Explanation:
The correct answer is b. Virtual Private LAN Service (VPLS).
VPLS is a Layer 2 VPN technology that extends a virtual LAN across multiple locations, allowing connected devices to communicate as if they were on the same physical LAN. This technology is particularly useful for organizations with multiple geographically dispersed sites that require seamless communication between them. MPLS VPN (option a) typically operates at Layer 3 and provides secure connectivity between different sites but does not create a virtual LAN. Layer 2 VPN (option c) and Layer 3 VPN (option d) are different types of VPN technologies that do not specifically focus on creating virtual LANs across multiple locations.

Explanation:
The correct answer is b. Multiprotocol Label Switching (MPLS).
MPLS is a routing technique used in telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, which significantly improves forwarding efficiency. It is commonly employed in service provider networks to provide traffic engineering, VPN services, and quality of service (QoS) mechanisms. Cisco IOS XR Software (option a) is an operating system used in high-end Cisco routers, including those that support MPLS. Any Transport over MPLS (AToM) (option c) is a technology used to transport Layer 2 packets over an MPLS network. The Cisco ASR 9000 Series routers (option d) are often used in MPLS deployments, but MPLS itself is the technology primarily responsible for efficient routing and forwarding of labeled packets.

Explanation:
The correct answer is a. Inter-AS MPLS VPNs.
Inter-AS MPLS VPNs are designed to connect multiple customer sites across different autonomous systems (AS) while maintaining separate routing domains for each customer. This technology allows service providers to offer VPN services to customers with geographically dispersed sites or multiple AS boundaries. Virtual Private LAN Service (VPLS) (option b) extends a virtual LAN across multiple locations but does not inherently maintain separate routing domains. Carrier Supporting Carrier (CsC) VPN (option c) is a type of VPN where one service provider acts as the carrier for another service provider’s VPN traffic. EVPN (Ethernet VPN) (option d) is a technology used for building Layer 2 VPNs over MPLS networks but does not necessarily maintain separate routing domains.

Explanation:
The correct answer is a. MPLS (Multiprotocol Label Switching) VPN.
MPLS VPN is a widely used technology in service provider networks for creating secure and scalable virtual private networks. It operates at Layer 3 of the OSI model and utilizes label-switched paths to route and forward packets between different sites, ensuring privacy and security. Layer 2 VPN (option b) extends Layer 2 connectivity between sites but does not provide the same level of scalability and security as MPLS VPN. Layer 3 VPN (option c) also offers secure connectivity between sites but typically relies on IP routing rather than label-switching. Any Transport over MPLS (AToM) (option d) is a technology that enables the transport of Layer 2 traffic over an MPLS network but is not specifically designed for creating VPNs.

Explanation:
The correct answer is b. Simplified network management and provisioning.
One of the key advantages of MPLS VPN services is simplified network management and provisioning. MPLS VPNs provide a centralized control plane for configuring and managing VPN connectivity, making it easier for network administrators to provision new services, troubleshoot issues, and optimize network performance. While MPLS VPNs offer enhanced security features such as traffic separation and isolation, encryption of data packets (option a) is typically implemented at higher protocol layers and is not a direct feature of MPLS VPN. MPLS can help reduce latency (option c) by providing efficient traffic engineering mechanisms, but it does not inherently guarantee reduced latency for all applications. MPLS VPNs are also highly scalable (option d), but simplified network management and provisioning are often cited as the primary advantage in service provider environments.

Explanation:
The correct answer is b. Layer 2 VPN (L2VPN).
Layer 2 VPN (L2VPN) is commonly used in MPLS VPN deployments to transport Layer 2 frames over an MPLS network. L2VPN technologies, such as Virtual Private LAN Service (VPLS) and Ethernet over MPLS (EoMPLS), enable service providers to extend Layer 2 connectivity between customer sites over an MPLS backbone. BGP/MPLS Layer 3 VPN with IPv6 (option a) is a different type of VPN technology that focuses on Layer 3 connectivity. Carrier Ethernet Services over MPLS (CEM) (option c) is a method of delivering Ethernet services over an MPLS network but is not specific to transporting Layer 2 frames between sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments but do not specifically address the transport of Layer 2 frames.

