Nokia 4A0-D03 Real Exam Dumps [July 2026 Update]

Layer 2 EVPN and Layer 3 EVPN look superficially similar from the outside: both use BGP as the control plane, both use VXLAN as the data plane, and both use MAC-VRF network instances. The exam knows this and tests the forwarding model difference directly. In asymmetric routing, the ingress leaf does both the bridging and the routing. The egress leaf only bridges. The result is that every leaf in the fabric must have the MAC-VRF for every remote subnet, even subnets it does not locally host, because the ingress leaf must know the destination’s MAC address to construct the VXLAN header. In symmetric routing, both leaves perform routing: the ingress leaf routes to its IP-VRF and the egress leaf routes from its IP-VRF. The result is that leaves only need IP-VRF entries for subnets they route, not for every remote subnet. Candidates who understand L2 EVPN but assume L3 EVPN is “the same thing but with routing added” will fail the asymmetric vs. symmetric routing questions that specifically test the per-leaf state implications of each model.

The Nokia 4A0-D03 (SR Linux EVPN and Data Center Interconnect) is an exam in the Nokia Certified Data Center Fabric Network Expert certification path. It tests practical knowledge of EVPN-based networking in Nokia SR Linux environments: L2 EVPN services (MAC-VRF), L3 EVPN services (IP-VRF with IRB interfaces), EVPN multi-homing, and Data Center Interconnect between Nokia SR Linux leaf/spine fabric and the Nokia 7750 SR as a DC/WAN gateway. The exam consists of 40 multiple-choice and scenario-based questions in 90 minutes (110 minutes total including an introductory survey). The exam costs $125 and is available through Nokia’s certification platform.

Cert Empire’s 4A0-D03 exam questions are built with the asymmetric/symmetric routing distinction, EVPN route type specifics, and SR Linux configuration-level knowledge the real exam tests.

Exam Snapshot

What the 4A0-D03 Exam Tests

Section 1: DC Fabric Fundamentals (SR Linux Platform)

Before EVPN is introduced, the exam establishes that candidates understand the SR Linux platform and its data plane foundation.

SR Linux product architecture: The Nokia Service Router Linux (SR Linux) is Nokia’s data center operating system built on a microservices architecture. Unlike traditional monolithic network operating systems, SR Linux separates routing daemons and management functions into independent processes with defined APIs. The exam tests the CLI structure and how network instances are organized.

Network instances: SR Linux organizes forwarding tables into network instances. A network instance is a routing domain (VRF-equivalent) that contains interfaces, routing tables, and forwarding decisions. The exam tests the three primary network instance types:

• default: the default routing instance; all interfaces belong to the default instance unless assigned elsewhere.
• mac-vrf: a Layer 2 forwarding domain; equivalent to a bridge domain or VLAN domain in traditional networking. Contains MAC tables and flooding domains.
• ip-vrf: a Layer 3 routing domain; equivalent to a VRF in traditional networking. Contains IP routes and FIBs.

Integrated Routing and Bridging (IRB) interfaces: IRBs connect a mac-vrf (L2 domain) to an ip-vrf (L3 domain), enabling hosts in the MAC-VRF to be routed through the IP-VRF. A single IRB interface has both a MAC address and an IP address. The IP address is the default gateway for hosts in the MAC-VRF domain. The exam tests how IRBs are configured and what role they play in L3 EVPN services.

BGP routing protocol in SR Linux: MP-BGP (Multiprotocol BGP) is the control plane for EVPN. The exam tests BGP configuration basics in SR Linux: enabling the EVPN address family alongside IPv4, configuring peer groups, and understanding how BGP peering is structured in a leaf/spine topology (all leaves peer with spine route reflectors rather than forming a full mesh).

Equal-Cost Multipath (ECMP) and BGP multipath: SR Linux supports ECMP for both underlay routing (multiple equal-cost paths between leaf and spine) and EVPN overlay (traffic distributed across multiple VTEP endpoints). The exam tests how ECMP is configured and what its impact is on traffic distribution.

