Back to IPv6

Multicast

5 minutes 5 Questions

Multicast is a key feature in IPv6 that allows a single source to send data to multiple destinations simultaneously. In contrast to IPv4, which uses broadcast addresses for this function, IPv6 eliminates the concept of broadcast and relies on multicast addresses for one-to-many or many-to-many comm…

Test mode:
Start practice test
CompTIA Network+ - Multicast Example Questions

Test your knowledge of Multicast

Question 1

You are tasked with deploying an IP phone system in your organization that uses multicast for call signaling. Some users report they don't receive calls. What's the most likely cause of the problem?

Correct Answer: The users' phones are not configured to join the multicast group

The best answer is that the users' phones are not configured to join the multicast group. A multicast message is sent to a group of devices simultaneously. In order to receive multicast call signaling, the user's IP phones must be configured to join the appropriate multicast group. If they are not, then they will not receive these messages, which could be why they are not receiving calls. The other answers are not the most likely causes: a malfunctioning IP phone system would likely affect all users, not just some; the question tells us that the system uses multicast, not unicast, communication; and outdated firmware could cause a variety of issues, but without more information, it is not the most likely cause of this specific problem.

Question 2

Your organization uses a multicast streaming service for its employees in different locations. One of the locations reports buffering and lagging issues. What should you do to improve the streaming quality?

Correct Answer: Deploy an additional multicast server closer to the affected location

Deploying an additional multicast server closer to the affected location is the best solution because it reduces the distance data has to travel, thus reducing latency and the likelihood of buffering issues. As for the other options: increasing the video streaming resolution can actually make the problem worse by requiring more data to be transmitted, potentially increasing lag; implementing a VLAN for the streaming traffic may help with network organization but doesn't directly address the issue of buffering and lag; switching to unicast streaming is not an optimal solution as it does not scale well for large numbers of viewers, making it a poor choice for an organization with numerous remote employees.

Question 3

A multicast group is added to your network to broadcast security camera feeds. Users on a specific VLAN can't access the multicast feed. What's the best solution to troubleshoot this issue?

Correct Answer: Enable IGMP Snooping on the switch for the VLAN

Enabling IGMP (Internet Group Management Protocol) Snooping on the switch for the VLAN is the best solution for the presented situation. IGMP snooping enhances multicast efficiency by preventing flooding of multicast traffic, restricting it to only the ports that have members of a certain multicast group. This helps multicast groups function effectively on VLAN, facilitating access to the security camera feeds. The other options are incorrect: rebooting the security cameras doesn't address a potential network configuration problem; configuring multicast group restrictions could potentially exclude certain users and wouldn't solve the issue at hand; placing users on a different VLAN wouldn't necessarily provide access to multicast group and would also likely incur more configuration complications.

More Multicast questions
10 questions (total)
Start 10 question test