Explanation:
The correct answer is b. Virtual Private LAN Service (VPLS).
VPLS is specifically designed to extend a customer’s Layer 2 broadcast domain across multiple sites in a service provider network. It allows different customer sites to appear as if they are connected to the same LAN, facilitating seamless communication between them. MPLS VPN (option a) provides Layer 3 connectivity between sites and does not extend Layer 2 broadcast domains. Layer 2 VPN (option c) and Layer 3 VPN (option d) are general categories of VPN technologies that do not specifically focus on extending Layer 2 broadcast domains.

Explanation:
The correct answer is a. Cisco ASR 9000 Series Aggregation Services Routers.
The Cisco ASR 9000 Series routers are widely deployed by service providers for implementing MPLS VPN services due to their high-performance capabilities, scalability, and carrier-grade reliability. These routers are designed to handle the demanding requirements of large-scale MPLS VPN deployments, making them a popular choice among service providers. While Cisco IOS XR Software (option b) is the operating system used in ASR 9000 Series routers, it is the hardware platform itself that is specifically optimized for MPLS VPN services. Cisco IOS XE Software (option c) is used in other router series and may also support MPLS VPN functionality, but the ASR 9000 Series is the most common choice for large-scale deployments. The Cisco CRS Router Series (option d) is another high-end router series used in service provider networks, but it is not as commonly associated with MPLS VPN services as the ASR 9000 Series.

Explanation:
The correct answer is b. Layer 2 VPN (L2VPN).
Layer 2 VPN (L2VPN) technology is used to transport Layer 2 frames over an MPLS infrastructure. L2VPN solutions, such as Virtual Private LAN Service (VPLS) and Ethernet over MPLS (EoMPLS), allow service providers to extend Layer 2 connectivity between customer sites over an MPLS backbone. BGP/MPLS Layer 3 VPN with IPv6 (option a) is a different type of VPN technology that focuses on Layer 3 connectivity and does not transport Layer 2 frames directly. Carrier Ethernet Services over MPLS (CEM) (option c) is a method of delivering Ethernet services over an MPLS network but does not specifically transport Layer 2 frames between sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments but do not directly address the transport of Layer 2 frames.

Explanation:
The correct answer is a. Inter-AS MPLS VPNs.
Inter-AS MPLS VPNs are designed to connect multiple customer sites across different autonomous systems (AS) while maintaining separate routing domains for each customer. This technology allows service providers to offer VPN services to customers with geographically dispersed sites or multiple AS boundaries. Virtual Private LAN Service (VPLS) (option b) extends a virtual LAN across multiple locations but does not inherently maintain separate routing domains. Carrier Supporting Carrier (CsC) VPN (option c) is a type of VPN where one service provider acts as the carrier for another service provider’s VPN traffic. EVPN (Ethernet VPN) (option d) is a technology used for building Layer 2 VPNs over MPLS networks but does not necessarily maintain separate routing domains.

Explanation:
The correct answer is c. Any Transport over MPLS (AToM).
Any Transport over MPLS (AToM) is a technology used to transport Layer 2 frames between customer sites over an MPLS backbone without the need for MPLS forwarding. AToM creates pseudowires that emulate point-to-point or point-to-multipoint connections over the MPLS network, enabling seamless transport of Layer 2 traffic. Layer 2 VPN (L2VPN) (option a) and Inter-AS MPLS VPNs (option d) also transport Layer 2 frames over MPLS networks but may utilize MPLS forwarding. BGP/MPLS Layer 3 VPN with IPv6 (option b) is a different type of VPN technology that focuses on Layer 3 connectivity rather than Layer 2 transport.

Explanation:
The correct answer is b. MPLS VPNs use label-switching to forward packets.
MPLS VPNs distinguish themselves from traditional IP-based VPNs by using label-switching to forward packets instead of relying solely on destination IP addresses for routing decisions. MPLS labels are assigned to packets at the ingress router and used to determine the next hop along the label-switched path (LSP) to the egress router, improving forwarding efficiency and enabling traffic engineering. MPLS VPNs support both point-to-point and multipoint-to-multipoint connections (option a) and do not require dedicated physical connections between sites (option c). Additionally, MPLS VPNs operate at the network layer (Layer 3) of the OSI model, not the application layer (option d).

Explanation:
The correct answer is c. Layer 3 VPN (L3VPN).
Layer 3 VPN (L3VPN) technology is commonly used in MPLS VPN deployments to provide Layer 3 connectivity between customer sites. L3VPN solutions use MPLS label-switched paths (LSPs) to route IP packets between sites, allowing customers to communicate over a shared MPLS infrastructure while maintaining separate routing domains. Virtual Private LAN Service (VPLS) (option a) provides Layer 2 connectivity between sites, not Layer 3. Any Transport over MPLS (AToM) (option b) is used for transporting Layer 2 frames over MPLS networks. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments and can support both Layer 2 and Layer 3 connectivity.