Section 2: EVPN Overlay (BGP Control Plane)

EVPN address family: EVPN is a BGP address family (AFI 25, SAFI 70) that carries MAC and IP address reachability information as BGP NLRI (Network Layer Reachability Information). The exam tests how EVPN routes are different from standard IP routes in terms of what information they carry.

Route Distinguisher (RD) and Route Target (RT):

• RD: Makes each route globally unique in MP-BGP by appending a unique per-PE prefix to each NLRI. Two different PEs can advertise overlapping IP prefixes with different RDs.
• RT: Controls which routes are imported into which VRF instances. Routes are exported with one RT and imported by remote PEs that are configured to import that RT. Route targets are how EVPN constructs services: all leaf switches in an L2 EVPN service import the same RT.

EVPN Route Types: The exam tests all five major EVPN route types and what each carries:

• RT1 (Ethernet Auto-Discovery): Used for multi-homing; advertises the Ethernet Segment Identifier (ESI) to signal multi-homed connectivity.
• RT2 (MAC/IP Advertisement): Carries a MAC address, optionally an IP address, and an optional VXLAN VNI. Used for control-plane MAC learning: when a host sends traffic in an L2 EVPN, the local leaf advertises the host’s MAC (and IP) as an RT2 to all remote leaves via the route reflector. A confirmed exam question: which EVPN route type is used by a leaf to advertise a host’s MAC address to remote leaves? RT2.
• RT3 (Inclusive Multicast Ethernet Tag / IMET): Used for BUM (Broadcast, Unknown Unicast, Multicast) traffic forwarding; establishes the VXLAN tunnel flood list for multicast traffic in L2 EVPN.
• RT4 (Ethernet Segment): Carries ES-level information for multi-homing designated forwarder election.
• RT5 (IP Prefix Route): Carries IP prefixes (not host /32 or /128 routes); used in L3 EVPN symmetric routing for inter-subnet routing.

Route Reflector (RR): Route reflectors eliminate the requirement for a full mesh of BGP sessions between all leaf switches. Instead, each leaf establishes a BGP EVPN session only with the route reflectors (typically the spine switches in Nokia data center fabric). A confirmed exam question: which statement about route reflectors in the BGP EVPN control plane is FALSE? The statement that “each leaf router will have a unique autonomous system number for the BGP EVPN session to the route reflectors” is false when iBGP (same AS) is used, which is the common Nokia fabric design.

Section 3: Layer 2 EVPN

L2 EVPN service model: In L2 EVPN, a MAC-VRF instance on each leaf switch represents a broadcast domain spanning multiple leaf switches. Hosts attached to any leaf in the same L2 EVPN can communicate at Layer 2 as if they were on the same physical switch.

MAC learning in EVPN: In traditional Ethernet, MACs are learned by flooding traffic and observing source MAC addresses. In EVPN, MAC learning happens in the BGP control plane: when a host sends a frame, the local leaf learns the MAC, advertises it as an RT2 EVPN route via BGP, and all remote leaves install the MAC in their MAC tables without needing to flood traffic.

Proxy-ARP: In EVPN, the local leaf responds to ARP requests for remote hosts using information learned from RT2 MAC/IP advertisements (which include both the MAC and IP of the host). This is called proxy-ARP: the leaf answers ARP on behalf of remote hosts, eliminating the need to flood ARP requests across the VXLAN fabric. A confirmed exam question: what is the need for proxy-ARP in an L2 EVPN? The leaf uses MAC/IP information (from RT2 routes) to populate the ARP cache for the MAC-VRF, enabling it to respond to ARP requests for remote hosts without flooding.

MAC protection and MAC duplication: EVPN includes mechanisms to detect and prevent MAC address duplication (the same MAC appearing behind different VTEP endpoints, which indicates a configuration error or MAC move). MAC move (genuine host movement between leaves) is handled by the MAC mobility extended community in RT2 routes; the route with the highest sequence number wins.

