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In a VXLAN-EVPN fabric, a VTEP advertises a Type 2 MAC/IP route primarily to achieve which outcome?

Distribute remote MAC and IP bindings so other VTEPs can perform ARP suppression locally

Announce the availability of a new VTEP loopback for underlay ECMP

Signal the establishment of a new VXLAN tunnel with a static VNI assignment

Flush all remote MAC addresses associated with an Ethernet Segment during failover

to track

2026 Statistics

Key Facts: JNCIS-DC Exam

Exam Questions

Juniper Networks

90 min

Time Limit

Juniper Networks

$300

Exam Fee

Pearson VUE

3 years

Certification Validity

Juniper Networks

EVPN Route Types Tested

JNCIS-DC Content

100

Free Practice Questions

OpenExamPrep

The JNCIS-DC (Juniper Networks Certified Internet Specialist — Data Center) validates hands-on expertise with VXLAN-EVPN fabrics on Juniper QFX switches. Key topics include all 5 EVPN route types, ERB vs CRB fabric design, eBGP unnumbered underlay, EVPN multi-homing (ESI, all-active/single-active), Juniper Apstra intent-based networking, and data center interconnect (DCI). Widely recognized by enterprises and cloud providers using Juniper data center infrastructure. Earns Junos Specialist status for 3 years.

Sample JNCIS-DC Practice Questions

Try these sample questions to test your JNCIS-DC exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In a VXLAN-EVPN fabric, a VTEP advertises a Type 2 MAC/IP route primarily to achieve which outcome?

A.Distribute remote MAC and IP bindings so other VTEPs can perform ARP suppression locally

B.Announce the availability of a new VTEP loopback for underlay ECMP

C.Signal the establishment of a new VXLAN tunnel with a static VNI assignment

D.Flush all remote MAC addresses associated with an Ethernet Segment during failover

Explanation: An EVPN Type 2 (MAC/IP Advertisement) route carries a MAC address and optionally its associated IP address. Remote VTEPs install this binding in their local MAC-VRF and IP-VRF tables, enabling ARP/ND suppression — the VTEP answers ARP requests on behalf of remote hosts rather than flooding across the overlay. This dramatically reduces BUM (Broadcast, Unknown unicast, Multicast) traffic in the fabric.

2An EVPN Type 3 Inclusive Multicast Ethernet Tag (IMET) route is generated by a VTEP when:

A.The VTEP needs to join a BUM replication tree and advertise its ability to receive broadcast, unknown unicast, and multicast traffic for a given EVI

B.A remote host's MAC address is learned dynamically through data-plane flooding

C.An inter-DC EVPN gateway requires prefix routing to leak Type 5 routes between VRFs

D.An ESI link failure triggers an immediate mass withdrawal of all MAC routes for that segment

Explanation: The EVPN Type 3 IMET route (also called Inclusive Multicast Route) is how a VTEP announces participation in BUM traffic distribution for a specific EVI/VNI. In ingress-replication mode (the most common Juniper QFX/EX deployment), the VTEP lists its own VTEP IP in the PMSI Tunnel attribute; every remote VTEP that imports the route adds the originator to its replication list for that VNI.

3Which EVPN route type carries an IP prefix (rather than a MAC address) and is used to leak Layer 3 routes between VRFs in a VXLAN fabric?

A.Type 5 IP Prefix Route

B.Type 2 MAC/IP Advertisement Route

C.Type 4 Ethernet Segment Route

D.Type 3 Inclusive Multicast Ethernet Tag Route

Explanation: EVPN Type 5 (IP Prefix Route) was introduced in RFC 9136 to extend EVPN beyond L2 bridging. It carries an IP prefix and mask (v4 or v6) along with a Gateway IP, enabling full L3 inter-VRF routing — including DCI scenarios — without requiring a host MAC address. On Juniper QFX platforms, Type 5 is the mechanism for advertising summarized prefixes from tenant VRFs to remote VTEPs and WAN gateways.

