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Extreme Fabric (Fabric Connect) study materials
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Extreme Fabric (Fabric Connect) practice questions

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Question 1Fabric design and deployment

In Extreme Fabric Connect, which component is responsible for maintaining the network topology database and computing shortest paths across the SPB backbone?

  1. The Backbone Edge Bridge (BEB)
  2. The Backbone Core Bridge (BCB) Correct answer.
  3. The management appliance
  4. The access-layer edge switch

Explanation

BCBs sit in the SPB core and run the IS-IS link-state instance that builds the topology database and computes shortest-path trees. BEBs attach services at the edge and do not perform the core path computation role.

Question 2Fabric design and deployment

Which identifier uniquely names a service instance in an Extreme Fabric Connect network so that it can be extended across BEBs?

  1. The OSPF area ID
  2. The I-SID Correct answer.
  3. The port MAC address
  4. The VLAN ID

Explanation

An I-SID (Backbone Service Instance Identifier) identifies a service instance in the SPB fabric and is used to stretch that service between BEBs. VLAN IDs are local to a BEB and are mapped to the I-SID.

Question 3Fabric design and deployment

What is the primary purpose of the Extreme Fabric Connect Shortest Path Bridging control protocol running on backbone links?

  1. To distribute link-state information and build a loop-free, equal-cost multipath topology Correct answer.
  2. To translate VLAN tags between access and trunk ports
  3. To assign DHCP leases to endpoints attached to edge ports
  4. To authenticate users against a RADIUS server

Explanation

SPB uses an IS-IS link-state instance to advertise node and link information, producing a loop-free topology with equal-cost multipath forwarding. The other listed functions belong to separate features such as DHCP, authentication, or VLAN handling.

Question 4Fabric design and deployment

A designer wants a BEB to advertise an IP subnet into the fabric so remote BEBs can reach it without running a routing protocol on the access side. Which Fabric Connect feature should be used?

  1. LACP
  2. SPBM multicast
  3. IP Shortcut Routing Correct answer.
  4. Fabric Attach

Explanation

IP Shortcut Routing lets an edge device inject IP subnet information into the fabric so other edge devices can reach it directly over the SPB backbone. This avoids needing a separate routing protocol on the access side.

Question 5Fabric design and deployment

Which Fabric Connect capability allows a non-fabric-aware access switch or endpoint to be automatically provisioned onto the fabric with minimal manual configuration?

  1. IP Shortcut Routing
  2. VRF leaking
  3. SPB multicast
  4. Fabric Attach Correct answer.

Explanation

Fabric Attach uses auto-sensing to detect and provision non-fabric devices, extending fabric services to the access edge with minimal manual configuration. It is distinct from routing and multicast features.

Question 6Fabric design and deployment

A network engineer is deploying a two-tier Fabric Connect design and wants redundant BCBs so that loss of one core node does not isolate edge services. Which design principle best supports this?

  1. Interconnect BCBs with at least two equal-cost paths so SPB can use multipath forwarding Correct answer.
  2. Disable IS-IS on redundant links to avoid loops
  3. Attach all BEBs to a single BCB to simplify the topology
  4. Place all BEBs in the same VLAN as the BCBs

Explanation

SPB supports equal-cost multipath, so providing at least two diverse paths between BCBs lets traffic reconverge if one core node or link fails. Single-homing BEBs or disabling IS-IS removes the redundancy the design needs.

Question 7Fabric design and deployment

Which statement best describes how a BEB maps a local VLAN to a fabric service?

  1. The VLAN is associated with an I-SID on the BEB, and the I-SID carries the service across the backbone Correct answer.
  2. The VLAN ID is copied unchanged to every BCB in the core
  3. The VLAN is translated to an OSPF area before entering the fabric
  4. The VLAN is replaced by the BEB's management IP address

Explanation

Service mapping on a BEB binds an access VLAN to an I-SID, and the I-SID is what traverses the SPB backbone. VLAN IDs remain locally significant and are not carried unchanged across the core.

