Networking

An ISP is designing an MPLS core network and needs to choose an IGP that supports fast convergence. Which IGP meets this requirement and is most commonly used in MPLS core networks?

Which TWO of the following are characteristics of MPLS-TE (Traffic Engineering)?

Based on the exhibit, what is the purpose of the 'mpls ldp neighbor ... password cisco' commands?

A service provider is designing a Layer 2 MPLS VPN to connect multiple customer sites. Which technology should be used to provide end-to-end Ethernet service with MAC address transparency and support for multiple customer VLANs?

A service provider is deploying L3VPN with inter-AS option B (ASBR-to-ASBR). Which TWO statements are true about this design?

Which TWO statements correctly describe the use of OSPF in a service provider network?

A service provider is deploying a new MPLS core network. The network has four routers: P1, P2, PE1, and PE2. OSPF is used as the IGP. The engineer configures MPLS LDP on all interfaces. After enabling LDP, the engineer notices that the LDP session between P1 and P2 is established, but no labels are exchanged for the loopback0 interfaces of PE1 and PE2. The loopback0 addresses are advertised in OSPF. The engineer verifies that the OSPF routes are present in the routing table of all routers. What is the most likely reason for the missing labels?

You are a network engineer at a service provider. Your network uses MPLS L3VPN with OSPF as the IGP and LDP for label distribution. A customer has two sites connected to different PEs (PE1 and PE2) in the same VPN. The customer's CE routers are running eBGP with the PEs. Recently, the customer reports that traffic between the two sites is intermittently dropping. Upon investigation, you find that the BGP session between PE1 and the CE at site A goes down briefly every few minutes. The logs on PE1 show BGP notifications with error code 'Hold Timer Expired'. The CE router at site A is a low-end device with limited CPU. What is the most likely cause and the best course of action?

Drag and drop the steps to configure a VLAN on a Cisco switch into the correct order.

Drag and drop the steps to configure a Layer 3 interface on a Cisco switch (SVI) into the correct order.

During a network migration from EIGRP to OSPF, you notice that some routes are being redistributed incorrectly, causing routing loops. The OSPF domain uses area 0 and area 1. The EIGRP domain uses AS 100. Which configuration change would best prevent loops during the migration?

A network engineer is troubleshooting an OSPF adjacency issue between two routers connected via a serial link. The routers are configured with point-to-point network type. The adjacency stays in EXSTART state. What is the most likely cause?

A service provider router receives a route with a higher specific prefix length than the same prefix in the routing table. Which route will be preferred?

In an MPLS network, a PE router receives a VPNv4 route from a route reflector. The route is not being installed in the VRF table. Which condition could cause this?

Refer to the exhibit. What is the role of this router for prefix 10.0.1.0/24?

Which technology should be used to provide per-flow load balancing across multiple equal-cost paths in an MPLS network while preserving packet order?

A service provider is running OSPF in their core network. After a link failure, routing convergence is taking longer than expected. The engineer suspects the issue is related to the SPF calculation. Which OSPF feature can reduce the SPF calculation time?

An engineer is troubleshooting a BGP route reflector setup. Clients are not receiving all routes. The 'show bgp neighbors' output shows a state of 'Active'. What is the most likely cause?

A network engineer needs to ensure that a specific customer's traffic is not adversely affected by other customers' traffic in a shared MPLS core. Which technology should be used?

Which statement about the use of MTU in an MPLS network is correct?

An ISP is designing a new core network using MPLS-TE. They require very fast failure detection for link and node failures to minimize traffic loss. Which two technologies should they combine? (Choose two.)

Which LISP feature allows a device to register its location to a mapping system so that another device can find it?

A service provider is troubleshooting BGP route selection between two eBGP peers. The router receives a prefix from Peer A with local preference 150 and AS path length 3. From Peer B, the same prefix has local preference 100 and AS path length 2. Which route will be preferred?

Which OSPF neighbor state indicates that a router has received a hello packet from a neighbor but the neighbor's Router ID is not yet seen in its own hello packet?

Which QoS mechanism marks packets at the edge of the network to classify traffic into different service classes?

Segment Routing with TI-LFA (Topology Independent Loop-Free Alternate) provides fast convergence. Which statement accurately describes TI-LFA?

Which TWO statements correctly describe differences between PIM dense mode and PIM sparse mode? (Choose two.)

