VXLAN

JNCIP-DC · 50 questions

• City architects ask how VTEPs can learn remote MAC and IP mappings for municipal workloads without relying on endless unknown-unicast flooding. Which control-plane approach best answers that design goal?
• A township still runs an underlay multicast group for VXLAN BUM delivery between civic VTEPs. What role does that multicast underlay play in a classic VXLAN design?
• A municipal standard mandates EVPN for VXLAN signaling across the city’s leaf-spine pods. Which statement correctly identifies that control plane?
• Ops confuses a VXLAN VNI with the local VLAN ID while reading control-plane advertisements on a county leaf. What is the correct distinction?
• A county enables VXLAN between leaves but deploys no EVPN or other MAC/IP control plane. What is the primary remote-learning implication?
• The civic NOC asks what head-end replication means for VXLAN BUM when the underlay has no multicast. Which explanation is accurate?
• City architects want to know which protocol carries EVPN routes for the municipal VXLAN fabric. Which answer is correct?
• A lab mixes statically configured VXLAN tunnels with EVPN-driven dynamic VTEP discovery for the same civic VNI. What control-plane contrast should engineers keep clear?
• A public-safety fabric team asks whether underlay PIM is still required if the pod uses EVPN-VXLAN with ingress replication for BUM. What is the sound conclusion?
• Engineers debate why ingress replication lists on municipal leaves grow as more VTEPs join each VNI. What scaling relationship should they cite?
• A metro design assigns different VNIs to Parks, Utilities, and Public Safety departments. How should architects treat those VNIs in the VXLAN control plane?
• Ops sees EVPN Type-2 MAC/IP routes on a city leaf but still claims the VXLAN MAC control plane is OSPF. Which correction is accurate?
• During a city DR test, BGP EVPN sessions flap while some existing VXLAN data-plane flows briefly continue. What operational nuance is most accurate at concept level?
• A municipal leaf advertises EVPN routes for a VNI, but peer leaves have no matching route-target import. What is the likely learning result?
• Township engineers ask what an L2 VNI versus an L3 VNI means in an EVPN-VXLAN control plane. Which distinction is correct?
• Municipal IPv6 tenants need host advertisements in the EVPN-VXLAN control plane alongside IPv4. What design awareness is required?
• The NOC wants multicast optimization inside an EVPN-VXLAN civic fabric rather than pure unoptimized flooding. What high-level control-plane expectation is fair?
• A design review asks who the “controller” is in a controllerless EVPN-VXLAN municipal fabric. Which answer best reflects the architecture?
• The city enables VXLAN on access devices that cannot speak EVPN while the leaf standard expects EVPN signaling. What problem does that create?
• After a route-target change on a county MAC-VRF, remote MACs withdraw from several leaves. What control-plane membership effect explains that?
• A packet between two VMs on different municipal leaves must cross the VXLAN fabric. What data-plane behavior is fundamental?
• City firewall and capture standards ask which UDP destination port identifies VXLAN traffic in the data plane. Which value is correct?
• Ops notices outer IP headers between civic leaves use loopback addresses as tunnel endpoints. What do those addresses represent in the VXLAN data plane?
• A township wonders what happens to the access VLAN tag when a frame crosses the VXLAN fabric between leaves. Which data-plane statement is correct?
• After enabling VXLAN on the municipal fabric, operators see MTU blackholes for large tenant frames. What data-plane planning issue is most likely?
• A municipal NOC captures leaf-to-spine fabric packets and sees a VNI field inside the VXLAN header. What data-plane role does that VNI play on the egress VTEP?
• Two servers attached to different city leaf VTEPs share the same subnet and VNI. How should east-west traffic between them behave in the VXLAN data plane?
• A county EVPN-VXLAN fabric must move traffic between two different tenant subnets on different VNIs. Which data-plane path concept applies?
• A transit-agency leaf receives a VXLAN packet destined to a server on a local access port. What should the VTEP do in the data plane?
• City operators enable VXLAN on two leaves, but the underlay cannot reach the remote VTEP loopback. What happens to the overlay data plane?
• A library data-center leaf-spine fabric load-balances VXLAN traffic across multiple underlay uplinks. What does underlay ECMP primarily hash on for those encapsulated flows?
• A public-works fabric must deliver broadcast, unknown unicast, and multicast (BUM) frames to other VTEPs in a VNI. What data-plane behavior is required?
• A county security team inserts an underlay firewall that drops UDP destination port 4789 between leaves and spines. What class of failure should operators expect?
• Two municipal tenant hosts are mapped to the same VNI number on different leaves, but each leaf mistakenly binds that VNI into a different VRF. What is the data-plane consequence?
• Telemetry on a city leaf-spine path shows the outer IP TTL of VXLAN packets decrementing at each underlay hop. What does that indicate about the data plane?
• A city security board asks whether enabling VXLAN by itself encrypts tenant traffic across the fabric. What is the accurate data-plane security statement?
• A server in the parks department sends jumbo frames that fit the access MTU but exceed what the underlay can carry once VXLAN headers are added. What planning issue does this expose?
• Municipal operators see DF-bit related drops and fragmentation symptoms for VXLAN-encapsulated traffic. What is the preferred data-plane approach?
• A dual-homed application pair at the water utility uses ESI multihoming with anycast VTEP behavior. At a high level, what does that change in the VXLAN data plane?
• A county engineer must describe the end-to-end VXLAN data-plane path for a unicast frame between servers on different leaves. Which sequence is correct?
• An engineer must verify that a VLAN used by court-records servers is mapped into the correct VXLAN VNI on a Junos leaf. What should they confirm?
• The municipal NOC needs to confirm a leaf can source and reach VXLAN traffic as a VTEP. Which verification focus is most appropriate?
• City monitoring shows a leaf encapsulating frames, yet the remote host MAC never appears and traffic fails. How should troubleshooting be split?
• Show commands on a township leaf reveal missing VXLAN tunnels or overlay next-hops toward a remote VTEP. What should operators conclude about monitoring?
• A vendor VTEP in a shared civic colo uses a nonstandard UDP port while the city’s Juniper leaves expect standard VXLAN port 4789. What is the likely result?
• Ops incorrectly associates VXLAN with an IRB on a municipal leaf and routed tenant traffic breaks. What configuration caution applies?
• Two hosts on the same city leaf communicate, but the same subnet fails to a host on a remote leaf. Where should VXLAN troubleshooting focus first?
• Counters on a source leaf show VXLAN packets leaving, but the remote leaf shows no corresponding VXLAN ingress or decap. What troubleshooting approach helps?
• A change window adds a new VNI on a municipal leaf but omits flood-list or EVPN membership for that VNI. What incomplete-enablement failure should be expected?
• A municipal VXLAN runbook needs a sensible first-pass order when overlay traffic fails between leaves. Which sequence best structures troubleshooting?