CompTIA Network+ Question C-79

The network install is failing redundancy testing at the MDF. The traffic being transported is a mixture of multicast and unicast signals. Which of the following would BEST handle the rerouting caused by the disruption of service?

A. Layer 3 switch
B. Proxy server
C. Layer 2 switch
D. Smart hub

Correct Answer: A

Explanation:
The question states that the traffic being transported is a mixture of multicast and unicast signals. There are three basic types of network transmissions: broadcasts, which are packets transmitted to every node on the network; unicasts, which are packets transmitted to just one node; and multicasts, which are packets transmitted to a group of nodes. Multicast is a layer 3 feature of IPv4 & IPv6. Therefore, we would need a layer 3 switch (or a router) to reroute the traffic. Unlike layer 2 switches that can only read the contents of the data-link layer protocol header in the packets they process, layer 3 switches can read the (IP) addresses in the network layer protocol header as well.

CompTIA Network+ Question A-69

A technician needs to limit the amount of broadcast traffic on a network and allow different segments to communicate with each other. Which of the following options would satisfy these requirements?

A. Add a router and enable OSPF.
B. Add a layer 3 switch and create a VLAN.
C. Add a bridge between two switches.
D. Add a firewall and implement proper ACL.

Correct Answer: B

Explanation:
We can limit the amount of broadcast traffic on a switched network by dividing the computers into logical network segments called VLANs.
A virtual local area network (VLAN) is a logical group of computers that appear to be on the same LAN even if they are on separate IP subnets. These logical subnets are configured in the network switches. Each VLAN is a broadcast domain meaning that only computers within the same VLAN will receive broadcast traffic.
To allow different segments (VLAN) to communicate with each other, a router is required to establish a connection between the systems. We can use a network router to route between the VLANs or we can use a ‘Layer 3’ switch. Unlike layer 2 switches that can only read the contents of the data-link layer protocol header in the packets they process, layer 3 switches can read the (IP) addresses in the network layer protocol header as well.