4In EVPN multi-homing, the Type 1 Ethernet Auto-Discovery (A-D) route per-ESI is primarily used to:

A.Enable mass withdrawal of all MAC/IP routes for an Ethernet Segment when the uplink to that segment fails

B.Advertise a host IP address to a remote VTEP for ARP suppression

C.Announce VTEP reachability for BUM traffic replication across all VNIs

D.Carry an IP prefix from a tenant VRF to a WAN gateway

Explanation: The EVPN Type 1 per-ESI (Ethernet Auto-Discovery per Ethernet Segment) route is withdrawn when all links in that ESI go down. Remote VTEPs that receive the withdrawal immediately flush all MAC/IP entries associated with that ESI, providing fast convergence (mass withdrawal) without having to wait for individual Type 2 route timeouts. A separate per-EVI A-D route controls aliasing and split-horizon for each EVI.

5An Ethernet Segment Identifier (ESI) in EVPN multi-homing is configured on:

A.The interface(s) connecting the leaf switches to the multi-homed CE device, using the same ESI value on all participating leaf switches

B.The BGP peer group between spine and leaf, to identify the underlay link bundle

C.Each VXLAN tunnel interface on the leaf to uniquely identify the VNI-to-VRF mapping

D.The loopback interface of each leaf to distinguish its VTEP from others in the same EVPN instance

Explanation: In EVPN multi-homing (all-active or single-active), the same ESI value is configured on all leaf switches that share a physical link or LAG to the same CE (server or router). Juniper JunOS uses 'esi' under the interface or ae (aggregated Ethernet) configuration. All leaf switches with the same ESI form an Ethernet Segment, and EVPN control plane uses Type 1 and Type 4 routes to synchronize state and elect a Designated Forwarder.

6In an EVPN Type 4 Ethernet Segment (ES) route, what is the primary purpose?

A.Allow VTEPs sharing the same ESI to discover each other and elect a Designated Forwarder for BUM traffic

B.Advertise the host MAC and IP addresses learned on a multi-homed server

C.Announce IP prefix routes from a tenant VRF for inter-DC routing

D.Signal participation in BUM ingress-replication lists for a specific EVI

Explanation: EVPN Type 4 (Ethernet Segment Route) carries the ESI and the advertising PE's VTEP IP. By importing Type 4 routes from peers sharing the same ESI (identified via the ES-Import route target), each PE discovers its co-located multi-homing peers. From this set, they elect a Designated Forwarder (DF) per EVI, ensuring BUM traffic is delivered exactly once — the DF sends BUM toward the CE, while non-DF peers discard it on the ESI-facing port.

7What distinguishes Edge-Routed Bridging (ERB) from Centrally-Routed Bridging (CRB) in a VXLAN EVPN fabric?

A.In ERB, inter-VLAN routing is performed at each leaf (VTEP), keeping traffic local; in CRB, routing is centralized on spine or border-leaf devices

B.In ERB, all routing is handled exclusively by spine switches using traditional SVI interfaces; leaves only perform L2 bridging

C.CRB extends routing to each leaf for micro-segmentation, while ERB centralizes security policy enforcement on a DMZ firewall

D.ERB requires an MPLS underlay, whereas CRB operates over VXLAN UDP encapsulation

Explanation: In ERB (the default on modern Juniper QFX data center fabrics), each leaf switch hosts a Layer 3 gateway (Anycast GW) for each VLAN it carries. Inter-VLAN traffic is routed locally at the ingress leaf, then forwarded as pure L3 across the underlay — the packet never traverses the spine as bridged traffic. In CRB, leaves are pure L2 VTEPs; all routed traffic is hairpinned to centralized route-reflector spines or border leaves for L3 forwarding, increasing east-west latency and spine bandwidth consumption.

8In a Juniper data center fabric using ERB, what is the purpose of the Anycast Gateway MAC?

