CCNA EVPN Questions

Multi-Selectmedium

Which TWO factors can cause an EVPN instance on a Junos device to fail in importing incoming Type-2 MAC/IP routes? (Choose two)

Select 2 answers

A.Configuring an incorrect BGP router ID on the remote peer.

B.Enabling MAC limit suppression on access ports.

C.The EVPN routing instance is missing or has an incorrect instance-type configured.

D.Incorrect loopback MTU settings on the physical underlay interfaces.

E.A mismatch between the import route target on the receiving PE and the export route target on the advertising PE.

AnswersC, E

Without a properly configured EVPN routing instance, the routing table cannot accept EVPN route imports.

Why this answer

Route import failures in EVPN are typically caused by mismatched Route Targets between the advertising and receiving PE, or missing/incorrect EVPN routing instance configurations.

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MCQmedium

An engineer is troubleshooting a newly configured EVPN-VXLAN multi-homed setup where the Designated Forwarder (DF) is constantly toggling between two PE routers. What is the most likely cause of this DF churn?

A.Incorrect MAC mobility sequence numbers.

B.Mismatched Ethernet Segment Identifiers (ESIs) or unstable BGP connectivity between PEs.

C.Exceeding the maximum MAC address table limit.

D.Using VXLAN instead of MPLS data plane encapsulation.

AnswerB

If ESIs match but BGP session stability or Type-4 route advertisements fluctuate, the DF election re-runs continuously, causing churn.

Why this answer

DF churn typically occurs when BGP sessions or reachability between the PE routers flapping, or when the timers (such as wait-for-timer) are misconfigured, causing conflicting DF election states.

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Multi-Selecthard

Which TWO of the following characteristics apply to EVPN Route Type 3 (Inclusive Multicast Ethernet Tag Route)? (Choose two)

Select 2 answers

A.It advertises host IP prefixes for inter-subnet routing.

B.It carries the originating router's IP address and an Ethernet Tag/VNI identifier.

C.It dynamically triggers MAC mobility sequence number increments.

D.It performs Designated Forwarder election on multi-homed links.

E.It is used to establish ingress replication lists for BUM traffic distribution.

AnswersB, E

Type 3 route payloads include the originating router's IP and the Ethernet tag or VNI.

Why this answer

Route Type 3 routes are used to construct the multicast/broadcast distribution tree using ingress replication (head-end replication) by advertising the PE's IP address and Ethernet tag/VNI.

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Multi-Selecthard

Which THREE of the following statements describe the behavior and purpose of EVPN Route Type 5 (IP Prefix Route)? (Choose three)

Select 3 answers

A.It is mandatory for establishing basic Layer 2 bridging across a single VLAN.

B.It is frequently used for inter-subnet routing and integration with MPLS L3VPN backbones.

C.It replaces Ethernet Segment Identifiers on multi-homed ports.

D.It can include a gateway IP address to facilitate IP routing across VTEPs.

E.It allows the advertisement of IP prefixes independently of MAC addresses.

AnswersB, D, E

Type 5 routes bridge EVPN data centers with external IP-VRF / L3VPN networks.

Why this answer

Route Type 5 carries IP prefixes independently of MAC addresses, supports inter-subnet forwarding in IP-VRF or EVPN-VXLAN integrations, and can carry gateway IP information.

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Multi-Selecthard

When designing an EVPN-VXLAN fabric with integrated routing and bridging (IRB), which THREE considerations are critical for proper inter-subnet forwarding across VTEPs? (Choose three)

Select 3 answers

A.Enforcing physical loopback interfaces to run in layer 2 bridging mode.

B.Configuring consistent virtual gateway MAC and IP addresses on all IRB interfaces across leaf VTEPs.

C.Disabling BGP EVPN signaling on all spine nodes to save CPU resources.

D.Mapping each bridge domain to a unique VXLAN Network Identifier (VNI).

E.Advertising host routes or subnet prefixes via EVPN Type-2 or Type-5 routes.