Question 8Fabric design and deployment

An administrator needs to verify that a newly configured I-SID is active on a BEB. Which action most directly confirms the service state?

  1. Ping the BCB loopback address
  2. Inspect the DHCP snooping bindings
  3. Check the I-SID status in the fabric service table on the BEB Correct answer.
  4. Review the LACP neighbor table

Explanation

The fabric service or I-SID table on the BEB reports whether the service instance is active and which interfaces participate. Pinging a loopback or checking LACP/DHCP tables tests unrelated functions.

Question 9Fabric design and deployment

Which benefit is most characteristic of deploying Fabric Connect compared with a traditional spanning-tree access and aggregation design?

  1. All links can forward using shortest-path multipath instead of blocking redundant links Correct answer.
  2. VLANs can no longer be used on edge ports
  3. Every switch must run OSPF to forward traffic
  4. Broadcast domains are eliminated entirely at layer two

Explanation

SPB uses a link-state topology with equal-cost multipath, so redundant links forward traffic instead of being blocked as in spanning tree. It does not require OSPF on every switch, nor does it remove VLAN support at the edge.

Question 10Fabric design and deployment

What does the term 'Backbone Edge Bridge' specifically indicate about a device in an Extreme Fabric Connect deployment?

  1. It connects access or service interfaces to the SPB backbone and performs service encapsulation Correct answer.
  2. It only forwards traffic within the core without any service interfaces
  3. It provides out-of-band management access to the fabric
  4. It acts as a DHCP relay for the entire fabric

Explanation

A BEB sits at the boundary between the SPB backbone and service or access interfaces, encapsulating and decapsulating services. Core-only forwarding is the BCB role, and management or DHCP functions are separate.

Question 11Fabric design and deployment

A designer wants to isolate tenant traffic so that each tenant has its own routing table while sharing the same physical Fabric Connect infrastructure. Which approach fits best?

  1. Create separate VRFs and map each tenant's services to distinct I-SIDs Correct answer.
  2. Assign all tenants to one VRF and rely on VLAN separation
  3. Disable IP Shortcut Routing for all tenants
  4. Use a single I-SID for all tenants with different QoS markings

Explanation

VRFs provide separate routing tables on the edge devices, and distinct I-SIDs keep each tenant's layer-two services isolated across the backbone. Sharing one VRF or one I-SID would not provide routing or service isolation.

Question 12Fabric design and deployment

Which protocol does the SPB control plane in Extreme Fabric Connect use to exchange topology information between backbone nodes?

  1. STP
  2. RIP
  3. BGP
  4. IS-IS Correct answer.

Explanation

SPB relies on an IS-IS link-state instance to distribute topology information among backbone nodes. BGP, RIP, and STP serve different purposes and are not the SPB control protocol.

Question 13Fabric design and deployment

An engineer observes that traffic between two BEBs follows a longer path than expected even though a shorter path exists in the core. Which design factor most likely explains this in an SPB fabric?

  1. The management VLAN is untagged
  2. The I-SID is not enabled on the intermediate BEBs needed for the shorter path Correct answer.
  3. The access ports are configured as LACP bundles
  4. The DHCP server is misconfigured on the edge

Explanation

SPB forwards a service only across nodes where the relevant I-SID is enabled, so a shorter physical path may be unusable if intermediate BEBs lack that I-SID. DHCP, LACP, and management VLAN settings do not determine service path selection.

Question 14Fabric design and deployment

Which statement accurately describes the relationship between a BCB and a BEB in a typical Fabric Connect topology?

  1. BCBs and BEBs must always be the same physical device
  2. BCBs terminate all tenant services while BEBs only forward core traffic
  3. BEBs form the core while BCBs attach endpoints
  4. BCBs form the core transport while BEBs provide service attachment at the edge Correct answer.

