[Aug 27, 2026] 4A0-D03 Exam Dumps, 4A0-D03 Practice Test Questions
Free 4A0-D03 Study Guides Exam Questions and Answer
NEW QUESTION # 23
Which of the following four symmetric routing options does NOT require the use of an EVPN route-type 2?
- A. Prefix routing interface-ful unnumbered
- B. Prefix routing interface-less
- C. Prefix routing interface-ful numbered
- D. Host routing
Answer: C
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
EVPN route type 2 carries MAC/IP advertisement information. It is central to host-based routing and to designs where the fabric must distribute host MAC-to-IP bindings for integrated routing and bridging. In host routing, RT-2 is required because individual host reachability is signaled through MAC/IP advertisements. In interface-less prefix routing, RT-2 is still needed because the system relies on host or gateway MAC/IP information associated with the IRB and distributed gateway behavior. Interface-ful unnumbered designs may also require RT-2-style information to resolve next-hop or adjacency behavior because the routed interface does not use a conventional numbered next-hop model. Prefix routing with interface-ful numbered operation is different. In that model, the routed interface has explicit IP addressing and prefix reachability can be carried with L3 prefix routes without requiring EVPN RT-2 host MAC/IP advertisement as a dependency. Therefore, the symmetric routing option that does not require EVPN route type 2 is prefix routing interface-ful numbered. Reference: symmetric L3 EVPN routing models, RT-2 MAC/IP advertisements, prefix routing behavior.
NEW QUESTION # 24
Which of the following statements about PE-CE routing is FALSE?
- A. BGP is the preferred option for PE-CE routing as it scales better than static routing.
- B. The CE advertises BGP EVPN route type 5 updates to the PE and the PE forwards to other PEs.
- C. eBGP is preferred which means that the PE and CE are required to be in different autonomous systems.
- D. There are two methods to implement routing between the PE and CE, static and dynamic.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
PE-CE routing is the mechanism used to exchange customer prefix reachability between a provider edge or data center leaf and the attached customer edge router. It can be implemented statically or dynamically. Static routing is operationally simple but does not scale well when many prefixes or frequent changes are involved. BGP is preferred for larger deployments because it supports policy, route filtering, attributes, and automated advertisement of changing reachability. In most EVPN PE-CE designs, eBGP is preferred because it creates a clean routing boundary between the PE and CE, with each device operating in a different autonomous system. Option D is false because the CE does not advertise BGP EVPN route type 5 updates to the PE. The CE advertises ordinary IPv4 or IPv6 unicast prefixes over the PE-CE routing session. The PE then imports those customer prefixes into the IP-VRF and advertises them into the EVPN overlay as route type 5 IP Prefix routes toward other PEs. This distinction matters: EVPN signaling is a PE-to-PE overlay function, not a CE-originated EVPN control-plane role. Reference: PE-CE routing, eBGP, EVPN RT-5 prefix advertisement.
NEW QUESTION # 25
Which of the following EVPN route-types is used to implement aliasing?
- A. IP/MAC routes
- B. Ethernet segment routes
- C. AD per EVI routes
- D. AD per ES routes
Answer: C
NEW QUESTION # 26
Which of the following statements about utilizing asymmetric routing in an L3 EVPN network is FALSE?
- A. The ingress and egress PE routers will perform both MAC and IP forwarding.
- B. Each PE must have a full ARP table for all of the hosts in the L3 EVPN network.
- C. If a host interface's has two IP addresses, it must send out two separate EVPN route-type 2 updates for the MAC-VRF.
- D. All the MAC-VRFs connected to the L3 EVPN network must exist on each PE.
Answer: D
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
Asymmetric routing relies heavily on host MAC/IP information because the ingress PE performs routing into the destination subnet and then sends the frame across the overlay using the destination MAC-VRF/VNI. This means PEs require enough ARP and MAC/IP binding information to forward traffic toward remote hosts correctly. If a host has multiple IP addresses on the same interface, separate EVPN route type 2 advertisements may be needed to communicate each IP-to-MAC binding. The ingress and egress PEs participate in MAC and IP forwarding across the end-to-end service path, but the forwarding responsibilities differ by direction and stage. The false statement is option C. The statement says all MAC-VRFs connected to the L3 EVPN network must exist on each PE, but that is not the correct requirement in this question's verified answer set. In practical EVPN designs, the exact MAC-VRF placement depends on whether the service is implemented as asymmetric, symmetric, interface-less, or interface-ful routing. Here, the course answer marks the universal MAC-VRF requirement as false. Reference: asymmetric L3 EVPN routing, RT-2 MAC/IP advertisements, ARP and MAC forwarding behavior.