An engineer is deploying Segment Routing in an MPLS network. To ensure that routers can forward packets based on SR-MPLS labels without requiring LDP, which requirement must be met?

In a Layer 3 MPLS VPN, a customer site that is part of VRF RED is unable to communicate with another site that is also in VRF RED. The 'show ip bgp vpnv4 vrf RED' command shows the routes, but the router does not install them in the routing table. Which configuration element is most likely missing?

An engineer configures the 'set-overload-bit' command on an IS-IS router. What is the immediate effect on the network?

An engineer configures MPLS TE tunnels. After configuration, the tunnel remains down. The 'show mpls traffic-eng tunnels' output shows 'Tunnel is down - path computation failed'. What is the most likely cause?

An OSPF network uses point-to-point links. The engineer notices that LSAs are being flooded every 30 minutes even when no topology changes occur. What is the most likely reason?

An engineer is troubleshooting BGP convergence. The router has multiple paths for a prefix, but it selects a path with a lower local preference over a path with a higher local preference. The higher local preference path is from an EBGP peer. What could cause this?

Which THREE of the following are characteristics of Segment Routing (SR-MPLS) compared to traditional MPLS with LDP?

Refer to the exhibit. Which statement is correct about the LDP bindings for prefix 10.0.0.0/24?

When implementing MPLS TE tunnels in a service provider core, what is the purpose of the 'affinity' attribute?

Which TWO BGP path attributes are considered before AS-path length in the default best-path selection process?

A service provider's network uses MPLS TE with Fast Reroute (FRR) for link protection. After a fiber cut on a core link, the traffic is rerouted via a backup tunnel, but the backup tunnel's path suffers from high latency. The customer complains about poor voice quality. What can be done to avoid this scenario in future deployments?

A service provider is deploying multicast service for IPTV using PIM-SM with a single RP. During high traffic periods, the RP becomes overloaded. What is the most scalable solution to distribute the load across multiple RPs?

Which TWO tasks are required when implementing segment routing in an MPLS network?

An SP engineer is configuring IS-IS on a router and specifies a NET address of 49.0001.1921.6800.1001.00. What does the '00' at the end represent?

An SP network uses MPLS to provide IPv6 connectivity over an IPv4 backbone using 6PE. Which BGP extension is required on the provider edge routers to exchange IPv6 prefixes with an IPv4 next-hop?

An OSPF network is configured with RSVP-TE. Which OSPF extension is used to advertise TE link attributes such as bandwidth and administrative group?

In BGP route reflection, what is the purpose of the ORIGINATOR_ID attribute?

An SP is implementing IPv6 transition using MAP-T. Which encapsulation method does MAP-T use?

In IS-IS, which metric type supports traffic engineering (TE) and is required for segment routing?

In a BGP confederation, which AS number is used in the AS_PATH to prevent loops within the confederation?

An SP is deploying IPv6 using 6VPE. Which THREE components are required? (Choose three.)

An engineer is configuring IS-IS in a service provider network. The network uses wide metrics for traffic engineering. Which TLV is mandatory for IS-IS to carry traffic engineering (TE) information in accordance with RFC 5305?

In an IS-IS network, a router has a NET of 49.0001.1921.6800.1001.00. What does the '00' at the end represent?

A service provider is deploying OSPFv3 for IPv6 in its core. The network uses multiple areas. Which LSA type is used by OSPFv3 to advertise prefix information for inter-area routes?

Which BGP attribute is used to prefer a specific entry point into an AS when multiple ASBRs are advertising the same prefix to a neighboring AS?

Which OSPF network type elects a Designated Router (DR) and Backup Designated Router (BDR) to reduce the number of adjacencies on a multi-access segment?

An SP is designing an OSPF network with a totally stubby area to reduce the LSA database. Which LSA types are blocked by default in a totally stubby area?

In IS-IS, what is the result of configuring wide metrics on all interfaces?

A service provider is implementing 6VPE to provide IPv6 L3VPN services over an MPLS core. Which BGP address family must be configured on the PE routers to exchange IPv6 VPN routes?

An SP is deploying IS-IS fast convergence using Partial Route Computation (PRC). Under which condition does PRC occur?

Which three BGP attributes are considered in the route selection process before comparing MED? (Choose three.)

In IS-IS, which type of router is responsible for routing between different areas and also maintains a Level 1 Link State Database?

