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An administrator needs to view the MAC address learning table on an EX Series switch to verify which switchport a specific server is connected to. Which operational command should be used?
2An administrator needs to create a VLAN named 'voice' with a VLAN ID of 50 on a Junos EX Series switch. Which configuration path achieves this?
3You are configuring Q-in-Q tunneling on an enterprise EX4600 switch. The customer-facing edge port must encapsulate incoming customer frames with an outer VLAN tag of 200. Which port mode should be configured on the customer-facing interface?
4An administrator is configuring a new EX Series switch running Junos OS and needs to assign an access port to VLAN finance. Which configuration hierarchy is used to assign an interface to a specific VLAN?
5You are troubleshooting a connectivity issue between an EX4300 switch access port and an end-host. The port is configured as an access port for VLAN 100, but the host cannot communicate. You run 'show ethernet-switching interface ge-0/0/1' and notice the port status is down/down. Which underlying reason most likely explains this state?
6While reviewing the MAC address table on an EX Series switch using 'show ethernet-switching table', you notice a specific MAC address has a 'Flags' field showing 'L'. What does the 'L' flag indicate?
7An engineer must configure an EX Series switch trunk port to allow all VLANs while explicitly blocking VLAN 50. Which Junos configuration statement accomplishes this behavior?
8On an EX Series switch, you have configured private VLANs (PVLANs) where community VLAN ports need to communicate with a designated promiscuous port, but not with ports in other community VLANs. Which hierarchical configuration is mandatory to bind the primary VLAN and secondary VLANs together?
9An engineer configures Selective QinQ on an EX Series switch. Incoming customer frames tagged with VLAN 10 must be mapped to outer VLAN 500, while frames tagged with VLAN 20 must be mapped to outer VLAN 600. Which configuration component is required to achieve this granular mapping?
10An enterprise network uses private VLANs. A server connected to an isolated port needs to send traffic out of the primary VLAN. Which statement accurately describes how traffic forwarding operates for an isolated port in Junos?
11An administrator wants to verify the configured access VLAN and port mode on interface ge-0/0/2. Which operational command should be used?
12You are configuring a trunk port on an EX Series switch and need to specify that untagged frames received on this port should be placed into VLAN 10. Which command accomplishes this?
13You are configuring multiple VLANs on an EX Series switch and wish to set the aging time for learned MAC addresses to 600 seconds. Where is this parameter configured?
14An administrator needs to delete a MAC address entry from the ethernet-switching table on an EX Series switch due to a stuck entry. Which operational command is used?
15An administrator configures an interface as a trunk port on an EX Series switch, but forgets to specify any VLAN members. By default, how does Junos handle VLAN membership on a newly configured trunk port?
16An enterprise network requires QinQ tunneling where the outer tag EtherType must be explicitly set to 0x88a8 (802.1ad) instead of the standard 0x8100. Where is the custom outer TPID configured on a Junos EX Series switch?
17You need to limit the number of dynamic MAC addresses learned on access interface ge-0/0/5 to a maximum of 10 to prevent MAC flooding attacks. Which configuration accomplishes this?
18An administrator notices that MAC address flapping is occurring between two ports on an EX Series switch due to an unauthorized bridge loop. Which Junos feature can be enabled to automatically detect and action on MAC address movement anomalies?
19An administrator wants to check the total number of active VLANs currently configured on a Junos EX Series switch. Which operational command should be used?
20An engineer is deploying Selective QinQ where customer inner VLAN tags must be preserved while the outer tag is swapped or added based on ingress port rules. Which Junos statement enables tag preservation?
21You are configuring an access port on an EX Series switch and want to ensure that if a MAC address is learned on the port, it persists even after a switch reboot or aging timer expiration. Which configuration attribute achieves this?
22An EX Series switch is configured with a private VLAN primary VLAN 10 and secondary isolated VLAN 20. An administrator wants to verify the active private VLAN port associations and mappings. Which operational command displays this information?
23An administrator needs to remove VLAN 20 from a trunk port that currently allows all VLANs. Which configuration command correctly prunes VLAN 20?
24You are troubleshooting an issue where devices on VLAN 10 cannot communicate across switches because frames are dropping. You suspect a native VLAN mismatch on the interconnecting trunk link. Which operational command helps identify the native VLAN configuration on all trunk ports?
25An administrator configures a new VLAN ID 300 on an EX Series switch but forgets to assign any interfaces to it. What is the operational status of this VLAN?
26You are configuring voice and data VLANs on an EX Series access port. You want the IP phone to process tagged voice traffic for VLAN 50 and pass untagged data traffic from a connected PC into access VLAN 10. Which configuration achieves this?
27An engineer needs to configure a Layer 2 protocol tunneling (L2PT) feature on an EX Series switch trunk port to tunnel BPDU frames from a customer switch across a service provider network. Where is L2PT enabled in Junos?
28An administrator needs to modify the name of an existing VLAN from 'sales' to 'retail' without changing its VLAN ID 40. Which command accomplishes this?
29You are troubleshooting intermittent packet drops on an enterprise switch trunk link. You notice that the MTU configured on the core switch trunk port is 1500, but QinQ double-tagged frames are traversing the link. What is the impact of this MTU configuration?
