in-Q allows you to map specific customer VLAN ranges to different provider VLANs. Which configuration element enables this granularity?

An enterprise network operates VSTP across 150 VLANs. The network engineering team notices high CPU utilization on the Routing Engine due to VSTP BPDU processing. Which Junos command or feature can mitigate this control-plane load while keeping VSTP operational?

An enterprise network engineer is designing a redundant Layer 2 topology with MSTP across Juniper EX switches. Two switches have identical bridge priorities and MAC addresses that result in a tie for regional root. How does MSTP deterministically break the tie to select the regional root bridge?

You are troubleshooting MAC address learning on an EX Series switch and want to display dynamic MAC entries learned specifically on interface ge-0/0/5. Which operational command should you use?

You are configuring Ethernet switching on an EX4300 switch and need to implement storm control to prevent broadcast, multicast, and unknown unicast traffic from overwhelming access links. Where is storm-control applied in the Junos configuration hierarchy?

An enterprise network uses Q-in-Q tunneling over an MX Series provider network. Customer BPDUs must pass transparently across the provider core without being processed by the provider's own VSTP/MSTP instances. Which feature must be enabled on the provider switch access ports to achieve this?

Which TWO operational commands are valid for troubleshooting VSTP on Juniper EX switches? (Choose two)

An administrator needs to verify the operational state of an MSTP instance named 'MSTI-1' on an EX Series switch, including its designated root and regional parameters. Which operational command should be executed?

You are configuring MACsec (Media Access Control Security) on an EX Series switch interface to secure Layer 2 links between two enterprise buildings. Which requirement is mandatory for MACsec to establish a secure session successfully between the two switches?

In a Juniper Q-in-Q deployment, customer frames are received with an EtherType of 0x8100 (IEEE 802.1Q). The service provider network uses a custom provider EtherType of 0x9100 for outer tags. Where and how is this custom EtherType configured on an MX Series router?

Which THREE features or protocols are used in Juniper enterprise switching environments to prevent Layer 2 bridging loops while avoiding traditional Spanning Tree blocking ports? (Choose three)

Which TWO actions can be triggered when a MAC address limit is exceeded on a Juniper switch interface configured with MAC limiting? (Choose two)

When configuring advanced Q-in-Q tunneling on Juniper MX Series routers, which THREE encapsulation or tagging parameters must be correctly aligned between the customer edge and provider edge interfaces? (Choose three)

Which TWO configuration statements are required when setting up an MSTP region on a Juniper EX Series switch? (Choose two)

Which TWO parameters are part of the standard MSTP configuration digest computed across switches in an MST region? (Choose two)

Which TWO security features can be configured on Juniper EX switches to prevent DHCP spoofing and ARP poisoning attacks on Layer 2 access ports? (Choose two)

Which THREE mechanisms are provided by Juniper switches running MSTP to protect against bridging loops caused by unidirectional link failures or misbehaving switches? (Choose three)

Which TWO statements describe the behavior of VSTP (VLAN Spanning Tree Protocol) on Juniper EX Series switches? (Choose two)

When designing a high-scale enterprise campus network using Juniper EX Series switches, which THREE best practices should be followed for Spanning Tree Protocol design? (Choose three)

An engineer is configuring QinQ (802.1ad) tunneling on a Juniper EX Series switch to transport customer VLANs across a service provider core. The customer-facing access port receives tagged frames with outer VLAN ID 100 and inner VLAN ID 200. Which configuration statement correctly defines the interface encapsulation and VLAN mapping?

An enterprise network running VSTP (VLAN Spanning Tree Protocol) across Juniper EX Series switches experiences unexpected loops because a newly added switch does not participate in VSTP for VLAN 50. Upon investigation, you discover the VSTP BPDU multicast destination MAC address is being dropped by a third-party non-Juniper intermediate switch. What is the standard VSTP MAC address used for BPDU transmission?

An administrator wants to configure MSTP on Juniper switches and needs to assign VLANs 10 through 50 to MST Instance 2. Which configuration command hierarchy is correct in Junos?

An engineer is configuring a QinQ tunnel where the service provider bridge needs to transparently carry customer control traffic (like STP BPDUs) through the core without processing them. What feature must be enabled on the provider edge access ports?

You are troubleshooting a switching loop issue in an enterprise core utilizing MSTP. You run 'show mstp interface' and notice that a specific port is stuck in the discarding state for MSTI 1. Which command should you run to verify if root guard has been triggered on this port?

An engineer is deploying VSTP on a Juniper EX Series network. Which THREE characteristics or limitations of VSTP should be considered during the design phase? (Choose three)

When designing advanced enterprise campus VLAN architectures with Juniper EX Series switches, which TWO considerations are critical for large-scale Layer 2 domains? (Choose two)

When configuring advanced Layer 2 tunneling (Q-in-Q) on Juniper EX Series switches, which THREE statements are correct regarding VLAN stacking behavior and limitations? (Choose three)