An SP network engineer configures IS-IS with wide metrics. Which statement is true about IS-IS wide metrics compared to narrow metrics?

A service provider uses OSPFv3 for IPv6 routing in the core. Which statement correctly describes OSPFv3 adjacency formation on a broadcast multiaccess network?

In IS-IS, what is the purpose of the Partial Route Computation (PRC)?

Which IS-IS TLV is used to carry IPv6 reachability information?

In OSPF Traffic Engineering (TE) extensions for RSVP-TE, which LSA type is used to carry TE information?

A service provider is designing an OSPF network with multiple areas. Which three area types prevent Type 5 LSAs from entering the area (choose three)?

An SP engineer configures IS-IS fast convergence mechanisms. Which three techniques help achieve sub-second convergence in IS-IS?

Which IS-IS level is used for routing within an area?

In BGP route selection, which attribute is considered before LOCAL_PREF?

In IS-IS, which TLV is used to carry traffic engineering information for MPLS-TE?

Which OSPF adjacency type requires DR/BDR election on a multi-access network?

A service provider wants to provide IPv6 connectivity over an existing MPLS IPv4 core using BGP extensions. Which technology should be used?

In OSPFv3, which of the following is true about the protocol's operation?

A service provider is implementing Segment Routing in an IS-IS network. Which TLV is used to advertise the Segment Routing Global Block (SRGB)?

Which OSPF area type can import external routes as Type 7 LSAs?

An SP network is migrating from IS-IS narrow metrics to wide metrics. What is a key advantage of using wide metrics?

In OSPFv3 (for IPv6), which of the following statements is true regarding OSPFv3 packet format and authentication?

A service provider is implementing BGP PIC (Prefix Independent Convergence) for its core network. Which mechanism does BGP PIC primarily rely on to achieve fast convergence?

Which OSPF area type is most suitable for a service provider's customer-facing network where external routes are blocked, but internal routes (including inter-area) are allowed, and the area should not accept Type 5 LSAs?

In BGP, what is the purpose of the ORIGINATOR_ID attribute in a route reflector environment?

Which technology allows an IPv6-only customer edge router to connect to an MPLS provider edge router using IPv4 transport, encapsulating IPv6 packets in MPLS with a labeled IPv4 next-hop?

An engineer is configuring IS-IS fast convergence. Which mechanism provides sub-second failure detection independently of the routing protocol?

In OSPF TE extensions for RSVP-TE, which LSA type is used to carry TE information (such as link attributes) in OSPF?

Which BGP attribute is used to influence inbound traffic to a multi-homed AS by indicating the preferred entry point?

A service provider is designing an OSPF network with multiple areas. Which TWO area types allow external routes (Type 5 LSAs) to be injected into the area? (Choose two.)

An engineer is configuring BGP route reflectors to scale iBGP. Which TWO attributes are used to prevent routing loops in a route reflector cluster? (Choose two.)

Which IS-IS router type maintains a full Layer 2 routing table of all areas and can act as a gateway between areas?

In BGP, an SP router receives multiple routes to the same prefix. The first route has a weight of 100, LOCAL_PREF of 200, AS_PATH length 3, and is learned via eBGP. The second route has weight 50, LOCAL_PREF 150, AS_PATH length 2, and is learned via iBGP. According to BGP route selection, which route will be preferred?

Which IS-IS TLV is used to carry Traffic Engineering (TE) information such as link bandwidth and TE metric in modern SP networks?

A service provider is implementing 6PE to carry IPv6 traffic over an existing MPLS IPv4 core. Which BGP extension is required on the provider edge (PE) routers to exchange IPv6 prefixes with an IPv4 next-hop?

An SP network uses OSPF with RSVP-TE for traffic engineering. Which OSPF extension is required to advertise TE link parameters such as maximum reservable bandwidth?

In an IS-IS network, a service provider wants to achieve fast convergence using Partial Route Computation (PRC). Which of the following events triggers a PRC instead of a full SPF?

An SP network is implementing BGP PIC (Prefix Independent Convergence) for fast failover. What is the primary mechanism used by BGP PIC to achieve sub-second convergence?

In IS-IS, which type of metric uses 24 bits (wide) to allow higher link bandwidth values and is required for TE support?

A service provider is configuring BGP route reflectors to scale iBGP. Which two mechanisms are used to prevent routing loops in a route reflector environment? (Choose two.)