Explanation

In SPB terminology, BCBs provide the backbone transport and BEBs attach services at the edge of the fabric. The roles are distinct, although a platform may support both functions.

Question 15Fabric design and deployment

A network team wants to extend a layer-two service between two data centers over a routed SPB backbone. What must be consistent on both BEBs for the service to work?

  1. The same VLAN ID must be used on all core links
  2. The same OSPF process ID must be configured
  3. The same management IP subnet must be assigned
  4. The same I-SID must be configured for the service on both BEBs Correct answer.

Explanation

The I-SID is the fabric-wide service identifier, so both BEBs must use the same I-SID to join the same service instance. Local VLAN IDs can differ, and OSPF or management addressing are unrelated to service extension.

Question 16Fabric design and deployment

Which outcome is a direct result of enabling IP Shortcut Routing on a BEB?

  1. Remote BEBs learn the advertised IP subnet and can forward to it over the SPB backbone Correct answer.
  2. The BEB stops participating in the IS-IS topology
  3. Access ports are converted to routed ports automatically
  4. All layer-two I-SIDs on the BEB are automatically deleted

Explanation

IP Shortcut Routing injects IP prefix information into the fabric so other BEBs can reach that subnet directly across the SPB backbone. It does not delete I-SIDs, remove the node from IS-IS, or convert ports automatically.

Question 17Fabric design and deployment

When planning a Fabric Connect deployment, why is it important to define a consistent I-SID numbering scheme across all BEBs?

  1. I-SIDs are used only for management access control
  2. I-SIDs are fabric-wide service identifiers, so conflicting assignments would merge or misdirect services Correct answer.
  3. I-SIDs must match the VLAN ID on every access port
  4. I-SIDs are only locally significant and need no coordination

Explanation

Because an I-SID identifies a service instance across the fabric, a consistent scheme prevents two different services from accidentally sharing an identifier and becoming merged. I-SIDs are not tied to matching VLAN IDs or to management access.

Question 18Fabric design and deployment

Which design choice best reduces the blast radius of a misconfigured I-SID in a large Fabric Connect fabric?

  1. Standardize I-SID allocation with a documented plan and validate services before wide rollout Correct answer.
  2. Disable IS-IS authentication on the backbone
  3. Use random I-SID values for each new service
  4. Enable all I-SIDs on every BEB by default

Explanation

A documented allocation plan and staged validation limit the impact of a misconfigured service identifier. Enabling every I-SID everywhere or using random values increases the risk of conflicts and unintended reachability.

Question 19Fabric design and deployment

Which statement about Fabric Attach is accurate?

  1. It can auto-provision fabric services for attached devices that are not themselves running SPB Correct answer.
  2. It replaces IS-IS as the backbone control protocol
  3. It is used only for wireless controller integration
  4. It requires every endpoint to run an SPB stack

Explanation

Fabric Attach lets non-SPB devices and access switches be auto-provisioned into fabric services, extending fabric benefits to the edge. It does not replace IS-IS or require endpoints to run SPB.

Question 20Fabric design and deployment

What is the effect of configuring multiple equal-cost paths between BCBs in an SPB fabric?

  1. The fabric reverts to spanning-tree behavior
  2. Only one path can ever be used, and the rest are blocked
  3. Traffic can be load-shared across the paths while remaining loop-free Correct answer.
  4. IS-IS is disabled on the redundant links

Explanation

SPB computes shortest-path trees and supports equal-cost multipath, so multiple equal-cost links carry traffic while the topology remains loop-free. It does not fall back to spanning tree or disable IS-IS.

Question 21Fabric design and deployment

An engineer needs to confirm that a BEB is correctly participating in the SPB backbone before attaching services. Which evidence is most relevant?

  1. The BEB shows a full LACP bundle on access ports
  2. The BEB has an active DHCP lease
  3. The BEB has established IS-IS adjacencies with its backbone neighbors Correct answer.
  4. The BEB has a configured management default gateway

Explanation

IS-IS adjacency status confirms the BEB is exchanging topology information with backbone neighbors and is part of the SPB fabric. DHCP, LACP, and management gateway settings do not demonstrate backbone participation.