Explanation:
The correct answer is b. Virtual Private LAN Service (VPLS).
VPLS is commonly used in service provider networks to provide Layer 2 connectivity between customer sites over an MPLS backbone. It enables the creation of a virtual LAN that spans multiple locations, allowing connected devices to communicate as if they were on the same LAN segment. BGP/MPLS Layer 3 VPN with IPv6 (option a) is a different type of VPN technology that focuses on Layer 3 connectivity rather than Layer 2. Carrier Ethernet Services over MPLS (CEM) (option c) is a method of delivering Ethernet services over an MPLS network but is not specifically designed for providing Layer 2 connectivity between customer sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments and can support both Layer 2 and Layer 3 connectivity.

Explanation:
The correct answer is c. Enabling the creation of secure and scalable virtual private networks.
MPLS VPN technology in a service provider network primarily focuses on creating secure and scalable virtual private networks (VPNs) by leveraging multiprotocol label switching (MPLS) to route and forward packets between different sites. It provides a mechanism for separating customer traffic and ensuring privacy and security while allowing for efficient traffic engineering and scalability. While MPLS VPNs may offer some level of encryption for data privacy, encryption itself is not the primary function of MPLS VPN technology (option a). Extending Layer 2 broadcast domains between customer sites is typically associated with technologies like Virtual Private LAN Service (VPLS) rather than MPLS VPNs (option b). Prioritizing traffic based on quality of service (QoS) requirements (option d) is an additional feature that MPLS VPNs can support but is not their primary function.

Explanation:
The correct answer is a. MPLS (Multiprotocol Label Switching) VPN.
MPLS VPN technology allows service providers to offer VPN services to customers with geographically dispersed sites while maintaining separate routing domains for each customer. MPLS VPNs use label-switching to route packets between different sites, providing a secure and scalable solution for connecting multiple customer locations over a shared infrastructure. Carrier Supporting Carrier (CsC) VPN (option b) involves one service provider acting as the carrier for another service provider’s VPN traffic and does not inherently maintain separate routing domains. Layer 2 VPN (L2VPN) (option c) and Inter-AS MPLS VPNs (option d) are different types of VPN technologies that may not provide the same level of separation between customer routing domains as MPLS VPNs.

Explanation:
The correct answer is b. Layer 2 VPN (L2VPN).
Layer 2 VPN (L2VPN) technology is commonly used in MPLS VPN deployments to enable the transport of Layer 2 frames between customer sites over an MPLS backbone. L2VPN solutions, such as Virtual Private LAN Service (VPLS) and Ethernet over MPLS (EoMPLS), allow service providers to extend Layer 2 connectivity between customer sites over an MPLS infrastructure. BGP/MPLS Layer 3 VPN with IPv6 (option a) is a different type of VPN technology that focuses on Layer 3 connectivity rather than Layer 2 transport. Carrier Ethernet Services over MPLS (CEM) (option c) is a method of delivering Ethernet services over an MPLS network but is not specifically designed for transporting Layer 2 frames between sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments but may not specifically address the transport of Layer 2 frames.

Explanation:
The correct answer is a. To enable communication between different autonomous systems using MPLS VPN technology.
Inter-AS MPLS VPNs are designed to enable communication between customer sites located in different autonomous systems (AS) using MPLS VPN technology. They allow service providers to extend VPN services across multiple AS boundaries while maintaining separate routing domains for each customer. This is particularly useful for large-scale networks with complex routing requirements that span multiple AS boundaries. Extending Layer 2 broadcast domains (option b) is typically associated with technologies like Virtual Private LAN Service (VPLS) rather than Inter-AS MPLS VPNs. Providing Layer 3 connectivity (option c) and prioritizing traffic based on QoS requirements (option d) are functions that can be achieved using MPLS VPN technology but are not specific to Inter-AS deployments.