A.All leaf switches in the fabric share one virtual gateway MAC address for each VLAN, ensuring the gateway is always local regardless of which leaf a host connects to

B.The Anycast Gateway MAC is the physical MAC burned into each QFX ASIC for layer-2 forwarding

C.It is a per-leaf unique MAC that is advertised via EVPN Type 5 to enable prefix routing

D.It eliminates the need for a BGP underlay by providing an in-band management channel

Explanation: The Anycast Gateway (or Distributed Gateway) MAC — configured under 'set routing-instances <vrf> protocols evpn default-gateway' or through IRB anycast on Juniper — is the same MAC on every leaf in the fabric for a given VLAN. When a host sends an ARP for its gateway, any leaf can respond with this shared MAC, meaning the host's default gateway is always its directly connected leaf. This avoids a first-hop IP redirect and keeps inter-VLAN traffic symmetric.

9In a Juniper QFX eBGP underlay for a data center spine-leaf fabric, which of the following is TRUE about unnumbered eBGP?

A.Unnumbered eBGP uses IPv6 link-local addresses for neighbor discovery and peer sessions, then carries IPv4 NLRI using RFC 5549 next-hop encoding

B.Unnumbered eBGP requires each interface to be configured with a /30 IPv4 address and a matching ASN on both ends

C.Unnumbered eBGP is a proprietary Juniper feature that uses IS-IS hellos to establish BGP sessions

D.Unnumbered eBGP eliminates the need for any loopback interface on the spine or leaf switches

Explanation: Unnumbered eBGP (RFC 5549) removes the need to assign a /30 or /31 IPv4 subnet to every fabric link. Instead, BGP peers are discovered via IPv6 link-local addresses derived from the interface MAC. Once the session is established, IPv4 routes (including VTEP loopback prefixes) are advertised with an IPv6 link-local next-hop encoded per RFC 5549. Juniper JunOS implements this via 'neighbor <interface> family inet unicast extended-nexthop' configuration.

10Why is OSPF typically less preferred than eBGP as the VXLAN underlay routing protocol in large Juniper data center fabrics?

A.OSPF uses a single flat area and has limited scalability for large numbers of ECMP paths and prefixes, while eBGP offers simpler per-link failure isolation and fine-grained policy control

B.OSPF cannot advertise VTEP loopback addresses, making it incompatible with VXLAN tunnel endpoint discovery

C.eBGP supports ECMP natively while OSPF does not support equal-cost multi-path at all

D.OSPF requires a license on Juniper QFX platforms whereas eBGP is included by default

Explanation: In large-scale (100+ leaf) fabrics, OSPF's link-state flooding and full-mesh adjacency model create scalability concerns. eBGP with a different AS per leaf provides inherent failure isolation (a bad advertisement from one leaf does not flood the entire domain), predictable ECMP via multipath configuration, and supports fine-grained policy via route-maps/policy-statements. This is why major vendors, including Juniper (as documented in the DC design guides), recommend eBGP underlay for scalable CLOS fabrics.

About the JNCIS-DC Exam

Intermediate-to-advanced data center specialist certification validating VXLAN-EVPN design, Juniper QFX fabric operations, and DCI expertise. JNCIS-DC is the specialist tier in the Juniper Data Center certification track.

Questions

65 scored questions

Time Limit

90 minutes

Passing Score

Pass/Fail (scaled)

Exam Fee

$300 (Juniper Networks / Pearson VUE)

JNCIS-DC Exam Content Outline

35%

VXLAN-EVPN Overlay

EVPN route types 1-5, ARP suppression, MAC mobility, multi-homing, split-horizon

25%

Data Center Fabric Design

ERB vs CRB, IRB, Anycast Gateway, symmetric vs asymmetric IRB, CLOS topology

20%

Underlay Routing

eBGP numbered/unnumbered, OSPF, ASN design, ECMP, BFD, route reflectors

10%

DCI and Juniper Apstra

VXLAN stitching, MP-BGP EVPN DCI, Apstra blueprints and intent-based networking

10%

DC Security and QoS

Microsegmentation, GBP/SGT, MACsec, PFC, ETS, lossless Ethernet for RoCE

How to Pass the JNCIS-DC Exam

What You Need to Know

Passing score: Pass/Fail (scaled)
Exam length: 65 questions
Time limit: 90 minutes
Exam fee: $300