AnswersB, D, E

Anycast gateways require identical virtual MAC and IP settings on every leaf router's IRB interface.

Why this answer

Distributed IRB gateways require consistent anycast gateway MAC and IP configurations across all leaf nodes, correct VNI to bridge domain mappings, and EVPN Type-5 or Type-2 route propagation for host/subnet reachability.

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MCQhard

You are troubleshooting a scenario where an MX Series router running an EVPN-VXLAN instance receives Type-2 routes from a remote PE, but the local data plane fails to install the forwarding entries because of a mismatch in encapsulation types. Where is the encapsulation type for VXLAN defined within a Junos EVPN instance?

A.protocols bgp group <name> family evpn encapsulation vxlan

B.interfaces lo0.0 family vxlan

C.routing-instances <name> instance-type evpn; ... encapsulation vxlan;

D.bridge-domains <name> vni <id> encapsulation mpls

AnswerC

Encapsulation vxlan is configured directly inside the routing instance or switch options block.

Why this answer

In Junos OS, the encapsulation for the routing instance or switch options is defined using the 'encapsulation vxlan' statement under the routing-instance or switch-options hierarchy.

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MCQmedium

An administrator configures EVPN with VXLAN encapsulation and wants to ensure that interfaces assigned to bridge domains drop frames whose source MAC address is not learned or is unauthorized. Which feature should be enabled?

A.MAC security / MAC limit with drop action

B.Ingress replication disabling

C.BGP route filtering

D.EVPN Route Type 4 filtering

AnswerA

MAC limit features with action drop protect bridge domains from MAC flooding and unauthorized source MACs.

Why this answer

Configuring MAC limit or bpdu protection/port security features on access interfaces prevents unauthorized MAC learning, while EVPN sticky MAC features can lock MACs to specific interfaces.

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MCQmedium

An administrator wishes to configure VXLAN data plane encapsulation on an MX Series router with an EVPN instance. Which statement under the routing-instances hierarchy defines the local VTEP source interface?

A.encapsulation-source-interface fxp0.0;

B.vxlan-source-ip lo0.0;

C.tunnel-source loopback 0;

D.vtep-source-interface lo0.0;

AnswerD

The vtep-source-interface command specifies the loopback interface used as the source IP for VXLAN packets.

Why this answer

In Junos OS, the VXLAN source interface is defined using the 'vtep-source-interface' statement under the EVPN routing instance or switch-options hierarchy.

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MCQeasy

Which EVPN route type is responsible for advertising MAC addresses combined with IP addresses (MAC/IP Advertisement Route)?

A.Route Type 3

B.Route Type 2

C.Route Type 4

D.Route Type 1

AnswerB

Route Type 2 advertises MAC and IP bindings.

Why this answer

Route Type 2 is the MAC/IP Advertisement Route, which carries a MAC address and optionally an IP address, facilitating both L2 bridging and L3 host routing.

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MCQhard

You are analyzing BGP EVPN updates and observe an Extended Community attached to a Type-2 route containing a sequence number. What is the primary function of this MAC Mobility Extended Community?

A.It signals the EVPN split-horizon label for BUM traffic.

B.It facilitates loop-free MAC movement tracking by incrementing sequence numbers when a host changes attachment PEs.

C.It determines the Designated Forwarder for multi-homed Ethernet segments.

D.It defines the VXLAN Network Identifier (VNI) mapping for data-plane decapsulation.

AnswerB

MAC mobility sequence numbers ensure that the network correctly updates MAC locations and prevents blackholing during rapid MAC moves.

Why this answer

The MAC Mobility Extended Community carries a sequence number used to resolve MAC moves. If a host moves from one PE to another, the new PE advertises the MAC with an incremented sequence number, causing all other PEs to update their tables to point to the new location.

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Multi-Selecthard

Which TWO of the following statements regarding EVPN Route Type 1 (Ethernet Auto-Discovery Route) are correct? (Choose two)

Select 2 answers

A.Type 1 routes are only used in single-homed network topologies.

