Senior management wants you to evaluate the risks to your network of offering VPWS, VPLS, GRE, or other tunneling services to your fiber-connected client base.
Clients indicate that they prefer to use Layer 2 switches as CEs.
Which two tunneling services expose your network to minimal risk and meet the clients' needs, including separation between providers and customer networks? (Choose two.)
Click on the arrows to vote for the correct answer
A. B. C. D. E.AE.
VPWS (Virtual Private Wire Service) and VPLS (Virtual Private LAN Service) are Layer 2 tunneling technologies used for providing virtual private networks ( VPNs) to customers. These services allow customers to extend their LANs over a service provider's network, enabling them to connect geographically dispersed sites as if they were on the same LAN. On the other hand, GRE (Generic Routing Encapsulation) is a Layer 3 tunneling protocol used for encapsulating and carrying a wide variety of network layer protocols over an IP network.
To evaluate the risks of offering tunneling services to customers, we need to consider several factors, such as security, scalability, complexity, and operational overhead. In this scenario, the senior management wants to minimize the risks while meeting the clients' needs for Layer 2 switches as CEs. Based on these requirements, the two tunneling services that expose the network to minimal risk and meet the clients' needs are VPWS and 802.1Q.
VPWS is a point-to-point Layer 2 VPN service that provides a secure and scalable solution for connecting two customer sites over a service provider's network. With VPWS, each customer site has its own virtual circuit (VC) that is isolated from other customers' traffic, ensuring separation between providers and customer networks. VPWS is a mature and widely deployed technology that supports multiple encapsulation options, including MPLS and Ethernet, making it flexible and interoperable with various CE devices.
802.1Q, also known as VLAN tagging, is a Layer 2 tunneling technology that enables multiple virtual LANs (VLANs) to be carried over a single physical link. 802.1Q uses a 4-byte tag inserted into the Ethernet frame header to identify the VLAN ID of the frame. With 802.1Q, customers can create their own VLANs and extend them over a service provider's network, allowing them to achieve network segmentation and isolation. 802.1Q is a simple and widely supported technology that can be easily implemented on most CE devices, making it a popular choice for customers.
In contrast, GRE and QinQ are not suitable options for this scenario. GRE is a Layer 3 tunneling protocol that provides a more complex and less secure solution than VPWS and 802.1Q. GRE does not provide any inherent security features and requires additional measures, such as IPsec encryption and authentication, to secure the tunnel. Moreover, GRE is not well-suited for carrying Layer 2 traffic, which is the primary requirement of the customers in this scenario.
QinQ, also known as double-tagging, is a Layer 2 tunneling technology that enables multiple VLANs to be carried over a single physical link by adding an additional VLAN tag to the Ethernet frame header. While QinQ can provide some level of VLAN isolation, it has several limitations, such as limited scalability, increased complexity, and lack of interoperability with some CE devices. Therefore, QinQ is not a suitable option for this scenario, as it does not meet the clients' needs for using Layer 2 switches as CEs and exposes the network to more risk than VPWS and 802.1Q.
In conclusion, the two tunneling services that expose the network to minimal risk and meet the clients' needs, including separation between providers and customer networks, are VPWS and 802.1Q. These services provide secure, scalable, and interoperable solutions for extending Layer 2 networks over a service provider's network, while minimizing the risks associated with tunneling.