Explanation:
The correct answer is c. Layer 3 VPN (L3VPN).
Layer 3 VPN (L3VPN) technology is commonly used in MPLS VPN deployments to provide secure and scalable Layer 3 connectivity between customer sites. L3VPN solutions use MPLS label-switched paths (LSPs) to route IP packets between sites, allowing customers to communicate over a shared MPLS infrastructure while maintaining separate routing domains. Virtual Private LAN Service (VPLS) (option a) provides Layer 2 connectivity between sites, not Layer 3. Layer 2 VPN (L2VPN) (option b) is another type of VPN technology that focuses on extending Layer 2 connectivity between customer sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments and can support both Layer 2 and Layer 3 connectivity, but they are not specifically designed for providing Layer 3 connectivity between customer sites.

Explanation:
The correct answer is b. Layer 2 VPN (L2VPN).
Layer 2 VPN (L2VPN) technology is commonly used in MPLS VPN deployments to transport Layer 2 frames between customer sites over an MPLS backbone. L2VPN solutions, such as Virtual Private LAN Service (VPLS) and Ethernet over MPLS (EoMPLS), allow service providers to extend Layer 2 connectivity between customer sites over an MPLS infrastructure. BGP/MPLS Layer 3 VPN with IPv6 (option a) is a different type of VPN technology that focuses on Layer 3 connectivity rather than Layer 2 transport. Carrier Ethernet Services over MPLS (CEM) (option c) is a method of delivering Ethernet services over an MPLS network but is not specifically designed for transporting Layer 2 frames between sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments but may not specifically address the transport of Layer 2 frames.

Explanation:
The correct answer is a. MPLS (Multiprotocol Label Switching) VPN.
MPLS VPN technology allows service providers to offer VPN services to customers with geographically dispersed sites while maintaining separate routing domains for each customer. MPLS VPNs use label-switching to route packets between different sites, providing a secure and scalable solution for connecting multiple customer locations over a shared infrastructure. Carrier Supporting Carrier (CsC) VPN (option b) involves one service provider acting as the carrier for another service provider’s VPN traffic and does not inherently maintain separate routing domains. Layer 2 VPN (L2VPN) (option c) and Inter-AS MPLS VPNs (option d) are different types of VPN technologies that may not provide the same level of separation between customer routing domains as MPLS VPNs.

Explanation:
The correct answer is a. To enable communication between different autonomous systems using MPLS VPN technology.
Inter-AS MPLS VPNs are designed to enable communication between customer sites located in different autonomous systems (AS) using MPLS VPN technology. They allow service providers to extend VPN services across multiple AS boundaries while maintaining separate routing domains for each customer. This is particularly useful for large-scale networks with complex routing requirements that span multiple AS boundaries. Extending Layer 2 broadcast domains (option b) is typically associated with technologies like Virtual Private LAN Service (VPLS) rather than Inter-AS MPLS VPNs. Providing Layer 3 connectivity (option c) and prioritizing traffic based on QoS requirements (option d) are functions that can be achieved using MPLS VPN technology but are not specific to Inter-AS deployments.

Explanation:
The correct answer is a. Virtual Private LAN Service (VPLS).
VPLS allows a service provider to provide Layer 2 connectivity between customer sites over an MPLS backbone. It extends a virtual LAN across multiple locations, allowing connected devices to communicate as if they were on the same LAN segment. Layer 3 VPN (L3VPN) (option b) provides Layer 3 connectivity between customer sites, while Carrier Ethernet Services over MPLS (CEM) (option c) is used to deliver Ethernet services over an MPLS network. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments and may support both Layer 2 and Layer 3 connectivity, but they are not specifically designed for providing Layer 2 connectivity between customer sites.

Explanation:
The correct answer is a. Layer 2 VPN (L2VPN).
Layer 2 VPN (L2VPN) technology enables the transport of Layer 2 frames between customer sites over an MPLS backbone. L2VPN solutions, such as Virtual Private LAN Service (VPLS) and Ethernet over MPLS (EoMPLS), allow service providers to extend Layer 2 connectivity between customer sites over an MPLS infrastructure. BGP/MPLS Layer 3 VPN with IPv6 (option b) is a different type of VPN technology that focuses on Layer 3 connectivity rather than Layer 2 transport. Inter-AS MPLS VPNs (option c) are used to connect multiple autonomous systems in MPLS VPN deployments and may support both Layer 2 and Layer 3 connectivity, but they are not specifically designed for transporting Layer 2 frames. Any Transport over MPLS (AToM) (option d) is a technology used to transport Layer 2 traffic over an MPLS network but may not specifically address MPLS VPN deployments.