An SP network uses OSPFv3 for IPv6 routing. Which three statements about OSPFv3 are true? (Choose three.)

A service provider is implementing MAP-T (Mapping of Address and Port using Translation) to transition customers from IPv4 to IPv6. Which two characteristics of MAP-T are true? (Choose two.)

In an OSPF network, an engineer wants to reduce the size of the routing table and prevent external routes from being advertised into an area. Which area type should be configured?

A service provider uses BGP route reflectors to scale iBGP. A route reflected from a route reflector arrives at a client with the originator-id set. What is the purpose of the originator-id attribute?

An ISP is implementing 6PE to provide IPv6 connectivity over an MPLS network that only supports IPv4 in the core. In 6PE, how are IPv6 prefixes carried across the MPLS backbone?

In IS-IS, what is the purpose of the System ID portion of the NET address?

A service provider is deploying BGP PIC (Prefix Independent Convergence) for edge routers. What is the primary benefit of BGP PIC?

In OSPFv3, what change was introduced compared to OSPFv2 for supporting IPv6?

Which IS-IS metric type is required for traffic engineering and segment routing?

A service provider wants to enable fast convergence for OSPF networks. Which feature should be enabled to detect link failures in sub-second time?

An ISP is implementing MAP-T to transition to IPv6. Which of the following best describes MAP-T?

In an OSPF network, an area is configured as a Not-So-Stubby Area (NSSA). Which statement about LSA types in this area is correct?

An SP uses OSPF with Traffic Engineering extensions to support RSVP-TE. Which LSA type is used to carry TE information in OSPF?

In IS-IS, a router is configured as L1 only. Which statement is true regarding its routing table?

Which BGP attribute is used to influence inbound traffic to an AS by indicating the preferred path into the AS?

A service provider is deploying BGP PIC (Prefix Independent Convergence) to improve convergence after a link failure. Which mechanism does BGP PIC leverage to achieve fast failover?

Which TWO of the following are characteristics of IS-IS Partial Route Computation (PRC)? (Choose two.)

Which TWO of the following are types of OSPF stub areas? (Choose two.)

An SP network is running OSPFv3 for IPv6 and needs to support traffic engineering extensions for RSVP-TE. Which three statements about OSPFv3 TE extensions are true?

An engineer is designing an iBGP route reflector topology to improve scalability. Which two statements about BGP route reflectors are correct?

An SP network is using IS-IS and wants to achieve fast convergence using BFD. Which two statements about BFD in IS-IS are correct?

A service provider is deploying MPLS L3VPN services using Cisco IOS XR. The PE routers run MP-BGP and need to forward customer traffic. Which label operation does the ingress PE perform on packets destined for a remote VPN prefix?

A service provider runs BGP on PE routers to exchange IPv4 unicast routes with customers. The network operations team wants to limit the number of IPv4 unicast prefixes that can be received from any single eBGP peer to 5000. If the limit is exceeded, the session should be torn down and a log message generated. Which BGP configuration accomplishes this?

A service provider runs RSVP-TE in its MPLS core. An engineer must ensure that when a primary TE tunnel to a PE router fails, a backup tunnel carries traffic within 50 ms while the headend recalculates a new path. Which RSVP-TE mechanism should be configured on the headend to meet this requirement?

An engineer configures an MPLS L3VPN on a Cisco IOS XR PE router. The customer VRF uses a route distinguisher of 65000:100 and a route target of 65000:100 for both import and export. A second PE router in the same AS advertises the same customer prefix with a different route distinguisher but the same route target. Which statement describes how the receiving PE handles these VPNv4 routes?

A service provider wants to automate configuration of hundreds of Cisco IOS XR core routers using a model-driven approach. The operations team requires YANG-based programmatic access that supports candidate configuration, commit, and rollback over a single session. Which interface should be enabled on the routers?

A service provider is running IS-IS in a large core network. An engineer notices that some routers are not receiving detailed prefix information for certain areas. Which IS-IS LSP type is used to advertise IP prefixes in a multi-area environment?

A service provider is deploying Segment Routing over an MPLS data plane in an IS-IS core. The design must support TI-LFA and SR-MPLS forwarding without RSVP-TE. Which two configuration elements are required on the core routers to enable this design? (Choose two.)