B.Type 1 routes are advertised either per-EVI or per-Ethernet Segment (ES).

C.Type 1 routes are exclusively used for mapping IP prefixes to IP-VRFs.

D.Per-EVI Type 1 routes enable multi-homing aliasing so PEs can load balance traffic even before learning a MAC locally.

E.Type 1 routes replace Type 3 routes for handling BUM traffic replication.

AnswersB, D

Type 1 routes have two distinct encodings: per-EVI (for aliasing) and per-ES (for fast convergence/mass withdrawal).

Why this answer

Route Type 1 comes in two variants: per-EVI and per-ES. Per-EVI routes provide aliasing for load-balancing across multi-homed PEs, and per-ES routes facilitate fast convergence during node failures.

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MCQeasy

Which command allows an operator to view the local and remote MAC addresses learned via EVPN control plane and data plane across all bridge domains on an MX Series router?

A.show bridge domain

B.show route table inet.0

C.show evpn database

D.show mpls lsp

AnswerC

This command outputs the complete EVPN MAC/IP database learned across all PEs.

Why this answer

The 'show evpn database' command displays the EVPN routing/MAC table containing MAC addresses learned via BGP EVPN control plane and local data plane learning.

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MCQmedium

An administrator is deploying EVPN multi-homing with all-active mode on an MX Series router. Which configuration element uniquely identifies the provider edge (PE) router's attachment circuit to an Ethernet segment?

A.Route Distinguisher (RD)

B.Ethernet Tag ID

C.Ethernet Segment Identifier (ESI)

D.ESI Label Extended Community

AnswerC

The ESI uniquely identifies the multi-homed segment across the network.

Why this answer

The Ethernet Segment Identifier (ESI) is a 10-octet unique identifier configured under the interface or access link to identify an Ethernet segment for multi-homing.

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MCQhard

You are troubleshooting a suboptimal traffic forwarding issue in an EVPN-VXLAN fabric with multi-homed devices. Traffic destined for a multi-homed server is being sent to only one of the PEs despite all-active mode being configured. Which EVPN route type and mechanism are responsible for enabling load balancing across all available PEs attached to the same Ethernet segment?

A.Route Type 1 (Ethernet Auto-Discovery per EVI)

B.Route Type 2 with MAC mobility extended community

C.Route Type 4 (Ethernet Segment Route)

D.Route Type 3 (Inclusive Multicast)

AnswerA

Type 1 routes per EVI provide the aliasing function required for load balancing traffic across all PEs attached to a multi-homed segment.

Why this answer

Type 1 Ethernet A-D routes per EVI are used for multi-homing aliasing, allowing PEs that do not learn a specific MAC address locally to still load-balance traffic to that MAC across all PEs advertising the ESI via Type 1 routes.

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Multi-Selectmedium

Which TWO statements describe characteristics of EVPN All-Active Multi-Homing compared to Single-Active Multi-Homing? (Choose two)

Select 2 answers

A.All-active multi-homing restricts host MAC learning to only one PE at a time.

B.In all-active mode, only the Designated Forwarder handles unicast traffic from the core.

C.All-active multi-homing requires Spanning Tree Protocol to block redundant links.

D.All-active multi-homing allows multiple PEs attached to the same Ethernet segment to forward traffic simultaneously.

E.All-active multi-homing utilizes EVPN Route Type 1 per-EVI routes to enable load-balancing (aliasing) across PEs.

AnswersD, E

In all-active mode, all attached PEs actively forward traffic for the multi-homed segment.

Why this answer

All-active multi-homing allows multiple PEs connected to the same Ethernet segment to actively forward traffic simultaneously and load-balance unicast traffic using aliasing, unlike single-active where only the DF forwards traffic.

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MCQeasy

Which specific EVPN route type is responsible for carrying IP prefix routes, often used for inter-subnet forwarding in an IP-VRF-to-EVPN integration scenario?

