Virtual Switches

Correct Answer: Enable trunking on the virtual switch and configure VLAN tagging on the virtual machines

To configure a virtual switch to support multiple VLANs for a group of virtual machines, you should 'Enable trunking on the virtual switch and configure VLAN tagging on the virtual machines'. Trunking allows network devices to carry traffic from multiple VLANs over the same link, and VLAN tagging can identify which VLAN a certain packet belongs to in a mixed traffic environment. Now including the other options, 'Enable port mirroring on the virtual switch' is incorrect as port mirroring is a method of copying and sending network packets transmitted or received through a port to a port on a monitoring device. This doesn't support multiple VLANs. The option 'Configure each virtual machine to use a separate virtual switch' might be theoretically possible but it is impractical in terms of efficiency and scalability. And finally, 'Disallow VLANs on the virtual switch' is completely against what is aimed to be achieved. Therefore, it's incorrect.

Correct Answer: Check the VM's virtual network card configuration

The best course of action when a user is complaining about poor network performance between a VM and a physical device would be to 'Check the VM's virtual network card configuration'. If the VM's network card is not set up correctly, this can cause performance issues. Restarting all the virtual switches might cause unnecessary downtime for other users. Disabling all VLANs on the virtual switches would not necessarily improve network performance and could lead to other issues due to the loss of VLAN benefits such as logical grouping of network nodes and increased security. Forcing a different duplex setting for the physical network card might not solve the problem if the issue is with the VM's virtual network card configuration.

Correct Answer: Enable IGMP snooping

The best solution to high levels of multicast traffic would be to 'Enable IGMP snooping', because IGMP snooping allows the switch to recognize and manage such multicast traffic, reducing unnecessary load on portions of the network not interested in that traffic. 'Disable multicast entirely' is not typically possible or practical, as multicast is a fundamental aspect of how networks operate. 'Create multiple VLANs to segregate traffic' would not solve the issue; rather, it would just distribute the traffic across multiple networks, potentially causing network congestion on all of them. Lastly, 'Increase the bandwidth of the virtual switch' would still not efficiently manage the multicast traffic because it doesn't address the core problem of controlling and managing the traffic.