A service provider is deploying Segment Routing over an MPLS core using OSPFv2 as the IGP. The network engineer must configure the routers to support SR-MPLS and ensure that adjacency SIDs are generated for all core links. Which two configuration steps are required on each router? (Choose two.)

An engineer is troubleshooting an MPLS L3VPN where a customer prefix is present in the VRF routing table on the local PE but traffic is dropped when forwarded toward the remote PE. The label stack shows the transport label is imposed but the VPN label is missing. Which configuration issue most likely explains this behavior?

A service provider runs OSPF in its core with several ABRs connecting to a non-backbone area. The network architect wants to block specific prefixes from being advertised into the backbone area while still allowing them to be used within the originating area. Where should the engineer apply the OSPF area filter-list command?

An engineer is configuring MPLS LDP in an SP core. The IGP is OSPF, and all interfaces are enabled for MPLS. A new router is added, but LDP sessions fail to establish with its neighbors. The engineer verifies that OSPF adjacencies are up and that the loopback interfaces are reachable. Which step should the engineer take next to troubleshoot the LDP session failure?

A service provider is deploying MPLS L3VPN services using BGP. The PE routers are configured with VRFs and use MP-BGP to exchange VPNv4 routes. A customer reports that routes from one site are not being installed in the VRF routing table on a remote PE, even though the VPNv4 routes are present in the BGP table. What is the most likely cause?

A network engineer is configuring an MPLS L3VPN on a Cisco IOS-XR PE router. The engineer wants to verify that the PE router has established a VPNv4 BGP session with the route reflector. Which command should be used to display the VPNv4 BGP summary?

A service provider runs RSVP-TE in its MPLS core. The headend router must compute a path that satisfies a bandwidth guarantee and a specific administrative group (link color) requirement. The network uses CSPF. Which statement correctly describes how the headend selects the path for the tunnel?

An engineer is configuring a Cisco router for MPLS LDP in a service provider core. The router must establish LDP sessions with directly connected neighbors and advertise labels for all IGP prefixes. Which command is required to enable LDP on an interface?

A network engineer is configuring a Cisco IOS XR router to participate in a BGP-free core for a large service provider. The design requires that the core routers do not run BGP and that MPLS labels are used to forward traffic. Which technology should be implemented on the core routers to achieve this?

A service provider is implementing MPLS Traffic Engineering (TE) with RSVP-TE. An engineer notices that a TE tunnel is not being established, and the path computation fails. The IGP is OSPF, and TE extensions are enabled. Which OSPF LSA type is used to carry TE information for path computation?

A service provider runs MPLS L3VPN over an MPLS core. The PE routers use OSPF as the IGP and iBGP for VPNv4 routes. A new PE router is added, but it cannot establish an LDP session with its directly connected P router. The engineer verifies that OSPF adjacency is up and the loopback interfaces are reachable. Which configuration on the new PE is the most likely cause of the LDP session failure?

A service provider is using MPLS L3VPN with BGP. A PE router receives a VPNv4 route with an extended community of route-target 65000:100. The VRF on the PE is configured with import route-target 65000:100 and export route-target 65000:200. What is the result when the PE processes this route?

A service provider is deploying MPLS Traffic Engineering (TE) with RSVP-TE in its core. The network uses OSPF as the IGP. The engineer notices that TE tunnels are not being established because the headend router does not have the TE database populated with link attributes. Which OSPF LSA type is responsible for carrying TE information in this scenario?

A service provider runs BGP on PE routers with multiple iBGP next hops. The network operator wants to reduce the BGP convergence time after a link failure by precomputing a backup path for the BGP next hop. Which BGP feature should be enabled on the PE routers?

A service provider is deploying a BGP-based MPLS L3VPN. The PE routers are configured with VRFs and MP-BGP for VPNv4. A customer reports that routes from one site are not being installed in the VRF of another site, even though the VPNv4 routes are present on the remote PE. Which BGP feature must be configured to allow the PE to import the VPNv4 routes into the correct VRF?

A service provider is deploying BGP in its core network. The design requires fast convergence and high availability. Which two BGP features should be implemented to achieve sub-second failure detection and to minimize traffic loss? (Choose two.)

An engineer is configuring MPLS LDP on a Cisco router. The router must only advertise label bindings for prefixes that are in the global routing table and must not allocate labels for prefixes learned from a specific customer VRF. Which LDP feature should be configured?