NEW QUESTION # 27
Which of the following statements about the configuration of a distributed Layer 2 EVPN in a Nokia SR Linux is FALSE?
- A. The route distinguisher is auto-generated using the autonomous system number and EVI.
- B. Each PE participating in the Layer 2 EVPN must be configured with the same EVPN instance ID (EVI).
- C. The route-targets are manually configured when the leaf routers are in different autonomous systems.
- D. Only one VXLAN-interface can be associated to the Layer 2 EVPN.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
A distributed Layer 2 EVPN in SR Linux is implemented using MAC-VRF network instances, EVPN control-plane signaling, and VXLAN data-plane encapsulation. A common mistake is assuming that every PE must use the same EVI value for the same L2 service. In SR Linux, the important operational requirement is that the correct EVPN routes are imported and exported using matching route-target policy, not necessarily that every PE has the same locally configured EVI. Therefore, option A is false. The route distinguisher can be automatically generated using local values such as the autonomous system number and EVI, giving each PE's EVPN routes uniqueness in MP-BGP. A MAC-VRF is associated with VXLAN encapsulation for its data-plane service mapping, and route targets may need to be manually configured when leaf routers are in different autonomous systems because automatic derivation may not produce matching import/export policy across AS boundaries. The key separation is this: the RD gives uniqueness, the route target controls service membership, and the EVI is a local service identifier rather than a universal mandatory match in all designs. Reference: SR Linux distributed L2 EVPN configuration, EVI, RD auto-generation, route-target policy.
NEW QUESTION # 28
Consider the exhibit.
All IP-VRFs are configured properly and are operational.
Which of the following statements is FALSE?
- A. All connected leaf routers will use an AD per ES update to advertise single-active redundancy.
- B. The elected DF will use the AD per EVI update to identify itself as primary.
- C. Only the elected DF will advertise the customer IP prefix route to the BGP route reflector.
- D. One of the connected leaf routers will be elected DF.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In a single-active EVPN multi-homing design, the connected PE routers perform Designated Forwarder election to determine which PE is active for the relevant service or Ethernet Segment. The DF is responsible for forwarding toward the attached segment and, in a Layer 3 multi-homing case, only the active/DF PE advertises the customer IP prefix route toward the EVPN control plane. Single-active redundancy is communicated using Ethernet Segment-related EVPN procedures, including Ethernet A-D information, so remote PEs can identify the redundancy behavior and avoid forwarding traffic to an inactive attachment. The false statement is that the elected DF uses an AD per EVI update to identify itself as primary. AD per EVI is primarily used to advertise per-service Ethernet Segment reachability and support aliasing/load-balancing behavior in multi-homed services. DF election itself is driven by Ethernet Segment route procedures, not by the DF declaring itself primary through AD per EVI. Therefore, option B misstates the role of AD per EVI in the single-active L3 multi-homing control plane. Reference: EVPN DF election, single-active multi-homing, Ethernet A-D routes.
NEW QUESTION # 29
Consider the exhibit.
Based upon the information in the screen captures, which of the following statements is FALSE?
- A. The IRB interface will snoop all ARP and GARP messages received on IRB sub-interface 100.100.
- B. The ARP cache for ip-vrf 100 is only required to contain host prefixes for the local subnets.
- C. Leaf-1 will not generate any EVPN route-type 5 updates for IP-VRF-100.
- D. Leaf-1 will advertise EVPN route-type 2 updates with host IP and MAC information for MAC-VRF100.
