JNCIP-ENT · domain
IP Telephony Features
Practise Juniper Networks Enterprise Routing and Switching, Professional (JNCIP-ENT, JN0-650) (JNCIP-ENT) IP Telephony Features practice questions — original exam-style scenarios with answer choices, explanations, and analysis of common mistakes.
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What to know about IP Telephony Features
IP Telephony Features questions test whether you can apply the concept in context, not just recognise a definition.
How the topic appears in realistic exam-style scenarios.
Which detail in the question changes the correct answer.
How to eliminate plausible but wrong options.
How to connect the question back to the wider exam objective.
Watch out for
Common IP Telephony Features exam traps
- ▸Answering from memory before reading the full scenario.
- ▸Missing a constraint such as cost, availability, security, scope or command context.
- ▸Choosing a broad answer when the question asks for the most specific fix.
- ▸Ignoring why the wrong options are tempting.
Question index
All IP Telephony Features questions (45)
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Which THREE statements are true regarding voice VLAN technologies and implementation on Junos EX Series switches? (Choose three.)
Medium2Which command displays the global status, TLV counters, and operational state of LLDP on an EX Series switch?
Easy3An administrator implements LLDP-MED on an EX Series switch network. To prevent unauthorized devices from masquerading as IP phones and requesting voice VLAN access, which feature should be combined with LLDP-MED?
Hard4When configuring voice VLANs and PoE on an EX Series switch, which THREE benefits are achieved by implementing LLDP-MED alongside standard PoE? (Choose three.)
Medium5You are reviewing syslog messages on an EX Series switch and see frequent entries indicating PoE power budgeting warnings. You want to configure a custom trap/syslog threshold so that warnings trigger when the total power consumption exceeds 85% of the total available PoE budget. How is this configured?
Hard6An administrator notices that an EX4300 switch is supplying power using LLDP-MED power negotiation, but the IP phone is drawing more power than the initial hardware class allows. Where would you check the advertised LLDP-MED TLV power value received from the phone?
Hard7Which command allows you to verify the real-time PoE power consumption, allocated wattage, and operational status of all interfaces on an EX Series switch?
Easy8An EX3400 switch experiences a total PoE power budget exhaustion after multiple high-power IP phones and security cameras are plugged in. You want to ensure that if a power deficit occurs, the switch immediately cuts power to lower-priority ports while maintaining power to executive phones on specific ports. How should you configure this?
Hard9You are troubleshooting an IP phone that is failing to discover its voice VLAN via LLDP-MED on an EX4600 switch. You issue the show lldp interface command and see that LLDP is transmitting properly, but the phone reports no voice VLAN TLV received. What is the most likely cause of this issue?
Hard10You are configuring a voice VLAN on an EX Series switch access port where an IP phone is connected in series with a PC. Which configuration is required on the switch interface to handle both tagged voice traffic and untagged data traffic?
Medium11A network administrator needs to verify the PoE status, power draw, and allocated class for all connected IP phones across all interfaces on an EX2300 switch. Which operational command should be used?
Easy12An administrator configures PoE management mode on an EX4300 switch to 'consumption'. An IP phone connects, but before booting up completely, the switch denies power. Upon investigation, you find that the switch's static power reservation table is maxed out. What is the reason for this behavior in consumption mode?
Hard13You are configuring an EX Series switch to support IP phones that require both data and voice VLAN segregation on a single access port. You implement an access port configured with a voice VLAN. Which underlying Junos mechanism allows the switch to process untagged data traffic into the native/access VLAN and tagged voice traffic into the voice VLAN simultaneously?
Hard14Which LLDP TLV (Type-Length-Value) is mandatory for LLDP-MED operation and is used to distinguish media endpoint devices from standard network switches and routers?
Easy15An EX4300 switch running Junos OS supports multiple PoE power management options. Which THREE PoE management modes or settings are valid in Junos configuration? (Choose three.)
Hard16An administrator is configuring LLDP-MED on an EX Series switch for a new deployment of IP phones. Which TWO configuration steps are required to properly advertise network policies to these endpoints? (Choose two.)
Medium17You are configuring Power over Ethernet (PoE) on an EX4300 switch to power an IP phone requiring 15.4W (802.3af). By default, the switch allocates power based on dynamic classification. However, the IP phone frequently reboots under heavy traffic load. Which command should you configure on the switch interface to ensure the phone receives a guaranteed dedicated power budget?
Medium18What does the LLDP-MED acronym stand for in the context of enterprise networking and IP telephony?
Easy19You want to configure LLDP-MED to advertise a specific voice VLAN (VLAN ID 200) with a DSCP value of 46 to all connected IP phones across all switch ports. Which configuration hierarchy is used to define this global network policy in Junos OS?
Medium20You need to configure an LLDP-MED network policy for voice traffic on an EX switch, ensuring that the DSCP value is set to 46 and the VLAN ID is set to 150. Which configuration achieves this?
Medium21Which THREE requirements must be met for an IP phone to successfully discover and use a voice VLAN configured via LLDP-MED on an EX Series switch? (Choose three)
Hard22When deploying IP phones that utilize a voice VLAN on EX Series access ports, which THREE characteristics or configurations typically apply to this design? (Choose three.)