A service provider is using Segment Routing with MPLS data plane. The IGP is OSPFv2. An engineer needs to configure a router to advertise its Segment Routing Global Block (SRGB) and prefix-SIDs. Which OSPF configuration is required?

A network engineer is configuring a Cisco router to participate in an MPLS L3VPN. The router is a PE that must exchange VPNv4 routes with other PE routers. Which address family must be activated in BGP to support this?

A service provider is implementing MPLS Traffic Engineering (TE) with RSVP-TE in its core network. The network uses OSPF as the IGP. The provider wants to ensure that TE tunnels are established over paths that meet specific bandwidth constraints. Which OSPF LSA type carries the TE information required for path computation?

Which protocol is used by Cisco IOS XR routers to distribute MPLS labels for IPv4 prefixes in a service provider core network?

A service provider is using BGP for its MPLS L3VPN service. The network engineer wants to ensure that the PE routers can forward traffic using the correct label stack. Which BGP attribute is used to carry the MPLS label in VPNv4 route advertisements?

Which protocol is used by MPLS LDP to distribute label bindings between routers?

An engineer is troubleshooting an MPLS L3VPN where a PE router is not importing routes into the correct VRF. The PE receives VPNv4 routes with route target 65000:100, but the VRF 'CUSTOMER_A' is configured with route target 65000:200. What is the most likely result?

An engineer is troubleshooting an MPLS L3VPN where customer routes are not being installed in the VRF on the remote PE. The PE routers exchange VPNv4 routes via iBGP. Which configuration error is most likely causing the issue?

A service provider is deploying Segment Routing with TI-LFA (Topology Independent Loop-Free Alternate) for fast convergence in its core network. The network uses IS-IS as the IGP. An engineer must ensure that TI-LFA is operational. Which statement accurately describes a requirement for TI-LFA?

A service provider network uses OSPF as the IGP. An engineer is troubleshooting a routing issue and notices that a router is not installing a route to a specific network in its routing table, even though the network is advertised by a neighbor. The engineer suspects a filter is applied. Which OSPF feature can be used to filter routes from being installed in the routing table without affecting the link-state database?

A service provider is deploying RSVP-TE in its MPLS core. An engineer is configuring a TE tunnel from R1 to R4 with a specific bandwidth requirement. The path computation must avoid a specific link due to maintenance. Which RSVP-TE object is used in the Path message to specify the explicit route?

A service provider is deploying a BGP-based MPLS L3VPN. The PE routers are running eBGP with the CE routers and iBGP with each other for VPNv4 routes. An engineer notices that the PE routers are not exchanging VPNv4 routes. Which configuration is required on the PE routers to enable the exchange of VPNv4 routes over the iBGP session?

A service provider is deploying MPLS L3VPN with BGP route reflectors. The route reflectors are configured with the bgp cluster-id command. What is the primary purpose of this command?

A service provider is implementing MPLS Traffic Engineering (TE) with RSVP-TE in its core network. The network engineer wants to ensure that TE tunnels are established with the most efficient path and that they can be rerouted quickly in case of a link failure. Which protocol is used by RSVP-TE to distribute TE link attributes and topology information?

A service provider is deploying MPLS L3VPN services across its core. The PE routers are Cisco ASR 9000 series running Cisco IOS XR. The design requires that customer VPN routes be advertised between PE routers without requiring a full mesh of iBGP sessions. The network architect wants to use BGP route reflectors (RRs) to scale the VPNv4 route distribution. Which BGP address family must be configured on the RR to carry VPNv4 routes?

A service provider is implementing Segment Routing (SR) with MPLS data plane in its core network. The network uses IS-IS as the IGP. The engineer must configure the routers to support SR and ensure that MPLS forwarding is enabled on all core interfaces. Which two configuration tasks are required on each router to enable SR-MPLS with IS-IS? (Choose two.)

A network engineer is configuring OSPF on a Cisco IOS XR router in a service provider core. The router is connected to multiple areas, and the engineer wants to summarize routes from Area 1 into Area 0. Which command should be used to configure inter-area route summarization on the Area Border Router (ABR)?

A service provider is deploying MPLS L3VPN services. The PE routers are Cisco ASR 9000 running IOS XR. The network engineer must ensure that customer VPN routes are imported into the correct VRF based on the route target (RT) extended community. Which BGP attribute is used to carry the route target extended community in VPNv4 updates?