Answer: A
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
The exhibit describes an EVPN IRB environment where MAC-VRF100 and IP-VRF-100 exchange host reachability through local learning and EVPN advertisements. Leaf-1 can advertise EVPN route type 2 updates containing host MAC/IP information for MAC-VRF100. This is the normal mechanism used to distribute endpoint bindings learned from local hosts. If IP-VRF-100 is not configured for prefix advertisement, Leaf-1 will not generate EVPN route type 5 updates for that IP-VRF, so option A is consistent. The ARP cache in the IP-VRF is normally required for local subnet host resolution; remote host reachability can be learned through EVPN rather than requiring every remote ARP entry to be learned by local data-plane ARP. Option B is false because ARP/GARP snooping is not performed by the IRB interface in the manner stated. ARP/GARP learning for proxy ARP and MAC/IP advertisement is associated with the MAC-VRF bridge-domain behavior and the local access side, not with the IRB subinterface indiscriminately snooping all ARP/GARP messages as described. Reference: EVPN IRB operation, RT-2 host MAC/IP advertisement, RT-5 behavior, ARP/GARP learning scope.
NEW QUESTION # 30
Consider the exhibit.
The network is configured for interface-less symmetric routing with an ECMP of 4 enabled on all leaf routers.
Which of the following statements is FALSE?
- A. Anycast gateway is an optional configuration on the Leaf1 and Leaf2 IRB interfaces.
- B. The IRB interfaces on Leaf1 and Leaf2 must be configured to advertise learned local host-routes.
- C. MAC-VRF100 on Leaf1 and Leaf2 must have BGP EVPN and BGP VPN configured.
- D. IP-VRF1 on Leaf1, Leaf2 and Leaf3 must be configured with a VXLAN-routed interface.
Answer: A
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In interface-less symmetric L3 EVPN routing, hosts in a subnet may be attached to different leaf routers, while inter-subnet forwarding is performed through the IP-VRF using VXLAN routed interfaces. The ingress and egress PEs both participate in L3 forwarding, and the routed VXLAN interface provides the per-IP-VRF overlay data-plane construct needed for symmetric routing. The IRB interfaces on the local MAC-VRFs must advertise learned local host routes so that remote PEs have the necessary host reachability information. The MAC-VRFs also need the appropriate EVPN control-plane configuration so host MAC/IP information can be exchanged, while the IP-VRF participates in L3 VPN-style route exchange for routed reachability. Option A is false because anycast gateway is not optional in this design for Leaf1 and Leaf2. Anycast gateway allows the same default-gateway IP and virtual MAC behavior to exist consistently on multiple leaves serving the same subnet. Without it, host default-gateway behavior would be inconsistent and traffic mobility across the fabric would break expected distributed gateway operation. Reference: interface-less symmetric routing, IRB, anycast gateway, routed VXLAN interface.
NEW QUESTION # 31
Which of the following is always found in an extended community associated with an EVPN update?
- A. The EVPN route type
- B. The VXLAN network ID
- C. The route target
- D. The AFI/SAFI
Answer: C
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
The route target is the extended community consistently associated with EVPN updates to control route import and export between EVPN instances. In SR Linux EVPN services, route targets determine which MAC-VRF or IP-VRF should import a received EVPN route. This is essential for tenant separation because multiple tenants may use overlapping MAC or IP address spaces while sharing the same physical fabric and BGP control plane. The AFI/SAFI is not an extended community; it identifies the BGP address family and subsequent address family used to carry EVPN NLRI. The EVPN route type is also not an extended community; it is part of the EVPN NLRI structure and identifies whether the route is RT-1, RT-2, RT-3, RT-4, RT-5, and so on. The VXLAN network ID may be carried or inferred through service and encapsulation-specific attributes, but it is not universally present as the required extended community in every EVPN update. The route target is the mandatory policy element that enables receiving PEs to place EVPN routes into the correct service context. Reference: EVPN extended communities, route-target import/export policy, tenant service identification.
NEW QUESTION # 32
When providing L3 multi-homing on two or more leaf routers, which of the following is FALSE?
- A. The Ethernet segment is associated with the next-hop for the 3rd party prefixes.
- B. All learned 3rd party prefixes are advertised using EVPN route type 5.
- C. In a single-active multi-homing scenario, the DF-election is used to identify the active leaf router.