L2 EVPN multi-homing (Single-Active and All-Active):

• All-Active multi-homing: A host is connected to two leaf switches simultaneously (via LAG). Both leaves can forward traffic to and from the host. The Designated Forwarder (DF) election determines which leaf forwards BUM traffic for the Ethernet Segment.
• Single-Active multi-homing: One leaf is active and the other is a standby. Traffic to the host always goes through the active leaf. The standby takes over only if the active fails.

A confirmed exam question: which of the following statements describes the operation of multi-homing single-active mode in Nokia SR Linux? The active leaf forwards all traffic; the standby leaf takes over if the active link fails, but does not forward traffic while the active link is operational.

Section 4: Layer 3 EVPN

L3 EVPN with IRB: L3 EVPN adds IP routing across the EVPN fabric by connecting MAC-VRFs (L2 domains) to IP-VRFs (L3 domains) via IRB interfaces. Each IRB interface has an IP address that serves as the default gateway for hosts in the connected MAC-VRF.

Anycast gateway: In all-active multi-homing, the same IRB IP and MAC address is configured identically on all leaves that host the same MAC-VRF. When a host sends a packet to its gateway, whichever leaf receives it can process it without additional forwarding. This is the anycast gateway pattern: the same gateway IP/MAC exists at multiple leaves simultaneously. A confirmed exam question: an IP address configured on an IRB interface using anycast gateway CAN be used on another IRB interface in the same L3 EVPN (the same IP/MAC is shared across multiple leaves for the same subnet).

Asymmetric routing:

• The ingress leaf receives the packet from the source host and performs both the L2 lookup (to find the next-hop VTEP for the destination MAC) and the L3 routing decision.
• The egress leaf only performs L2 bridging in its MAC-VRF (the packet arrives already routed).
• Consequence: every leaf must have a MAC-VRF for every subnet in the L3 EVPN, even subnets with no local hosts, so the ingress leaf can resolve the destination MAC. This creates significant per-leaf state.

Symmetric routing:

• Both the ingress and egress leaf perform routing.
• The ingress leaf routes from the source subnet IP-VRF and uses RT5 (IP Prefix Route) to forward to the egress leaf’s IP-VRF.
• The egress leaf routes from its IP-VRF to the destination host’s MAC-VRF.
• Consequence: leaves only need IP-VRF entries for subnets they actually host. Scale is improved because not every leaf needs every remote subnet’s MAC-VRF.

RT2 vs. RT5 in symmetric routing: A confirmed exam question: in a L3VPN using symmetric routing, which route type carries IP prefix information? RT5 (IP Prefix Route) carries subnet prefixes for inter-subnet routing. RT2 carries the IRB’s MAC and IP address (for the anycast gateway) but not the full subnet prefix.

PE-CE BGP: L3 EVPN supports BGP peering between the leaf (PE) and a customer VNF or router (CE) attached to the IP-VRF. The exam tests how BGP path attributes are propagated and the default BGP behavior with a new CE peer (by default, BGP will not exchange updates until explicitly activated).

Section 5: Data Center Interconnect (DCI)

DCI use cases and architecture: DCI connects multiple physically separate data centers so that workloads can span sites or be migrated between them. The Nokia SR Linux fabric (leaf/spine) handles local DC traffic; the Nokia 7750 SR acts as the DC/WAN gateway for inter-DC traffic.

Gateway-less DCI: The most scalable DCI architecture where EVPN routes from one DC are extended directly to leaf switches in the remote DC via the WAN transport, without a centralized gateway that all inter-DC traffic must pass through. The exam tests what gateway-less means for BGP route distribution across the DCI.

VXLAN tunnel stitching: At the DCI boundary, VXLAN tunnels from the data center fabric must be stitched together with the WAN transport. The Nokia 7750 SR performs this stitching function, translating between data center VXLAN and WAN transport encapsulation.

BGP route policies in DCI: The exam tests how route policies are used to control which EVPN routes are advertised from the DC fabric into the WAN and from the WAN into remote DC fabrics. Incorrect route policy configuration at the DCI boundary can cause route leakage (routes that should not cross the DCI boundary do) or route suppression (valid routes that should be shared are blocked).