Question 22Fabric design and deployment

Which scenario best justifies choosing Fabric Connect over a traditional layer-two aggregation design?

  1. The organization requires every switch to run a different control protocol
  2. The organization needs active use of all redundant links and rapid convergence across a large campus Correct answer.
  3. The organization wants to avoid any service segmentation
  4. The organization wants to eliminate all routing from the network

Explanation

Fabric Connect provides loop-free multipath forwarding and fast reconvergence, which suits large environments needing full use of redundant links. It does not remove routing, require per-switch protocol differences, or prevent segmentation.

Question 23Fabric design and deployment

Which element identifies the backbone network instance that a BEB joins when it is provisioned into an Extreme Fabric Connect fabric?

  1. The backbone VSN or fabric identifier configured on the node Correct answer.
  2. The access port duplex setting
  3. The NTP server address
  4. The endpoint MAC address

Explanation

Joining the correct backbone instance requires the node to be configured with the matching backbone VSN or fabric identifier. Port duplex, endpoint MAC, and NTP settings do not determine fabric membership.

Question 24Fabric design and deployment

A designer is mapping an access VLAN to an I-SID on a BEB. What happens to the original VLAN tag as traffic crosses the SPB backbone?

  1. The VLAN tag is preserved bit-for-bit on every BCB
  2. The VLAN tag is rewritten to the BCB's loopback address
  3. The traffic is encapsulated in the backbone service, so the local VLAN tag is not carried unchanged across the core Correct answer.
  4. The VLAN tag is converted to an IS-IS metric

Explanation

The BEB maps the access VLAN to an I-SID and encapsulates the traffic for transport across the SPB backbone, so the local VLAN tag is not carried unchanged over the core. IS-IS metrics and loopback addresses are unrelated to tag handling.

Question 25Fabric design and deployment

Which practice most improves operational visibility when troubleshooting service reachability in a Fabric Connect deployment?

  1. Disabling logging on core nodes to reduce noise
  2. Changing I-SID values repeatedly until traffic flows
  3. Correlating I-SID status and IS-IS adjacency data from the affected BEBs and BCBs Correct answer.
  4. Relying solely on endpoint ping results

Explanation

Effective troubleshooting correlates service state (I-SID status) with control-plane state (IS-IS adjacencies) across the relevant nodes. Ping alone, reduced logging, or random I-SID changes obscure the root cause.

Question 26Fabric design and deployment

Which statement best describes the role of the Backbone Core Bridge (BCB) in an Extreme Fabric Connect deployment?

  1. It provides the backbone transport and forwards SPB frames based on backbone MAC and I-SID, without hosting fabric services. Correct answer.
  2. It maps local VLANs to I-SIDs and provides the anycast gateway for tenant subnets.
  3. It acts as the Fabric Attach server for access switches and assigns I-SIDs to them.
  4. It terminates all I-SIDs and performs inter-VLAN routing for attached access devices.

Explanation

A BCB is an SPB backbone node that switches based on the backbone MAC header and I-SID; it does not terminate service I-SIDs or run anycast gateways. BCBs provide the core transport between BEBs, while BEBs host service endpoints and perform VLAN-to-I-SID mapping. This separation is fundamental to the two-tier Fabric Connect design.

Question 27Fabric design and deployment

An engineer must verify that a new I-SID is operational on a BEB before connecting a customer VLAN. Which command output most directly confirms that the I-SID is active and associated with the correct VSN?

  1. show ip route
  2. show i-sid <id> Correct answer.
  3. show vlan basic
  4. show isis spb adjacencies

Explanation

The 'show i-sid <id>' command displays the I-SID configuration and its operational state, including the associated VSN and whether the I-SID is active. This directly confirms that the service identifier is correctly provisioned on the BEB. The other commands show adjacency, VLAN, or routing information but not the I-SID-to-VSN binding state.