- D. In an all-active multi-homing scenario, the DF-election is used to identify the leaf router that is responsible for forwarding BUM traffic to the host.
Answer: D
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
Layer 3 multi-homing is fundamentally about redundant or load-balanced L3 reachability for external prefixes, not about Layer 2 broadcast-domain flooding toward a host. In single-active L3 multi-homing, DF election determines which attached leaf is active for the Ethernet Segment, and only that leaf advertises or forwards for the attached customer route as required by the redundancy model. In all-active L3 multi-homing, multiple leaf routers can be valid next-hops for the same learned third-party prefix, and remote PEs may load-balance toward them based on the Ethernet Segment association. Learned external prefixes are carried as EVPN route type 5 IP Prefix routes, which is the correct route type for L3 reachability. The Ethernet Segment is associated with the next-hop for those prefixes so that remote PEs understand the multi-homed nature of the path. Option B is false because BUM forwarding is a Layer 2 EVPN concern. In an all-active L3 multi-homing scenario, DF election is not used to identify a BUM-forwarding leaf for host traffic in the same way it is used in Layer 2 multi-homing services. Reference: L3 EVPN multi-homing, RT-5 prefix routes, ES next-hop behavior.
NEW QUESTION # 33
Consider the exhibit.
All IP-VRFs are configured properly and are operational.
Which of the following statements is FALSE?
- A. The AD per EVI update will be used to identify which connected leaf is primary.
- B. One of the leaf routers will be elected DF.
- C. All traffic destined to 40.40.40.0/24 will be forwarded through Leaf3 due to the BGP connection to the CE VNF.
- D. All connected leaf routers will use single active redundancy.
Answer: D
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
The scenario describes Layer 3 EVPN multi-homing with an IP-VRF service and an external CE VNF advertising the 40.40.40.0/24 prefix through BGP. A DF election can occur among the leaf routers participating in the Ethernet Segment, and the active/primary forwarding node is used for the relevant service behavior. The AD per EVI route can participate in identifying service-level reachability for the Ethernet Segment, and the prefix traffic follows the valid advertised path toward the CE VNF. Because Leaf3 has the BGP connection to the CE VNF, traffic for 40.40.40.0/24 is forwarded through Leaf3. Option B is false because it incorrectly states that all connected leaf routers will use single-active redundancy. The exhibit and answer context indicate a more specific forwarding/primary selection for the service, not a blanket statement that every connected leaf operates using single-active redundancy. In L3 multi-homing, redundancy behavior depends on the ES mode, prefix advertisement, next-hop association, and CE connectivity. The forwarding decision for the customer prefix is tied to the active/valid route advertisement, not to every leaf uniformly acting as single-active. Reference: L3 EVPN multi-homing, DF election, AD per EVI role, PE-CE BGP prefix forwarding.
NEW QUESTION # 34
Consider the exhibit.
Leaf1 and Leaf2 have the Ethernet segment configured to use the default election algorithm while Leaf3 and Leaf4 are configured to use the preference-based algorithm with Leaf3 having the higher preference value. The DF candidate list is the same on all leaf routers.
Which of the following leafs is the DF for mac-vrf103?
- A. Leaf4
- B. Leaf2
- C. Leaf1
- D. Leaf3
Answer: D
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
Designated Forwarder election determines which PE forwards BUM traffic from the EVPN overlay toward a multi-homed Ethernet Segment for a given service. In this scenario, all leaf routers share the same DF candidate list for mac-vrf103, but the election configuration is not identical. Leaf1 and Leaf2 use the default algorithm, while Leaf3 and Leaf4 use the preference-based algorithm. Under preference-based DF election, the candidate with the highest configured preference is selected over lower-preference candidates, assuming the candidate list is valid and consistent. The question states that Leaf3 has the higher preference value compared with Leaf4. Therefore, Leaf3 becomes the DF for mac-vrf103. This is the correct outcome because the preference-based election explicitly overrides simple default behavior by assigning operator-defined priority to a PE. In production designs, this is useful when the operator wants deterministic forwarding placement, maintenance control, or service-specific primary-path selection rather than relying only on the default modulo-based DF selection process. Reference: EVPN DF election, preference-based algorithm, MAC-VRF service forwarding.
