Network Virtualization

Correct Answer: Private VLANs

The option 'Private VLANs' is the correct answer. Private VLANs (PVLANs) provide the ability to isolate hosts at the data link layer (Layer 2) of the OSI model. Using PVLANs can prevent a VM from communicating directly with other systems within the same physical network, including systems outside of the corporate firewall, thus securing sensitive data from exposure. The other answers are incorrect because: 'Port Mirroring' is a method used to monitor network traffic which can't isolate a VM. 'Link Aggregation' combines multiple network connections in parallel to increase throughput and provide redundancy, but it does not provide any form of network isolation. Finally, 'Traffic Shaping' is a technique designed to control the volume of traffic being sent over a network and to prevent overwhelming a network device which also doesn't offer network isolation for a VM.

Correct Answer: Virtual NIC Offloading

The most effective method to increase inter-VM network performance is the process of 'Virtual NIC Offloading'. This is because it delegates the networking processing task which is normally done by the CPU, to the network card. This reduces CPU workload, and can significantly improve network performance since the CPU can spend more time on other tasks. Consequently, the network becomes more efficient and faster, which can greatly increase the performance of inter-VM communication. On the other hand, 'Jumbo Frames', 'Query of Service (QoS)', and 'Multipathing' could also be considered as methods to increase network performance. However, they are not the best solutions to increase inter-VM network performance. 'Jumbo Frames' increase the payload size of each network packet and can improve network efficiency, but they require network hardware support and can lead to greater latency. 'Quality of Service (QoS)' is a method of prioritizing specific network traffic over others, but doesn't necessarily increase the overall network performance, it just prioritizes the use of available resources. Lastly, 'Multipathing' is a technique for redundancy and load balancing in network connections, but doesn’t directly increase network performance. Therefore, these methods would not have as significant of an impact as 'Virtual NIC Offloading'.

Correct Answer: Network Interface Card (NIC) Teaming

The best technique for a company to increase redundancy and performance for their virtualized server environment is Network Interface Card (NIC) Teaming. NIC Teaming, also known as load balancing and failover (LBFO), allows multiple network adapters to be placed into a team for the purposes of bandwidth aggregation, and traffic failover to maintain connectivity in the event of a network component failure. This increases both performance (as traffic is load-balanced across multiple network cards) and redundancy (as if one network card fails, the other can take over). On the other hand, Static Routing, Access Control Lists (ACLs), and Port Spanning are not primarily used to increase redundancy and performance. Static Routing is used to manually configure routes in a network, Access Control Lists (ACLs) is a concept used in providing network security, and Port Spanning (or Port Trunking) allows you to combine multiple physical ports into a single logical port, it does provide redundancy but lacks the increased performance provided by NIC Teaming.