Question 28Fabric design and deployment

Which design choice most directly limits the impact of an incorrectly configured I-SID in a large Fabric Connect fabric?

  1. Enabling IP Shortcut Routing on every BEB to reduce I-SID scope
  2. Applying a structured I-SID allocation plan with per-tenant or per-service ranges Correct answer.
  3. Configuring all BEBs in the same VSN to ensure consistent I-SID visibility
  4. Using a single shared I-SID for all tenant services to simplify operations

Explanation

A structured I-SID allocation plan assigns unique ranges to tenants or service types, so a misconfigured I-SID is confined to its intended range and does not collide with unrelated services. This limits the blast radius by preventing accidental overlap. Sharing a single I-SID or placing everything in one VSN increases the scope of any error.

Question 29Fabric design and deployment

A designer is planning a Fabric Connect deployment that must support tenant separation with overlapping IP subnets. Which fabric construct provides each tenant with an independent routing table?

  1. A unique I-SID per tenant mapped to a dedicated VRF on the BEBs Correct answer.
  2. A unique backbone VLAN (B-VLAN) per tenant to separate traffic
  3. A dedicated BCB pair per tenant to provide routing isolation
  4. A separate SPB area for each tenant to isolate topology information

Explanation

VRF instances on BEBs provide independent routing tables, and each tenant's I-SID is mapped to the appropriate VRF so overlapping IP subnets remain isolated. The fabric transports I-SIDs transparently, so tenant separation is achieved through VRF and I-SID mapping rather than separate topologies. SPB areas, B-VLANs, and dedicated BCBs do not provide per-tenant routing tables.

Question 30Fabric design and deployment

Which statement accurately describes how Fabric Attach elements obtain service I-SID assignments from the fabric?

  1. Fabric Attach clients send requests to a Fabric Attach server, which assigns I-SIDs and provisions the corresponding BEB service. Correct answer.
  2. Fabric Attach clients derive I-SIDs automatically from their management IP address.
  3. Fabric Attach clients statically configure I-SIDs and advertise them to the fabric via IS-IS.
  4. Fabric Attach clients use DHCP options to discover I-SID assignments from a central server.

Explanation

Fabric Attach uses a client-server model in which access elements request service assignment from a Fabric Attach server, typically integrated with a BEB. The server assigns the I-SID and provisions the fabric service so the access port is mapped without manual configuration. This automation reduces provisioning errors and speeds service activation.

Question 31Fabric design and deployment

An engineer notices that traffic between two BEBs takes a longer path than the shortest available path in the SPB fabric. Which factor best explains this behavior?

  1. The I-SID is mapped to the wrong VSN on one BEB
  2. The B-VLAN is not configured on the intermediate BCBs
  3. IP Shortcut Routing is disabled, so traffic follows the SPB tree rather than the shortest path Correct answer.
  4. SPB always uses a single designated path and ignores equal-cost links

Explanation

SPB normally forwards unicast traffic along the shortest path tree, but if IP Shortcut Routing is disabled, traffic may follow the topology tree rather than the optimal path. Enabling IP Shortcut Routing allows BEBs to use direct shortest paths for IP traffic. The other options describe misconfigurations that would cause different symptoms.

Question 32Fabric design and deployment

A network designer is comparing Fabric Connect with a traditional spanning-tree aggregation design. Which characteristic most strongly justifies Fabric Connect for a large campus with many access switches?

  1. Fabric Connect replaces all access switches with BCBs
  2. Fabric Connect eliminates the need for any layer-3 routing in the campus
  3. Fabric Connect uses SPB to provide multipath forwarding and fast convergence without spanning-tree blocking Correct answer.
  4. Fabric Connect requires fewer physical links because it uses a single active path

Explanation

Fabric Connect uses SPB to enable multipath forwarding and rapid convergence, avoiding the blocked links and slow convergence typical of spanning-tree designs. This makes it well suited to large campuses where resiliency and efficient use of links are important. Fabric Connect does not eliminate layer-3 routing or require replacing access switches.