NEW QUESTION # 35
Which of the following statements about the gateway-less data center interconnect solution is FALSE?
- A. The IP addresses of the leaf routers need to be re-distributed into the WAN.
- B. The leaf routers are able to establish a full mesh of VXLAN tunnels across the WAN.
- C. The EVPN overlay is transparently carried over the WAN network.
- D. The data center gateway routers maintain a MP-BGP EVPN peering with the data center route reflector.
Answer: D
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In a gateway-less DCI design, there is no dedicated gateway device performing EVPN-to-WAN service interworking. Instead, the data center EVPN overlay is extended across the WAN more directly. Because leaf routers must establish overlay reachability across sites, the IP addresses of the leaf VTEPs need to be reachable through the WAN, commonly by redistributing or otherwise carrying the necessary loopback reachability. The WAN transparently carries the EVPN/VXLAN overlay, and leaf routers can establish VXLAN tunnels across the WAN to remote leaves. Option D is false because it introduces "data center gateway routers" maintaining MP-BGP EVPN peering with the data center route reflector. That is not the gateway-less model; it describes a gateway-based role that does not exist as a separate function in this architecture. In gateway-less DCI, the EVPN control-plane and VXLAN data-plane extension are handled by the fabric endpoints themselves, so the design trades demarcation and interworking control for a more direct overlay extension model. Reference: gateway-less DCI, WAN reachability for leaf VTEPs, transparent EVPN overlay carriage, VXLAN tunnel extension.
NEW QUESTION # 36
Consider the exhibit.
Which of the following statements is FALSE?
- A. The MAC address associated to the vxlan-interface will not age out.
- B. The MAC address 00:00:00:00:00:01 was learned through the data plane.
- C. The remote host's IP address is 100.0.2.3.
- D. The VXLAN network identifier configured for this MAC-VRF is 100.
Answer: A
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In an SR Linux Layer 2 EVPN MAC-VRF, locally attached MAC addresses are learned through the data plane on local access interfaces, while remote MAC addresses are learned from MP-BGP EVPN control-plane advertisements and installed with a VXLAN next-hop. The exhibit shows one local learned MAC on an Ethernet subinterface and another MAC learned through EVPN with a VXLAN interface and VNI 100. The remote VTEP or next-hop information identifies the remote endpoint, and the VNI maps the received VXLAN traffic to the correct MAC-VRF service. The false statement is C because saying that the MAC address associated with the vxlan-interface "will not age out" is too absolute. A remote EVPN MAC is not aged in the same way as a local data-plane-learned MAC, but it can still be removed when the corresponding EVPN route is withdrawn, invalidated, or no longer present in the control plane. The "N/A" style aging behavior does not mean permanent retention. Reference: SR Linux MAC-VRF verification, local MAC learning, EVPN-learned remote MACs, VXLAN VNI mapping.
NEW QUESTION # 37
Which of the following statements about utilizing VXLAN for the data plane in the data center is FALSE?
- A. It has the capability to isolate up to 16 million different overlays.
- B. VXLAN was developed to support EVPN networks in the data center.
- C. It may use ECMP to provide efficient utilization of the underlay interfaces within the data center.
- D. It allows the creation of a Layer 2 overlay network that can span the entire data center.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
VXLAN provides a Layer 2 overlay over a Layer 3 underlay by encapsulating Ethernet frames in UDP/IP. This allows tenant bridge domains to span a routed IP fabric without requiring the underlay itself to behave like one large Layer 2 network. VXLAN uses a 24-bit VXLAN Network Identifier, which supports approximately 16 million logical overlays, far exceeding the scale of traditional 12-bit VLAN IDs. Because the VXLAN underlay is IP-routed, traffic can benefit from ECMP across equal-cost paths, improving fabric utilization and resiliency. The false statement is B. VXLAN was not originally developed specifically to support EVPN. VXLAN began as a data-plane overlay encapsulation technology, while EVPN later became the preferred control plane for distributing MAC, MAC/IP, multicast, and prefix reachability in VXLAN-based fabrics. In modern data center design, EVPN and VXLAN are commonly paired: VXLAN supplies the encapsulation and VNI-based segmentation, while EVPN supplies scalable control-plane learning and signaling. Reference: VXLAN data plane, EVPN control plane, ECMP underlay, VNI-based tenant isolation.