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

JNCIS-DC Study Tips from Top Performers

1Master all 5 EVPN route types and their exact purposes — Type 1 (A-D), Type 2 (MAC/IP), Type 3 (IMET), Type 4 (ES), Type 5 (IP Prefix)

2Understand the difference between ERB and CRB, and how IRB with Anycast Gateway works in an ERB fabric

3Study EVPN multi-homing thoroughly: ESI, all-active vs single-active, DF election, aliasing, split-horizon

4Practice reading and interpreting JunOS 'show evpn database', 'show evpn instance', 'show bgp summary', and 'show vxlan tunnel' outputs

5Learn Juniper Apstra's key objects: Blueprint, Logical Device, Rack Type, Virtual Network, Connectivity Template

6Understand eBGP unnumbered (RFC 5549) and why ASN-per-leaf is used in CLOS fabrics

Frequently Asked Questions

What is the JNCIS-DC exam?

The JNCIS-DC (Juniper Networks Certified Internet Specialist — Data Center) is Juniper's intermediate-level data center certification. It validates expertise in VXLAN-EVPN overlay design, Juniper QFX fabric deployment, eBGP/OSPF underlay routing, EVPN multi-homing (ESI), Juniper Apstra intent-based networking, and data center interconnect (DCI). The exam consists of 65 multiple-choice questions completed in 90 minutes, administered through Pearson VUE.

How hard is the JNCIS-DC exam?

JNCIS-DC is considered intermediate-to-advanced difficulty. It requires solid understanding of EVPN route types 1-5, the mechanics of ARP suppression, symmetric vs asymmetric IRB, all-active vs single-active ESI multi-homing, and Juniper-specific configuration (JunOS CLI). Candidates typically need 60-90 hours of study and hands-on lab experience with Juniper QFX switches or Juniper's vLab environments.

What should I study for JNCIS-DC?

Focus on: (1) VXLAN-EVPN — all 5 EVPN route types and their purposes; (2) ARP suppression and MAC mobility; (3) EVPN multi-homing: ESI, all-active vs single-active, DF election; (4) ERB vs CRB design and IRB (Anycast Gateway); (5) eBGP underlay design — numbered, unnumbered (RFC 5549), ASN-per-leaf; (6) Juniper Apstra — blueprints, logical devices, rack types, connectivity templates; (7) DC security: GBP/SGT microsegmentation; (8) DCI: VXLAN stitching and MP-BGP EVPN. Juniper's official study guides and Junos Day One books are excellent resources.

What is the prerequisite for JNCIS-DC?

Juniper recommends JNCIA-DC (Associate level) as preparation, but it is not a hard prerequisite. Practical experience with Juniper QFX switches and a solid understanding of networking fundamentals (BGP, VXLAN basics, L2/L3 networking) are more important than holding the JNCIA-DC certification before attempting JNCIS-DC.

How long is JNCIS-DC valid?

The JNCIS-DC certification is valid for 3 years. To recertify, you can pass the current JNCIS-DC exam or achieve a higher-level Juniper data center certification (JNCIP-DC or JNCIE-DC) before the certification expires.

What is the JNCIS-DC exam fee?

The JNCIS-DC exam fee is approximately $300 USD, administered through Pearson VUE. Prices may vary by region. Juniper sometimes offers discounted exam vouchers through authorized training partners or as part of training bundles.

What comes after JNCIS-DC?

After JNCIS-DC, the next step in the Juniper Data Center track is JNCIP-DC (Professional) and ultimately JNCIE-DC (Expert — lab exam). You can also pursue JNCIS certifications in other tracks (Enterprise, Security, Service Provider) to broaden your Juniper credentials.