Question 33Fabric design and deployment

When a BEB maps an access VLAN to an I-SID, what happens to the original VLAN tag as the frame traverses the SPB backbone?

  1. The original VLAN tag is replaced by the I-SID in the SPB header, and the original tag is restored at the egress BEB Correct answer.
  2. The original VLAN tag is removed and never restored, relying on I-SID for final delivery
  3. The original VLAN tag is translated to the B-VLAN tag and remains unchanged at egress
  4. The original VLAN tag is preserved end-to-end across the backbone

Explanation

At the ingress BEB, the access VLAN tag is mapped to an I-SID carried in the SPB header, and the original VLAN tag is not used for forwarding in the backbone. At the egress BEB, the I-SID is mapped back to the appropriate local VLAN, restoring a VLAN tag for delivery. This allows each site to use local VLANs independently of the fabric service.

Question 34Fabric design and deployment

Which protocol does the SPB control plane in Extreme Fabric Connect use to exchange topology information between backbone bridges?

  1. EIGRP
  2. BGP
  3. OSPF
  4. IS-IS Correct answer.

Explanation

SPB uses IS-IS as its link-state control plane to exchange topology information and compute shortest paths between backbone bridges. IS-IS extensions carry the SPB-specific attributes needed for the fabric. OSPF, BGP, and EIGRP are not used for SPB topology exchange.

Question 35Fabric design and deployment

A network engineer is deploying a two-tier Fabric Connect design and wants redundant BCBs so that loss of one core node does not disrupt services. Which design approach best achieves this?

  1. Deploy a single BCB with redundant power supplies and supervisor modules
  2. Deploy two BCBs in separate IS-IS areas to isolate failures
  3. Deploy at least two BCBs and ensure they are interconnected with redundant links and participate in the same IS-IS area Correct answer.
  4. Rely on Fabric Attach to provide redundancy for the BCB layer

Explanation

Redundant BCBs in the same IS-IS area with redundant interconnections allow the SPB fabric to reconverge and maintain service if one BCB fails. Multiple BCBs provide path diversity and node redundancy. Separate IS-IS areas would isolate the BCBs and prevent them from providing a single resilient backbone.

Question 36Fabric design and deployment

An engineer needs to confirm that a BEB is correctly participating in the SPB backbone before attaching services. Which verification step is most appropriate?

  1. Check that the BEB has Fabric Attach client enabled
  2. Check the IS-IS adjacency status and SPB-enabled interfaces Correct answer.
  3. Verify that the BEB has an IP address in the management VLAN
  4. Confirm that the BEB has a default route to the core

Explanation

Checking IS-IS adjacency status and SPB-enabled interfaces confirms that the BEB has formed backbone adjacencies and is participating in SPB. This is a prerequisite for service attachment. Management IP reachability, default routes, and Fabric Attach client status do not directly verify SPB participation.

Question 37Fabric design and deployment

A designer wants to isolate tenant traffic so that each tenant has its own routing table while sharing the same physical fabric. Which combination is required on the BEBs?

  1. A unique VSN per tenant and a shared I-SID
  2. A unique nickname per tenant and a shared I-SID
  3. A unique IS-IS area per tenant and a shared VRF
  4. A unique VRF per tenant and I-SIDs mapped to the appropriate VRF Correct answer.

Explanation

VRFs provide independent routing tables on BEBs, and I-SIDs are mapped to the appropriate VRF so each tenant's traffic is isolated while sharing the physical fabric. This allows overlapping IP subnets between tenants. Unique VSNs, IS-IS areas, or nicknames do not by themselves provide per-tenant routing tables.

Question 38Fabric design and deployment

Which outcome is a direct result of enabling IP Shortcut Routing on a BEB in a Fabric Connect fabric?