NEW QUESTION # 38
Consider the exhibit.
Which of the following statements about the configuration and operation of this setup is FALSE?
- A. The host will forward all BUM traffic toward the DF.
- B. The MAC-VRF on Leaf3 will need to be configured with ECMP to be able to load balance between Leaf1 and Leaf2.
- C. A sub-interface of lag1 is associated to the MAC-VRF on Leaf1 and Leaf2.
- D. The Ethernet segment ES-1 is configured with multi-homing-mode all-active.
Answer: A
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
This scenario describes all-active Layer 2 EVPN multi-homing with a host connected through a LAG to Leaf1 and Leaf2. The LAG subinterface is associated with the MAC-VRF on both participating leaves, and the Ethernet Segment ES-1 is configured for all-active multi-homing. In all-active operation, both leaf routers can be active attachment points for host-originated traffic, and remote traffic can use EVPN multi-homing mechanisms to reach the segment. Option D is false because the host does not know or use the EVPN Designated Forwarder state when sending BUM traffic. The host forwards over its LAG based on its local LAG hashing and LACP behavior. DF election is an EVPN PE-side mechanism used mainly to control which PE forwards BUM traffic from the EVPN overlay toward the Ethernet Segment, preventing duplicate delivery to the multihomed access network. The host itself does not selectively forward all BUM traffic toward the DF. That distinction is critical: DF controls overlay-to-segment replication, while the host's LAG controls host-to-leaf link selection. Reference: all-active L2 EVPN multi-homing, host LAG behavior, DF election scope, BUM forwarding.
NEW QUESTION # 39
Consider the exhibit.
The network is going to be designed to use interface-less symmetric routing.
Which of the following statements is TRUE?
- A. The IRB configuration does not require anycast gateway configuration on the ip-vrf.
- B. Forwarding information will be exchanged between the PEs using EVPN route-type 2 updates.
- C. An instance of each mac-vrf is required on each leaf.
- D. The ingress PE will perform layer 2 and layer 3 lookups while the egress PE will perform layer 2 lookup.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In interface-less symmetric routing, the EVPN fabric exchanges host forwarding information using EVPN route type 2 MAC/IP advertisements. RT-2 carries the host MAC address and, when present, the associated host IP address, allowing remote PEs to build the forwarding state needed for distributed gateway operation. Unlike asymmetric routing, interface-less symmetric routing does not require every MAC-VRF to be instantiated on every PE. The design scales better because each leaf only needs the locally attached MAC-VRFs plus the shared IP-VRF/routed VXLAN construct for inter-subnet forwarding. Option B describes an asymmetric forwarding pattern more than a symmetric one; in symmetric routing, both ingress and egress PEs perform routed forwarding functions through the IP-VRF. Option C is also incorrect because anycast gateway is fundamental when multiple leaves provide the same default-gateway service for a subnet. Therefore, the true statement is that forwarding information is exchanged using EVPN route type 2 updates. Reference: interface-less symmetric routing, EVPN RT-2 host MAC/IP signaling, distributed IRB operation.
NEW QUESTION # 40
When PEs are connected to an Ethernet segment with at least one active MAC-VRF, which of the following statements about the AD per EVI updates sent by a PE is FALSE?
- A. A PE will advertise one AD per EVI update for each MAC-VRF associated to the Ethernet segment.
- B. It contains the multi-homing type used for the Ethernet segment.
- C. It contains the VNI information that is to be used in the data plane.