Medium23An administrator needs to enable LLDP globally on an EX Series switch running Junos OS to support IP phones. Which command accomplishes this task?
Easy24An administrator needs to configure PoE power management on an EX3400 switch to prioritize port ge-0/0/0 for a critical emergency IP phone. Which statement correctly describes the default PoE priority behavior on Junos EX switches if no explicit priority is configured?
Easy25You are troubleshooting a power budget shortfall on an EX4300 switch where multiple PoE devices are failing to power up. Which TWO actions can you take to resolve or mitigate this power deficit? (Choose two.)
Hard26Which Junos command displays the LLDP neighbor information specifically for a single interface, such as ge-0/0/1?
Easy27You are configuring an EX3400 switch to support IP phones that require power redundancy. Which PoE management feature allows the switch to allocate power based on available PSU capacity while reserving a safety margin?
Medium28Which THREE parameters are typically included in an LLDP-MED network policy TLV for voice application? (Choose three.)
Medium29When configuring Power over Ethernet (PoE) on an EX Series switch, which THREE parameters can be explicitly managed or configured per interface? (Choose three)
Medium30An EX4300 switch is experiencing a PoE budget shortage, causing newly connected IP phones to be denied power. You need to change the PoE power management mode from the default to dynamic consumption-based allocation rather than static class-based allocation. Which command achieves this?
Medium31Which THREE statements describe the behavior of LLDP-MED capability on Junos EX Series switches? (Choose three.)
Medium32You notice that an EX4300 switch power budget calculation is set to use 'class-based' allocation. What does this mean regarding how power is reserved for connected IP phones?
Medium33An administrator wants to verify LLDP and LLDP-MED operation on an EX Series switch. Which THREE operational commands provide relevant diagnostic information? (Choose three.)
Hard34Which TWO actions occur by default on a Junos EX Series switch port when an IP phone successfully negotiates its voice VLAN using LLDP-MED? (Choose two)
Hard35You are configuring voice VLANs on an EX2300 switch. You want to ensure that untagged frames entering the interface are placed into the data VLAN, while frames generated by the attached IP phone are tagged with VLAN 50. Which CLI configuration snippet correctly achieves this?
Medium36You are deploying a new IP telephony network on an EX4300 switch. The voice VLAN must be automatically communicated to connected IP phones using LLDP-MED. Which configuration parameter under system services lldp med fast-start-repeat-count must you configure to ensure rapid initial device discovery?
Medium37You are troubleshooting voice quality issues on an IP phone connected to an EX Series switch. You suspect that the switch is not trusting the DSCP markings (DSCP 46) sent by the IP phone. Which Junos class-of-service (CoS) configuration ensures that incoming voice traffic DSCP bits are trusted at the ingress interface?
Medium38An IP phone connected to an EX4300 switch is assigned to voice VLAN 50 via LLDP-MED. However, when a PC is plugged into the IP phone's pass-through port, the PC cannot obtain an IP address via DHCP. The switch port is configured with interface-mode access and a native VLAN for data. What is the most likely root cause?
Medium39An enterprise network uses IP phones that require LLDP-MED to receive voice VLAN information. However, security policy dictates that LLDP should be disabled on all user-facing access ports that do not have IP phones. Which configuration statement disables LLDP on a per-interface basis?
Hard40An IP phone connected to an EX4600 switch fails to power up. You run show poe interface ge-0/0/1 and find the status displays 'Hardware error'. What is the most appropriate troubleshooting step?
Hard41Which THREE conditions must be met for an EX Series switch to successfully supply PoE power to an attached IP phone? (Choose three.)
Hard42You are troubleshooting an IP phone that is failing to learn its assigned voice VLAN via LLDP-MED from an EX4600 switch. You run show lldp interface ge-0/0/5 and verify LLDP is active. However, the phone's voice VLAN ID TLV is missing from the neighbor information. Which configuration command under the interface must be verified to ensure voice VLAN advertisements are properly transmitted?
Hard43Which command is used to view LLDP-MED specific neighbor details, including device type, capabilities, and network policies on an EX Series switch?
Easy44An administrator notices that LLDP neighbors are failing to populate on an EX Series switch interface. Which THREE troubleshooting steps should be performed? (Choose three.)
Hard45What is the default behavior of an EX Series switch when an LLDP-MED capable IP phone connects and requests a network policy for voice VLAN?
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Frequently asked questions
- What does the IP Telephony Features domain cover on the JNCIP-ENT exam?
- IP Telephony Features questions test whether you can apply the concept in context, not just recognise a definition.
- How many questions are in this domain?
- This page lists all 45 IP Telephony Features questions in the JNCIP-ENT question bank. The actual exam draws from this domain proportionally to its weighting in the official exam blueprint.
- What is the best way to practise this domain?
- Start with a short focused session (10 questions) to identify gaps, then work through explanations. Repeat with a longer session once the weak areas feel solid.
- Can I practise only IP Telephony Features questions?
- Yes — the session launcher on this page filters questions to this domain only. Choose any session length for inline explanations and scoring.