  1. IP traffic between BEBs can use the shortest path rather than following the SPB topology tree Correct answer.
  2. I-SIDs are automatically assigned to access VLANs without Fabric Attach
  3. The BEB stops participating in IS-IS and relies on static routes
  4. All traffic between BEBs is forced through the nearest BCB

Explanation

IP Shortcut Routing allows BEBs to forward IP traffic along the shortest path across the SPB fabric instead of following the topology tree, improving efficiency. It does not assign I-SIDs or stop IS-IS participation. This feature is particularly useful for optimizing traffic between BEBs.

Question 39Fabric design and deployment

In an Extreme Fabric Connect deployment, which identifier is used to map a customer service instance to a backbone VSN so that the service can be carried across the SPB core?

  1. The I-SID assigned to the service Correct answer.
  2. The Nickname of the ingress BEB
  3. The IS-IS system ID of the BCB
  4. The B-VLAN used by the backbone core

Explanation

Fabric Connect services are identified end-to-end by the I-SID, which is carried in the SPB data plane and binds an access service instance to a backbone VSN. The B-VLAN, Nickname, and IS-IS system ID are infrastructure identifiers, not service-mapping identifiers.

Question 40Fabric design and deployment

A designer is planning a Fabric Connect fabric where access switches are not SPB-capable and must be onboarded with minimal manual configuration. Which approach best meets this requirement?

  1. Connect access switches as BEBs and let them originate their own I-SIDs
  2. Statically map every access VLAN to a unique I-SID on each access switch
  3. Configure each access switch as a full BCB with IS-IS adjacencies
  4. Enable Fabric Attach on the access switches and on the BEB-facing ports Correct answer.

Explanation

Fabric Attach lets non-SPB access devices signal their service requirements to the fabric, and the BEB can then assign I-SIDs automatically, which minimizes manual provisioning. Making access switches BCBs or BEBs raises complexity and requires SPB support they lack, while static per-switch mapping defeats the goal of minimal configuration.

Question 41Fabric implementation and configuration

In Extreme Fabric Connect, what is the primary role of the Backbone Edge Bridge (BEB) node?

  1. It provides the out-of-band console server used to configure the fabric
  2. It acts as the DHCP relay and default gateway for the management VLAN only
  3. It forwards frames between backbone core nodes using only the backbone MAC table
  4. It attaches access-side devices to the fabric and performs I-SID mapping at the fabric edge Correct answer.

Explanation

A BEB sits at the boundary of the SPBM backbone and provides customer or access-side attachment, mapping VLANs and services into I-SIDs. Core transport between BEBs is handled by Backbone Core Bridges, not by the BEB's own edge function.

Question 42Fabric implementation and configuration

Which statement describes how a Backbone Core Bridge (BCB) handles traffic in an Extreme Fabric Connect network?

  1. It performs NAT between fabric I-SIDs and the management address space
  2. It terminates I-SIDs and rewrites customer VLAN tags at each hop
  3. It forwards based on backbone MAC and I-SID without learning customer MAC addresses Correct answer.
  4. It runs OSPF to exchange customer routes with the access layer

Explanation

BCBs are transit nodes that forward SPBM-encapsulated frames using the backbone MAC and I-SID information in the header. They do not need to learn customer MAC addresses, which keeps core tables small and stable.

Question 43Fabric implementation and configuration

Which protocol does Extreme Fabric Connect use to build and maintain backbone topology and to distribute backbone MAC reachability?

  1. IS-IS with SPBM extensions Correct answer.
  2. BGP with route reflectors
  3. RIPng with split horizon
  4. OSPFv3 with graceful restart enabled

Explanation

Fabric Connect is built on Shortest Path Bridging MAC mode, which uses IS-IS as the link-state routing protocol carrying SPBM TLVs. IS-IS distributes backbone MAC and I-SID reachability so nodes can build shortest-path forwarding trees.

Question 44Fabric implementation and configuration

What does an I-SID identify in an Extreme Fabric Connect deployment?

