IT315 Ethernet: Learning Check

There is only a single possible path between hosts on an Ethernet LAN. What does this mean for the switches on that LAN?

A given MAC address on the LAN appears only once in any switching table.

Which of the following should you consider when designing a large wireless network with more than three access points?

All of the above are considerations when designing large wireless networks.

Which of the following incorrectly describes the role of an Access Point in an Ethernet network?

All of the above are correct about the role of an access point in an Ethernet network.

While browsing gopackets.com a while back, I came across a NETVANTA 1234 POE Ethernet switch that supported 802.3af that cost $824.90. A similar switch, the NETVANTA 1234, cost only $359.85. Based on the specifications, the only difference is that the cheaper switch does not support 802.3af. Which of the following justifies the extra cost of an 802.3af switch?

An 802.3af switch can provide power, which means that you can power things like WiFi access points without having to have an electrician pull electric cable.

A new standard called 802.11ad "WiGig" has been proposed that is already seeing a major push from hardware manufacturers. Which of the following is false about who is in charge of this standard?

Bob Metcalfe has significant involvement in the development of this standard.

You just got a job at a small company that has expanded rapidly from six employees to 30. In the server room, they have two 100Base-TX switches, one with 16 ports, and one with 24 ports that are uplinked using the standard uplink port. All of the patch cables in the rack are the same lovely blue color. Which of the following is the lowest cost thing that would add a professional touch to this company's equipment rack?

Buying a bright red or orange crossover cable to uplink the two switches.

In order for 802.11n to reach top speed, it must use channels in the 5 GHz frequency band. Which of the following correctly describes the trade off between the 2.4 GHz and 5 GHz frequency bands?

Channels in the 2.4 GHz range are more than twice as likely to encounter interference than channels in the 5 GHz range.

When I was teaching at the University of Tulsa, they used VLANs to separate the student and faculty networks in the business building even though they only had one telecommunications closet. Which of the following was false about TU's Ethernet network?

Every NIC on every computer had to be configured to say which VLAN it belonged to.

On wired Ethernet links, a device can begin transmitting right away, while wireless links require a waiting period. Which of the following is the reason why this delay is added on wireless links?

If a wireless device is transmitting, it is hard for it to detect that another device is transmitting at the same time over the same channel.

Which of the following is not a reason why overprovisioning is used instead of priority?

Overprovisioning is a better way to ensure that no capacity is wasted.

Your networking professor has recommended that you only buy rack-mountable equipment. However, your boss has found a source for 1200 VAC uninterruptible power supplies that is about half the cost of the rack-mountable UPS that you wanted to buy. Which of the following is the best thing you should do to convince your boss that rack-mountable is a better option?

Show your boss your equipment rack and explain that the UPS would have to sit on top of other equipment or you will have to buy a shelf for it.

Which of the following is the only feature you can expect from a consumer switch (the others are only available on a managed switch)?

Switches between 10Base-T, 100Base-TX, and 1000Base-T automatically.

Which of the following is true about Ethernet switching?

Switches start from nothing, and learn based on source MAC addresses of frames that are sent.

Your company uses a video chat application running over its Ethernet network instead of phone calls. On some of the calls, the audio sounds "jittery" and the video kind of stops and starts. Which of the following would not be something that causes "jitter"?

The access lines running from the workstations to the workgroup switches are too slow to accommodate the video.

Which of the following would be the most important consideration when purchasing Ethernet switches for a newly started company that currently employs 8 people?

The company is likely to expand quickly, so they should purchase stackable switches.

Your company occupies every floor of a four story building. At your company, there are large chassis switches on every floor that connect all of the workstations on that floor using 100Base-TX. Those switches are all connected to a switch in the basement equipment room via mulitmode fiber. Which of the following is true about the best design for this network?

The company's servers will be connected to the switch in the basement, so it will need to be very fast.

Which of the following will require you to pull new fiber optic cable when upgrading to a faster trunk line speed?

The current run length might be too far at the new speed.

At Sam Houston Race Park, the grandstand is about 50 meters north of the administration building, and the north pavilion is about 50 meters north of the grandstand. The grandstand itself is about 150 meters across, so the overall distance from the administration building to the north pavilion is about 250 meters. Which of the following is true about using Ethernet networking at this firm?

The distance from the administration building to the north pavilion can be spanned using multimode fiber.

ODU uses thin wireless access points for its wireless network. What is the difference between these access points and the access points that consumers have?

They rely on another device called a WLAN switch for most of their functioning.

PRA occupies four buildings in an office park near Military Circle that are connected using Ethernet. The center building houses the data center, and for a long time they have had three fiber cables that run between each of the other buildings and the data center building. They worry about cable breaks, so they will run cables between the other three buildings so they can have some redundancy. In order to ensure that the data center remains the core of their network, which of the following will they need to do when they connect these new links?

They will have to configure their managed switches so that the data center switch is at the top of the hierarchy.

In my basement, I have a 100Base-TX Ethernet hub. What is different about the Ethernet traffic in my house versus the traffic in Constant Hall?

When I copy files from one computer to another in my house, it takes longer than if I had a switch.

Which of the following is not a concern when upgrading from a lower speed of Ethernet to a higher speed?

Your older Ethernet equipment will not be supported, so you will have to buy new NICs for your computers.