A.Route Type 5

B.Route Type 3

C.Route Type 2

D.Route Type 1

AnswerA

Route Type 5 carries IP prefixes for IP-VRF routing in EVPN.

Why this answer

EVPN Route Type 5 is the IP Prefix Route, which allows the advertisement of IP prefixes (host or subnet routes) independently of MAC addresses, facilitating integrated routing and bridging (IRB) and inter-subnet forwarding.

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MCQmedium

An enterprise network architect is designing an EVPN-VXLAN fabric and wants to ensure that MAC address churn (frequent moving of a MAC between ports) does not destabilize the control plane. Which feature should be enabled in the EVPN instance?

A.MAC limit and MAC mobility sequence numbering

B.Spanning Tree BPDU protection

C.Fast-reroute backup paths

D.BGP route flap damping

AnswerA

MAC mobility uses sequence numbers to track legitimate moves and provides detection to suppress churn.

Why this answer

MAC mobility features, including MAC move detection and sticky MAC or suppression mechanisms, protect the EVPN control plane from frequent MAC moves by incrementing sequence numbers and applying penalties if movement thresholds are exceeded.

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MCQhard

During a maintenance window, an administrator needs to manually force a Designated Forwarder (DF) role change on a multi-homed Ethernet segment for an EVPN instance. Which parameter must be adjusted to influence the DF election algorithm in Junos OS?

A.BGP AS path prepending

B.Route Distinguisher value

C.Router ID of the BGP speaker

D.Ethernet segment preference value

AnswerD

Configuring a higher or lower segment preference value under the ESI configuration explicitly influences the DF election.

Why this answer

Junos OS allows influencing the DF election by adjusting the interface preference or local preference values associated with the Ethernet Segment, altering how the DF election algorithm selects the forwarder.

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MCQhard

You are designing an EVPN network with active-active multi-homing. A host sends traffic to a multi-homed PE. The PE receives the traffic on a designated link. How does EVPN suppress unnecessary flooding across the core for unknown unicast traffic originating from a multi-homed site?

A.By utilizing Spanning Tree Protocol to block redundant ports across the core.

B.By dropping all packets with unknown destination MAC addresses at the ingress leaf.

C.By enforcing ingress replication drop filters on Type 3 routes.

D.By dynamically learning MAC addresses via control-plane Type 2 routes, turning unknown unicast into known unicast.

AnswerD

Control-plane MAC learning via Type 2 routes ensures remote PEs know the MAC location immediately, avoiding data-plane flooding.

Why this answer

EVPN suppresses unknown unicast flooding by performing MAC learning via control-plane advertisement (Type 2 routes) upon first contact, so subsequent traffic is unicast-forwarded rather than flooded.

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MCQmedium

An engineer is verifying MAC learning behavior in an EVPN instance. A remote host's MAC address is learned via BGP Type 2 routes, but when the local host sends traffic to it, the packet drops. The engineer runs 'show route table bgp.evpn.0' and sees the route. What is the most likely reason the packet is dropping in the data plane?

A.The data-plane VNI mapping or tunnel next-hop resolution is incomplete.

B.Type-4 routes have not been exchanged yet.

C.The BGP route target import policy is rejecting the route.

D.The local router's BGP router ID is misconfigured.

AnswerA

Control-plane success does not guarantee data-plane tunnel setup; VNI bindings and IP reachability to the remote VTEP must be valid.

Why this answer

Even if the control plane has learned the EVPN Type 2 route, if the data plane tunnel encapsulation (such as a missing VNI mapping or incomplete VXLAN next-hop resolution) is misconfigured, data plane forwarding will fail.

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Multi-Selectmedium

Which THREE parameters are typically included or evaluated when configuring and verifying BGP EVPN peer sessions on Junos OS devices? (Choose three)

Select 3 answers

A.Route targets (import and export) to control the exchange of EVPN routes between routing instances.

B.RSVP bandwidth reservation for the BGP TCP session.

