IT Network+ Chapter 3

Under STP, if a host port is working as normal, what state is it in?

Forwarding.

What is the function of a network controller?

Implements the polices defined by software defined networking (SDN) control applications by interfacing with the configuration interfaces of network appliances.

How does a switch keep track of the hardware addresses of hosts connected to its ports?

It uses a MAC address table stored in content addressable memory (CAM).

What is a WLAN?

Wireless Local Area Network.

What types of devices are connected in a PAN?

A personal area network (PAN) links devices such as laptops and smartphones and provides connectivity with peripheral devices (printers, input devices, headsets, and so on) plus wearable technology, such as fitness trackers and smart watches.

What is the purpose of a SAN?

A storage area network (SAN) links together different kinds of storage devices (RAID array, hard disks, SSDs, tape drives, and so on) and makes "pools" of storage capacity available to servers.

What four layers can be used to conceptualize distributed switching hierarchy?

Access, distribution, core, and data center.

What type of device is used to implement a physical star topology?

Any type of node that connects multiple devices over multiple ports, including hubs, bridges, switches, and routers.

Assuming the switches are configured with suitable protocols, what would determine which switch became the root bridge? How could this be changed to ensure that the main switch was root?

By default, the switch with the lowest MAC address would become the root, unless a priority has been set on one or several switches, when the switch with the lowest priority number would win the election.

What mechanisms protect the switching infrastructure from malicious STP traffic?

Configuration settings such as BPDU Guard and BPDU Filter prevent hosts from injecting bridge protocol data units (BPDUs) into the network. Root guard prevents devices from attempting to become root.

What is microsegmentation?

Each switch port creates a separate collision domain for each attached host, essentially eliminating the effect of collisions on network performance and allowing each host exclusive use of the full media bandwidth.

True or False? A bridge does not forward broadcast or multicast traffic.

False. Segments on different bridge ports are in separate collision domains but the same broadcast domain.

True or False? Devices can only transmit on an Ethernet network when the media is clear, and the opportunity to transmit becomes less frequent as more devices are added. Also, the probability of collisions increases. These problems can be overcome by installing a hub.

False. The description of the problem is true, but the solution is not. This issue is resolved by using a bridge or (more likely these days) a switch.

What is happening if a switch is flooding?

It is sending frames out on all ports (other than the source port). This typically happens when it is learning MAC addresses or forwarding broadcast traffic.

Identify the physical network topology depicted in the following graphic. a. Star b. Bus c. Mesh d. Ring

Mesh

What network infrastructure implementation is larger than a LAN but smaller than a WAN?

Metropolitan area network (MAN). You could also mention campus area network (CAN).

What term is used to describe a topology in which two nodes share a single link?

Point-to-point.

What is PoE?

Power over Ethernet is an IEEE specification for delivering power to devices from switch ports over network cabling.

What is the function of STP?

Spanning tree Protocol (STP) prevents switching loops. A switching loop is where flooded traffic is continually looped around a network with redundant links between switches.

Looking at this design, what are its potential weaknesses and strengths?

Strengths: multiple links to the router for resilience, and switch link speeds increase as you go towards the core switch. Weaknesses: no resilience in the case of link failure, and a whole floor could be isolated with a single cable disconnect.

What is characteristic of the bandwidth of a bus topology?

The bandwidth is shared between all nodes connected to the bus.

What would Janice need to ensure about the configuration of the switches, given the revised network layout?

They would need to support the Spanning Tree Protocol; otherwise broadcast storms will occur and the switch's MAC address tables will be constantly updating.

Given this design and assuming all switch connections were in place. how many links would be placed in a blocking state by the STP algorithm?

Three- That would be the minimum number of links that would need to be blocking to ensure loops were not formed. The blocks could be positioned between the floor 1 and floor 2 switch, between the floor 2 and floor 3 switch, and the floor 2 extension switch and floor 3 extension switch for example.

You need operations to continue if one link fails. How many links does it take to connect three sites?

Three.

True or False? Switch ports should normally be set to autonegotiate speed and duplex settings.

True; the speed/duplex setting rarely needs to be manually configured on modern networks.

If you connect two hubs with a crossover cable, are nodes connected to either hub in the same Collision domain?

Yes.