Explanation:
The correct answer is c. Layer 3 VPN (L3VPN).
Layer 3 VPN (L3VPN) technology is commonly used in MPLS VPN deployments to provide secure and scalable Layer 3 connectivity between customer sites. L3VPN solutions use MPLS label-switched paths (LSPs) to route IP packets between sites, allowing customers to communicate over a shared MPLS infrastructure while maintaining separate routing domains. Virtual Private LAN Service (VPLS) (option a) provides Layer 2 connectivity between sites, not Layer 3. Layer 2 VPN (L2VPN) (option b) is another type of VPN technology that focuses on extending Layer 2 connectivity between customer sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments and can support both Layer 2 and Layer 3 connectivity, but they are not specifically designed for providing Layer 3 connectivity between customer sites.

Explanation:
The correct answer is b. Inter-AS MPLS VPNs.
Inter-AS MPLS VPNs are used to enable communication between customer sites located in different autonomous systems (AS) using MPLS VPN technology. They allow service providers to extend VPN services across multiple AS boundaries while maintaining separate routing domains for each customer. Virtual Private LAN Service (VPLS) (option a) provides Layer 2 connectivity between sites but is not specifically designed for inter-AS communication. Layer 2 VPN (L2VPN) (option c) provides Layer 2 connectivity but does not inherently address inter-AS communication. Carrier Ethernet Services over MPLS (CEM) (option d) is used to deliver Ethernet services over an MPLS network but is not specifically designed for inter-AS MPLS VPN deployments.

Explanation:
The correct answer is b. Virtual Private LAN Service (VPLS).
VPLS allows a service provider to extend a virtual LAN across multiple locations in an MPLS network. It enables Layer 2 connectivity between customer sites, allowing devices in different locations to communicate as if they were on the same LAN segment. MPLS VPN (option a) provides secure and scalable virtual private networks but does not specifically extend Layer 2 connectivity across multiple locations. Layer 2 VPN (L2VPN) (option c) is a generic term for VPN technologies that provide Layer 2 connectivity but does not inherently extend virtual LANs. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments but are not specifically designed for extending virtual LANs.

Explanation:
The correct answer is b. Layer 2 VPN (L2VPN).
Layer 2 VPN (L2VPN) technology is commonly used in MPLS VPN deployments to transport Layer 2 frames between customer sites over an MPLS backbone. L2VPN solutions, such as Virtual Private LAN Service (VPLS) and Ethernet over MPLS (EoMPLS), allow service providers to extend Layer 2 connectivity between customer sites over an MPLS infrastructure. BGP/MPLS Layer 3 VPN with IPv6 (option a) is a different type of VPN technology that focuses on Layer 3 connectivity rather than Layer 2 transport. Carrier Ethernet Services over MPLS (CEM) (option c) is a method of delivering Ethernet services over an MPLS network but is not specifically designed for transporting Layer 2 frames between sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments but may not specifically address the transport of Layer 2 frames.

Explanation:
The correct answer is a. MPLS (Multiprotocol Label Switching) VPN.
MPLS VPN technology allows service providers to offer VPN services to customers with geographically dispersed sites while maintaining separate routing domains for each customer. MPLS VPNs use label-switching to route packets between different sites, providing a secure and scalable solution for connecting multiple customer locations over a shared infrastructure. Carrier Supporting Carrier (CsC) VPN (option b) involves one service provider acting as the carrier for another service provider’s VPN traffic and does not inherently maintain separate routing domains. Layer 2 VPN (L2VPN) (option c) and Inter-AS MPLS VPNs (option d) are different types of VPN technologies that may not provide the same level of separation between customer routing domains as MPLS VPNs.

Explanation:
The correct answer is c. Layer 3 VPN (L3VPN).
Layer 3 VPN (L3VPN) technology is commonly used in MPLS VPN deployments to provide secure and scalable Layer 3 connectivity between customer sites. L3VPN solutions use MPLS label-switched paths (LSPs) to route IP packets between sites, allowing customers to communicate over a shared MPLS infrastructure while maintaining separate routing domains. Virtual Private LAN Service (VPLS) (option a) provides Layer 2 connectivity between sites, not Layer 3. Layer 2 VPN (L2VPN) (option b) is another type of VPN technology that focuses on extending Layer 2 connectivity between customer sites. Inter-AS MPLS VPNs (option d) are used to connect multiple autonomous systems in MPLS VPN deployments and can support both Layer 2 and Layer 3 connectivity, but they are not specifically designed for providing Layer 3 connectivity between customer sites.