C.Spanning tree priority configuration for the BGP peering interface.

D.BGP family evpn signaling (or l2vpn evpn) address family activation.

E.Route Distinguisher (RD) to ensure unique route identification per EVPN instance.

AnswersA, D, E

Route targets determine which EVPN routes are imported into or exported from an EVPN routing instance.

Why this answer

BGP EVPN peering requires the BGP neighbor IP/address family configuration, Route Targets for import/export control, and Route Distinguishers for uniqueness within the routing instance.

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MCQeasy

Which EVPN route type is responsible for establishing ingress replication lists for Broadcast, Unknown Unicast, and Multicast (BUM) traffic?

A.Route Type 3

B.Route Type 5

C.Route Type 4

D.Route Type 1

AnswerA

Route Type 3 establishes the inclusive multicast tree/replication list for BUM traffic.

Why this answer

Route Type 3 (Inclusive Multicast Ethernet Tag Route) is used to build the peer list for BUM traffic distribution using ingress replication (head-end replication).

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MCQeasy

Which EVPN route type is known as the Ethernet Segment Route and is advertised by a PE router to signal its connectivity to a multi-homed Ethernet segment?

A.Route Type 2

B.Route Type 3

C.Route Type 1

D.Route Type 4

AnswerD

Route Type 4 is the Ethernet Segment Route used for DF election.

Why this answer

EVPN Route Type 4 is the Ethernet Segment Route, used for discovering other PEs attached to the same Ethernet segment and executing the Designated Forwarder (DF) election.

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Multi-Selecthard

Which THREE actions occur during the EVPN Designated Forwarder (DF) election process on a multi-homed Ethernet segment? (Choose three)

Select 3 answers

A.A Designated Forwarder is elected to forward BUM traffic from the core to the multi-homed site.

B.All participating PEs simultaneously forward BUM traffic to maximize bandwidth utilization.

C.Segment preference values and IP addresses are evaluated to determine the forwarding role deterministically.

D.MAC mobility sequence numbers are reset to zero during the election.

E.PE routers exchange Route Type 4 (Ethernet Segment Routes) to discover peers attached to the same segment.

AnswersA, C, E

The DF is responsible for sending BUM traffic down to the attached customer site.

Why this answer

DF election uses Route Type 4 (Ethernet Segment routes) to exchange reachability, determines the forwarder based on preference and algorithms, and assigns responsibility for BUM traffic forwarding.

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MCQmedium

An engineer is troubleshooting EVPN type 2 routes between two MX Series routers and notices that MAC addresses learned locally are not being advertised to the remote VTEP. Which command should the engineer use to verify that the EVPN instance is actively generating and exporting MAC-VRF routes?

A.show bridge mac-table

B.show bgp summary

C.show route advertising-protocol bgp <neighbor-ip>

D.show evpn database

AnswerC

This command displays the exact routes advertised to a specific BGP neighbor, confirming route generation and export.

Why this answer

The 'show route advertising-protocol bgp' command allows an engineer to verify which routes (including EVPN type 2 MAC/IP routes) are being advertised to a specific BGP peer or peer group for an EVPN routing instance.

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MCQhard

You are configuring a Junos EVPN-VXLAN environment where Type-3 (Inclusive Multicast Ethernet Tag) routes are being exchanged. A remote MX router is failing to establish ingress replication tunnels because it does not import the Type-3 route. Which configuration statement under the routing-instance is missing or misconfigured?

A.no-normalization

B.route-target import

C.multicast-snooping

D.vtep-source-interface lo0.0

AnswerB

Type-3 routes use standard BGP route targets. If the import route target is missing or incorrect, the Type-3 route will not be accepted into the EVPN routing instance's BGP table.

Why this answer

EVPN Type-3 routes carry the Inclusive Multicast Ethernet Tag and rely on route targets for import and export. If the import route-target does not match the advertising router's export route-target, the tunnel endpoints are not dynamically bound.