SR Linux and Nokia 7750 SR interoperability: Both platforms run the same Nokia SRlinux/SROS software stack with compatible EVPN implementations. The exam tests the key interoperability points and what configuration is required for the two platforms to exchange EVPN routes correctly.

What to Expect on Exam Day

• 40 scenario-based questions in 90 minutes (plus 20 minutes for an introductory survey).
• Questions test EVPN route type identification, forwarding model understanding (asymmetric vs. symmetric), and SR Linux-specific configuration knowledge.
• Exhibit-based questions are common: a topology diagram or configuration snippet is shown and candidates must answer based on what it shows.
• Immediate pass/fail result.

5 Study Tips for Nokia 4A0-D03

• Tip 1: Master the asymmetric vs. symmetric L3 EVPN routing distinction. Know what each model requires from each leaf in terms of per-leaf state (every-subnet MAC-VRF for asymmetric; only local-subnet IP-VRF for symmetric). This is the most distinguishing topic on the exam.
• Tip 2: Know all five EVPN route types by number, what each carries, and when each is advertised. RT2 for MAC/IP learning is the most frequently tested; RT5 for symmetric routing is the second most.
• Tip 3: Understand proxy-ARP in L2 EVPN: the leaf uses RT2 MAC/IP information to answer ARP requests for remote hosts, preventing ARP flooding across the fabric.
• Tip 4: Study single-active vs. all-active multi-homing with attention to which leaf forwards traffic in each mode and what the Designated Forwarder election determines.
• Tip 5: Practice with Cert Empire’s 4A0-D03 exam questions including exhibit-based topology questions that require tracing forwarding paths through a multi-leaf SR Linux fabric.

Best Study Resources

• Cert Empire 4A0-D03 exam questions PDF and practice simulator (2026 edition).
• Nokia SR Linux EVPN and Data Center Interconnect official exam page (nokia.com/networks/training/dcf/exams/sr-linux-evpn-dci).
• Nokia SR Linux EVPN and DCI course materials (nokia.com/networks/training/dcf/courses/sr-linux-evpn-dci).
• Nokia 4A0-D03 official practice exam (downloadable from Nokia exam page).
• My DCF Learning Labs (nokia.com hands-on lab environment for SR Linux).

Career Opportunities After 4A0-D03

• Data Center Network Engineer (SR Linux)
• Cloud Infrastructure Engineer
• Data Center Fabric Architect
• Nokia DCF Solutions Specialist
• Network Virtualization Engineer
• DC/WAN Integration Engineer

Nokia SR Linux expertise is growing in demand as data centers adopt modern containerized fabric architectures. Data center fabric engineers with Nokia expertise earn between USD 100,000 and USD 145,000 annually.

Why Candidates Choose Cert Empire for Nokia 4A0-D03 Preparation

✔ Asymmetric vs. symmetric routing questions at per-leaf-state depth. Our questions test the practical consequence of each model (every-subnet MAC-VRF requirement for asymmetric; per-route-target IP-VRF for symmetric) not just the conceptual names.

✔ EVPN route type identification questions with what-each-carries specificity. We test RT1-RT5 by number, content, and when each is generated, including the RT2 MAC/IP carrier and RT5 IP Prefix carrier in symmetric routing.

✔ Proxy-ARP mechanism questions. Our questions test how proxy-ARP uses RT2 MAC/IP information to avoid ARP flooding in L2 EVPN environments.

✔ Practice under real exam conditions with the Cert Empire Exam Simulator. Our 4A0-D03 simulator runs 40 questions in 90 minutes with exhibit-based topology questions and SR Linux EVPN coverage across all five exam sections.

✔ Instant access, 90-day free updates, and 24/7 support. As Nokia updates 4A0-D03 content, your materials update automatically. Our support team is available around the clock.