- D. It contains the route-target so that the update can be imported into the correct MAC-VRF instance.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
Ethernet Auto-Discovery per EVI routes are EVPN route type 1 advertisements used in multi-homing at the service-instance level. A PE sends an AD per EVI route for each MAC-VRF associated with the Ethernet Segment. These routes allow remote PEs to understand that the advertising PE has reachability to a given EVI through the shared ES. They are also used for aliasing and fast convergence, because a remote PE can treat multiple attached PEs as valid paths for traffic toward the same multihomed segment. In VXLAN EVPN, the update can include data-plane information such as the VNI, and it carries route-target information so the route is imported into the correct MAC-VRF. Option B is false because the multi-homing type or redundancy mode is not carried in the AD per EVI update as stated. Redundancy behavior is associated with Ethernet Segment-level signaling and configuration, especially ES discovery and related route attributes, not with AD per EVI as the mechanism that declares the multi-homing type. Reference: EVPN RT-1 AD per EVI, MAC-VRF association, route target, VNI, aliasing.
NEW QUESTION # 41
Leaf routers are configured to support Layer 2 multi-homing all-active mode.
Which of the following statements is FALSE?
- A. The 2nd through 7th octets of the ESI must not be all zeros.
- B. The multi-homing mode of all-active must be configured for the Ethernet segment.
- C. The Ethernet segment must be administratively enabled.
- D. All of the sub-interfaces of the LAG must be configured in the Ethernet segment.
Answer: A
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
For Layer 2 all-active EVPN multi-homing on SR Linux, the Ethernet Segment configuration is the control-plane anchor that binds the redundant access attachment to EVPN. The relevant LAG subinterfaces must be associated with the Ethernet Segment so that the PE can advertise the segment correctly and apply split-horizon and aliasing behavior. The Ethernet Segment must also be administratively enabled; otherwise, the PE will not participate properly in ES discovery and DF procedures. The multi-homing mode must be set to all-active to permit forwarding through multiple attached leaf routers and support host-side LAG operation. The false statement is option B. The Ethernet Segment Identifier has a defined structure, and the blanket statement that the 2nd through 7th octets "must not be all zeros" is not a valid requirement as stated. What matters operationally is that the ESI uniquely identifies the same multi-homed Ethernet Segment across participating PEs and is consistently configured where required. The ESI must be non-zero as a meaningful segment identifier, but the specific octet restriction in the option is not the SR Linux all-active configuration rule. Reference: SR Linux L2 EVPN all-active multi-homing, Ethernet Segment configuration, LAG association.
NEW QUESTION # 42
When PEs are connected to an Ethernet segment with at least one active MAC-VRF, which of the following statements about the AD per EVI updates sent by a PE is FALSE?
- A. It is used by the remote peers for aliasing.
- B. It contains the route-target so that the update can be imported into the correct MAC-VRF instance.
- C. It advertises the multi-homing mode used by the PEs for the Ethernet segment.
- D. It contains the VNI that is to be used by the remote peers in the data plane.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
Ethernet Auto-Discovery per EVI information is used in EVPN multi-homing to advertise that a PE has reachability to a particular Ethernet Segment for a specific EVPN instance. Remote PEs use this information for aliasing, allowing them to forward known unicast traffic toward a multi-homed Ethernet Segment through eligible PEs rather than relying only on the PE that advertised a specific MAC route. In VXLAN-based EVPN, the update also carries information needed by remote peers to select the proper data-plane encapsulation and VNI for the service. The multi-homing behavior advertised with the Ethernet Segment enables remote peers to understand whether the attachment is operating in all-active or single-active mode. Option D is the false statement in this context because route-target handling is a general BGP EVPN import/export mechanism associated with VPN route policy and extended communities; it is not the specific operational function that defines AD per EVI behavior. The AD per EVI route's purpose is Ethernet Segment reachability for an EVI, not route-target-based service identification by itself. Reference: EVPN route type 1, AD per EVI, aliasing and multi-homing signaling.
NEW QUESTION # 43
Consider the exhibit.
Host-2 is sending data to Host-1. The network is designed to use asymmetric routing.
Which of the following statements about the operation of the data plane is TRUE?
- A. Leaf-1 forwards the data for mac-vrf-2 towards Leaf-2 with a VNI of 2.
- B. Leaf-2 does a MAC look-up using mac-vrf-1 and forwards the data towards Host-1.
- C. Leaf-2 IP-VRF consults the ARP table to learn Host-1 MAC address.
- D. Leaf-2 forwards the data for mac-vrf-2 towards the IP-VRF using its IRB interface.