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MCQeasy

Which Junos configuration hierarchy is used to define an EVPN routing instance of type 'evpn'?

A.bridge-domains <name> evpn

B.protocols evpn

C.routing-instances <name> instance-type evpn

D.interfaces xe-0/0/0 unit 0 family evpn

AnswerC

The correct hierarchy for creating an EVPN instance is under routing-instances with instance-type evpn.

Why this answer

In Junos OS, EVPN instances are defined under 'routing-instances <name> instance-type evpn'.

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Multi-Selectmedium

When troubleshooting EVPN control plane connectivity in Junos OS, which THREE commands provide essential diagnostic information regarding EVPN routing tables and peers? (Choose three)

Select 3 answers

A.show mpls lsp extensive

B.show route table bgp.evpn.0

C.show bgp summary

D.show spanning-tree interface

E.show evpn database

AnswersB, C, E

This displays the master BGP EVPN routing table containing all received EVPN routes.

Why this answer

To troubleshoot EVPN control plane issues, commands like 'show route table bgp.evpn.0', 'show bgp summary', and 'show evpn database' are essential for verifying route tables, neighbor status, and MAC databases.

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MCQhard

You are integrating an EVPN-VXLAN fabric with an existing MPLS L3VPN backbone using a data center gateway. Which route type allows seamless translation and communication of prefix routes between the EVPN instance and the IP-VRF MPLS VPN backbone?

A.Route Type 5

B.Route Type 3

C.Route Type 1

D.Route Type 2

AnswerA

Route Type 5 provides IP prefix routes that map directly to IP-VRF constructs for inter-domain routing.

Why this answer

EVPN Route Type 5 (IP Prefix Route) permits the advertising of IP prefixes that can be easily imported into IP-VRFs, bridging EVPN and classical MPLS L3VPN domains.

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MCQhard

When configuring centralized gateway or distributed gateway routing models in an EVPN-VXLAN environment, how does a distributed gateway using Integrated Routing and Bridging (IRB) interfaces operate regarding default gateway functionality?

A.Routing is disabled on leaf nodes, requiring all packets to be tunneled to spine nodes for L3 lookup.

B.A single designated MX core router handles all inter-subnet routing via centralized IRB interfaces.

C.Hosts must run VRRP between leaf nodes to dynamically elect a single active gateway.

D.All leaf nodes act as default gateways using the same virtual MAC and IP address, terminating traffic locally.

AnswerD

Distributed gateways use an anycast gateway configuration where every leaf responds as the default gateway for local subnets.

Why this answer

In a distributed gateway model, every leaf/VTEP acts as the default gateway for its directly attached subnets, using anycast MAC and IP addresses so hosts can send traffic to their local VTEP regardless of which leaf they connect to.

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Multi-Selectmedium

When configuring EVPN multi-homing in all-active mode, which THREE key components or concepts must be properly established across the PE routers? (Choose three)

Select 3 answers

A.Enabling Spanning Tree Protocol root bridge on all leaf nodes.

B.A Designated Forwarder (DF) election mechanism using Type-4 routes to determine who forwards BUM traffic.

C.A matching Ethernet Segment Identifier (ESI) configured on the attachment circuits of all participating PEs.

D.Split-horizon filtering using ESI labels to prevent BUM traffic loops back to the multi-homed site.

E.Configuring OSPF as the underlay routing protocol for EVPN signaling.

AnswersB, C, D

Type-4 routes drive DF election so only one PE forwards BUM traffic to the multi-homed segment at a given time.

Why this answer

EVPN all-active multi-homing requires a consistent Ethernet Segment Identifier (ESI) across participating PEs, an active Designated Forwarder election (governed by Type-4 routes), and split-horizon filtering to prevent traffic loops.

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MCQeasy

Which BGP address family must be enabled under the BGP neighbor configuration to exchange EVPN routes between PE routers?