  1. A service instance that isolates a set of endpoints across the fabric Correct answer.
  2. A physical backbone port index on each BCB
  3. An authentication realm for fabric attach clients
  4. A routing area number within the IS-IS domain

Explanation

The I-SID is a 24-bit service identifier that scopes a service instance across the SPBM domain, keeping traffic for different services isolated even when they share the backbone. Endpoints are mapped into I-SIDs at the BEB edge.

Question 45Fabric implementation and configuration

A design requires that two separate customer VLANs on the same BEB be kept in completely separate Layer 2 service instances across the fabric. What should you configure?

  1. Map both VLANs to the fabric attach port and disable I-SID mapping
  2. Map both VLANs to one I-SID and rely on VLAN tags for separation
  3. Map each VLAN to a distinct I-SID so their broadcast domains stay isolated Correct answer.
  4. Map both VLANs to the same I-SID and enable split-horizon on the uplink

Explanation

Each I-SID defines an independent service instance, so assigning different I-SIDs to the two VLANs preserves Layer 2 isolation across the backbone. Sharing an I-SID would merge the broadcast domains into one service.

Question 46Fabric implementation and configuration

Which statement best describes Fabric Connect's behavior for unicast traffic compared with traditional spanning-tree Ethernet?

  1. It requires static MAC entries on every BCB along the path
  2. It uses shortest-path trees per source with all backbone links active Correct answer.
  3. It floods all unicast frames to every BEB and filters at the edge
  4. It blocks redundant links and forwards over a single spanning-tree topology

Explanation

SPBM computes shortest-path trees rooted at each source BEB, so redundant backbone links can all carry traffic instead of being blocked. This provides multipathing and avoids the idle-link penalty of spanning tree.

Question 47Fabric implementation and configuration

What is the purpose of the Nickname assigned to a Fabric Connect node?

  1. It is a short identifier used to derive the node's SPBM system ID for forwarding Correct answer.
  2. It is the password used when a node joins the IS-IS area
  3. It is the DNS hostname published for the switch's management address
  4. It is the SNMP community string used by the fabric manager

Explanation

Each SPBM node has a nickname that, combined with the system ID, forms a unique identifier used to build the multicast and unicast forwarding entries in the backbone. Nicknames must be unique within the SPBM domain.

Question 48Fabric implementation and configuration

You are enabling a Layer 2 VSN on a BEB for a customer VLAN. Which configuration element must be consistent on every BEB that participates in that service?

  1. The NTP server address on each node
  2. The SNMP trap destination list
  3. The I-SID value associated with the service Correct answer.
  4. The management IP subnet of each BEB

Explanation

All BEBs providing the same service must use the same I-SID so their endpoints land in the same service instance. The I-SID is the fabric-wide identifier that ties the edge attachments together.

Question 49Fabric implementation and configuration

Which Fabric Connect feature lets an access switch that is not running SPBM join the fabric and receive its VLAN-to-I-SID mapping automatically from the edge?

  1. OSPF passive interface
  2. Fabric Attach Correct answer.
  3. Link aggregation control protocol
  4. VRF Lite

Explanation

Fabric Attach allows non-SPBM access devices to connect to a BEB and have their service mappings provisioned automatically through an attach control protocol. This extends fabric services to conventional switches without running IS-IS on them.

Question 50Fabric implementation and configuration

Which statement about a Layer 3 VSN in Fabric Connect is accurate?

  1. It provides an isolated IP routing domain mapped to a VRF with its own I-SID Correct answer.
  2. It can only carry traffic within a single IS-IS area
  3. It disables IS-IS on the participating BEBs
  4. It requires a dedicated physical link between every pair of BEBs

Explanation

A Layer 3 VSN creates an isolated routing instance, or VRF, whose IP interfaces are mapped into an I-SID so the routing domain spans the fabric. Each VSN keeps its routes separate from other virtual routing instances.