Answer: B
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In asymmetric EVPN IRB, the ingress PE performs routing from the source subnet into the destination subnet, then forwards the packet across the VXLAN overlay using the destination MAC-VRF/VNI. The egress PE does not perform another IP-VRF lookup for that packet; it performs Layer 2 forwarding in the destination MAC-VRF. In this scenario, Host-2 sends traffic toward Host-1. After the ingress routing decision, the traffic arrives at Leaf-2 in the context of the destination MAC-VRF, mac-vrf-1. Leaf-2 then performs a MAC lookup in mac-vrf-1 and forwards the frame to Host-1. Option D is therefore correct. Option A reverses the forwarding direction and misidentifies the leaf action. Option B incorrectly sends mac-vrf-2 traffic toward the IP-VRF on Leaf-2, even though Leaf-2 is acting as the egress PE for Host-1. Option C is also incorrect because the egress forwarding action is based on the MAC table in the destination MAC-VRF, not an IP-VRF ARP lookup at that stage. Reference: asymmetric L3 EVPN IRB data-plane operation, ingress routing and egress MAC forwarding.
NEW QUESTION # 44
A host is connected to a MAC-VRF on leaf1 and leaf2. The MAC-VRF interfaces on leaf1 and leaf2 are associated to an Ethernet segment configured for active-standby multi-homing.
Which of the following statements is FALSE?
- A. The non-DF is capable of forwarding unicast traffic from the remote PEs to the host.
- B. The DF will forward all BUM traffic from the remote PEs to the host.
- C. Leaf1 and leaf2 will hold an election to identify which leaf router will be the DF for the MAC-VRF.
- D. Only the DF will accept traffic from the host.
Answer: A
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In active-standby, or single-active, Layer 2 EVPN multi-homing, only one PE is active for the Ethernet Segment and MAC-VRF at a time. Leaf1 and Leaf2 participate in DF election, and the elected DF becomes the active forwarding PE for that service attachment. Because this is not all-active multi-homing, the non-DF must not forward traffic to the host for the protected service. This prevents duplicate frames, incorrect MAC learning, and loops on the access side. The DF accepts traffic from the host and forwards BUM traffic received from remote PEs toward the host-facing segment. Option D is false because it claims that the non-DF can forward unicast traffic from remote PEs to the host. In single-active operation, remote peers must direct traffic to the active PE, and the standby PE remains ready to take over only after DF state changes. This is the operational distinction from all-active multi-homing, where more than one PE may be used for forwarding depending on the traffic type and aliasing behavior. Reference: single-active L2 EVPN multi-homing, DF role, non-DF forwarding suppression.
NEW QUESTION # 45
Leaf routers are configured to support Layer 2 multi-homing all-active mode.
Which of the following statements is FALSE?
- A. If using LACP, the system-id-mac must uniquely identify each leaf router connected to the host.
- B. If VLAN tagging is to be used, then it must be enabled on the LAG interface.
- C. The LAG interface must then be associated with the Ethernet segment.
- D. A LAG must be configured on the participating leaf routers.
Answer: A
Explanation:
Comprehensive and Detailed 150 to 250 words of Explanation From [SR Linux EVPN and Data Center Interconnect/Course Guide/topics]:
In all-active Layer 2 EVPN multi-homing, the host is typically dual-homed to two or more leaf routers using a LAG. The participating leaf routers must configure the LAG and associate it with the Ethernet Segment so EVPN can advertise the common ESI and apply aliasing, split-horizon, and DF procedures. If VLAN tagging is used for service separation, tagging must be configured on the LAG interface so that the correct subinterfaces can bind into the MAC-VRF and Ethernet Segment. Option C is false because it states that the LACP system-id-mac must uniquely identify each leaf router. In an all-active EVPN multihomed LAG, the opposite principle applies: from the host's LACP perspective, the multihomed leaf pair must appear as a single logical LACP system. That generally requires a shared LACP system ID or coordinated system MAC behavior across the participating PEs. If each leaf presented a unique LACP system identity, the host would treat them as separate LAG partners and the all-active bundle would not form correctly. Reference: all-active L2 EVPN multi-homing, LAG attachment, LACP system ID behavior, Ethernet Segment association.
NEW QUESTION # 46
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