A.inet-unicast

B.evpn signaling (or l2vpn evpn)

C.vpls-signaling

D.iso-unicast

AnswerB

The EVPN address family is required to exchange all EVPN route types (1 through 5).

Why this answer

To exchange EVPN routing information, the 'evpn signaling' or 'l2vpn evpn' address family must be configured under the BGP protocol hierarchy and neighbor sessions.

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Multi-Selecthard

Which TWO of the following statements accurately describe EVPN Route Type 2 (MAC/IP Advertisement Route)? (Choose two)

Select 2 answers

A.It is exclusively used to elect the Designated Forwarder for multicast traffic.

B.It is only generated when BUM traffic flooding occurs.

C.It replaces BGP L3VPN route targets for core routing.

D.It can carry both a MAC address and an IP address in a single control-plane update.

E.It is used by PE routers to advertise MAC addresses learned from local attachment circuits to remote PEs.

AnswersD, E

Type 2 routes support advertising MAC and IP bindings together to optimize ARP suppression and host routing.

Why this answer

Type 2 routes advertise MAC addresses and optionally host IP addresses. They play a critical role in both Layer 2 bridging and Integrated Routing and Bridging (IRB) host reachability.

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MCQmedium

An engineer configures an EVPN instance with multiple bridge domains. Each bridge domain requires a unique VNI. Where are the VNI values mapped to their respective bridge domains in Junos OS?

A.Under protocols bgp neighbor configuration

B.Under interfaces loopback unit 0 vni

C.Under policy-options community definition

D.Under routing-instances <name> bridge-domains <domain-name> vni <id>

AnswerD

VNI mapping is defined directly within the specific bridge-domain configuration.

Why this answer

In Junos OS, VNI values are mapped under the 'bridge-domains' hierarchy using the 'vni <id>' statement.

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Multi-Selectmedium

Which TWO of the following statements correctly describe the operation and benefits of EVPN MAC mobility? (Choose two)

Select 2 answers

A.It forces BGP session resets whenever a MAC address moves between subnets.

B.It uses sequence numbers attached to Type-2 routes to track host movement between different PEs.

C.It is exclusively used for Route Type 4 Designated Forwarder election.

D.It prevents traffic blackholing when a virtual machine or host moves from one multi-homed attachment circuit to another.

E.It requires Spanning Tree Protocol to be enabled to detect host migration.

AnswersB, D

Sequence numbers increment upon each move to ensure the network recognizes the most recent location of the MAC.

Why this answer

EVPN MAC mobility uses sequence numbers in the MAC Mobility Extended Community to detect when a host moves between PEs, preventing blackholing and updating forwarding tables correctly.

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MCQeasy

When configuring VXLAN data plane encapsulation inside an EVPN routing instance on Junos OS, which logical interface type must be bound to the bridge domain to provide VXLAN VNI mapping?

A.lo0.0

B.gre0

C.VLAN interface (vlan statement with vni)

D.fxp0

AnswerC

Bridge domains configured with a specific vni identifier handle the mapping between VLANs and VXLAN VNIs.

Why this answer

In Junos OS, VXLAN encapsulation is configured using logical tunnel interfaces or integrated routing and bridging (IRB) interfaces mapped via a vni statement under the bridge-domains hierarchy.

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MCQmedium

An administrator notices that broadcast, unknown unicast, and multicast (BUM) traffic sent from a local host is looping back to the originating multi-homed PE when using an all-active Ethernet segment. Which mechanism prevents this loop in EVPN?

A.BGP Best Path Selection algorithm

B.EVPN Split Horizon filtering using ESI labels

C.Designated Forwarder (DF) election

D.Spanning Tree Protocol (STP) root guard

AnswerB

Split horizon filtering ensures that a PE does not echo BUM traffic back to an Ethernet segment it shares with another PE.

Why this answer

EVPN uses Split Horizon filtering via the ESI Label Extended Community or local split-horizon checks to ensure that BUM traffic received from a remote PE on a shared Ethernet segment is not sent back out to the same segment.

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