✔ Backed by a full money-back guarantee. If our exam questions do not help you pass, we refund your purchase with no conditions.

Readiness Check

1. In a Nokia SR Linux L3 EVPN using asymmetric routing, Leaf-1 hosts Subnet-A (192.168.1.0/24) and Leaf-2 hosts Subnet-B (192.168.2.0/24). A host in Subnet-A wants to send a packet to a host in Subnet-B. What MAC-VRF instances must be configured on Leaf-1 for this forwarding to work, why does asymmetric routing require this, and what would be different if symmetric routing were used instead?
2. A leaf router in a Nokia SR Linux fabric is configured with an L3 EVPN IP-VRF and receives an RT5 update from a remote leaf. What does the RT5 update carry, when is an RT5 update preferred over an RT2 update for inter-subnet routing, and what is the overlay index that an RT5 update can include to define next-hop information?
3. Leaf-1 and Leaf-2 are both connected to the same multi-homed host via a LAG. The L2 EVPN is configured for all-active multi-homing. Leaf-3 (which is not multi-homed to this host) receives BUM traffic that must be delivered to the host. Identify which leaf is responsible for forwarding the BUM traffic to the multi-homed host, what election process determines this responsibility, and which EVPN route type carries the information required for this election.
4. A network engineer configures an IRB interface on Leaf-1 with IP address 192.168.100.254 as an anycast gateway for a MAC-VRF in an L3 EVPN. They want to use the same IP address 192.168.100.254 on an IRB interface for the same MAC-VRF on Leaf-2. Is this configuration permitted in the anycast gateway model? What specific statement would be TRUE about what hosts in the MAC-VRF use as their gateway?
5. In a Nokia SR Linux L2 EVPN with proxy-ARP configured, Host-A (MAC 00:11:22:33:44:55, IP 10.0.0.1) is connected to Leaf-1. Host-B (IP 10.0.0.2) is connected to Leaf-2 and has been advertised via RT2. When Host-A sends an ARP request for 10.0.0.2, which device responds, how does it know the answer, and what is the benefit of this behavior compared to flooding the ARP request across the VXLAN fabric?

FAQS

What is the Nokia 4A0-D03 exam?

The 4A0-D03 is the Nokia SR Linux EVPN and Data Center Interconnect exam. It validates expertise in EVPN-based networking using Nokia’s SR Linux platform, including L2 and L3 EVPN services, multi-homing, and data center interconnection with the Nokia 7750 SR.

How many questions are on the 4A0-D03 exam?

40 multiple-choice and scenario-based questions. The total exam appointment is 110 minutes, which includes 90 minutes of exam time plus a 20-minute introductory survey.

What is the difference between asymmetric and symmetric routing in L3 EVPN?

In asymmetric routing, the ingress leaf performs both bridging and routing; the egress leaf only bridges. Every leaf must have a MAC-VRF for every remote subnet. In symmetric routing, both the ingress and egress leaf perform routing via their IP-VRFs. Leaves only need IP-VRF entries for subnets they host, improving scale.

Which EVPN route type carries host MAC and IP address information?

Route Type 2 (RT2, MAC/IP Advertisement) carries host MAC addresses and optionally host IP addresses. It is used for control-plane MAC learning in L2 EVPN and for gateway MAC/IP advertisement in L3 EVPN.

What is proxy-ARP in EVPN and why is it used?

Proxy-ARP allows a leaf switch to respond to ARP requests on behalf of remote hosts using MAC/IP information learned from RT2 EVPN routes. This eliminates the need to flood ARP requests across the VXLAN fabric, reducing BUM traffic and improving scalability.

Related Certifications Worth Exploring

Nokia data center fabric professionals building toward the expert credential will find our Nokia certification exam resources cover the foundation DC fabric knowledge that the 4A0-D03 exam assumes candidates already have. For those expanding Nokia expertise into service provider networking alongside data center, our Nokia 4A0-103 MPLS exam questions page covers the MPLS knowledge that connects data center EVPN fabric to WAN service provider networks in DCI scenarios.