30An administrator wants to configure MAC-based VLAN assignment on an EX Series switch so that specific client devices are automatically placed into VLAN 20 based on their source MAC address regardless of which port they plug into. Where is MAC-based VLAN assignment configured in Junos?
31An administrator runs 'show vlans' and notices that a particular VLAN has the status 'Active' but no interfaces listed under it. What does this indicate?
32You are configuring a trunk port on an EX Series switch and need to explicitly define the allowed VLAN list as VLANs 10, 20, and 30. Which configuration statement is correct?
33An administrator is troubleshooting a scenario where broadcast traffic from a specific VLAN is flooding a Layer 2 domain and causing high CPU utilization on EX Series switches. Which feature can be configured to limit unknown unicast, broadcast, and multicast (BMC) traffic per VLAN or interface?
34An administrator needs to delete an entire VLAN configuration named 'guest' along with its VLAN ID and associated properties. Which configuration command should be executed?
35You are reviewing the configuration of an EX Series switch and notice that interface ge-0/0/15 is configured with 'interface-mode access' but has no explicit 'vlan members' statement defined. Which VLAN does the interface default to?
36An administrator is configuring VLANs on a Junos EX Series switch. Which TWO tasks must be performed to successfully assign a physical interface as an access port for a newly created VLAN? (Choose two.)
37An engineer is configuring a trunk port on an EX Series switch and needs to ensure that untagged and priority-tagged frames are handled correctly. Which TWO configuration actions are required? (Choose two.)
38An enterprise network design requires implementing private VLANs (PVLANs) on an EX Series switch. Which THREE components or port types are characteristic of a private VLAN architecture? (Choose three.)
39An administrator wants to examine Layer 2 switching status and MAC learning tables on an EX Series switch. Which TWO operational commands can be used to gather this information? (Choose two.)
40You are configuring Q-in-Q tunneling on an enterprise network using EX Series switches. Which THREE configuration elements are essential for implementing Q-in-Q successfully? (Choose three.)
41An engineer is configuring MAC security features on an EX Series switch access port to protect against unauthorized devices. Which THREE features or parameters can be configured under the interface secure-access-port options? (Choose three.)
42An administrator needs to verify the VLAN configuration and port mappings on a Junos EX Series switch. Which TWO operational commands provide this information? (Choose two.)
43You are troubleshooting a Layer 2 connectivity problem where a trunk port is dropping tagged traffic for VLAN 50. Which TWO configuration checks should be performed? (Choose two.)
44An administrator wants to remove an interface from an access VLAN and clear its configuration. Which TWO configuration commands are required to clean up the interface? (Choose two.)
45An administrator is configuring Selective QinQ on an EX Series switch using VLAN translation. Which THREE components are required to successfully rewrite inner and outer VLAN tags? (Choose three.)
46An administrator needs to configure two access ports on an EX Series switch for VLAN 100 named 'engineering'. Which TWO configuration commands are required? (Choose two.)
47An engineer is deploying Private VLANs on an EX Series switch and needs to verify proper operational status and traffic isolation. Which THREE tasks or verification checks should be performed? (Choose three.)
48You are troubleshooting a MAC address flapping issue on an EX Series switch. Which TWO operational commands help diagnose the source and frequency of MAC moves? (Choose two.)
49An engineer is configuring a trunk port on an EX Series switch and needs to manage untagged traffic, allowed VLANs, and native VLAN tagging behavior. Which THREE configurations are valid in Junos for a trunk interface? (Choose three.)
50An administrator is configuring a new Juniper EX Series switch and needs to configure an access port for a VoIP phone and a connected PC. Which Juniper feature should be used to support both the voice and data VLAN on the same physical port?
51A network engineer has configured a trunk port between an EX4300 switch and a third-party switch. The native VLAN traffic is dropping between the switches. Upon troubleshooting, the engineer discovers that the Juniper switch is tagging native VLAN egress traffic, while the peer device expects untagged traffic. Which configuration statement corrects this behavior while preserving trunking?
52You are configuring Q-in-Q tunneling (VLAN stacking) on an EX Series switch where customer traffic with VLANs 10 through 20 needs to be encapsulated into a service provider VLAN 100. Which configuration correctly applies the provider VLAN tag to incoming customer VLANs on a trunk interface?
53An administrator needs to restrict MAC learning on a specific access port (ge-0/0/5) on an EX Series switch to a maximum of 2 learned MAC addresses to prevent MAC flooding attacks. Where is this limit configured in Junos?
54An operator executes the command 'show bridge mac-table' on an EX Series switch running Junos OS. Which information is displayed in the output of this command?
55An administrator wants to prevent unauthorized switches from being connected to user access ports on an EX Series switch. Which feature should be implemented to drop BPDUs received on access ports while keeping the port active for end-user devices?
56Which TWO configuration statements are required when configuring a trunk port on an EX Series switch to allow specific VLANs while blocking others? (Choose two.)
57Which THREE parameters are typically verified when troubleshooting a missing MAC address entry in the bridge table of a Juniper switch? (Choose three.)
58When configuring Private VLANs (PVLANs) on Juniper EX Series switches, which TWO types of ports are defined within the architecture? (Choose two.)
The Layer 2 Switching And VLANs 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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