Networking case-projects 2

Case Project 2-1

You have been hired to upgrade a network of 50 computers currently connected to 10 Mbps hubs. This long-overdue upgrade is necessary because of poor network response time caused by a lot of collisions occurring during long file transfers between clients and servers. How do you recommend upgrading this network? What interconnecting devices will you use, and what benefit will you get from using these devices? Write a short memo describing the upgrade and, if possible, include a drawing of the new network.

I would get two of these ubiquiti 48 port switches for gigabit ethernet. Communicating to local servers and other computers allows for up to 1000Mbps bandwidth.

I’d get a few of these for the wireless connection for employees.

I’d get a unifi cloud key to manage the wireless and switches

For the firewall I’d get a fortigate 80e because they are really great on the graphical interface side of things. You can see what ip addresses are using what bandwidth and applications. The command line is also very nice. Antivirus can be handled by the firewall to scan incoming/outgoing traffic before it even reaches computers. Their support is also very good. If ever I would have any questions I could call them and they could tell me exactly where my problem is on the config.

I guess you could say drawback might be cost but the increased productivity, good warranty, and good support from ubiquiti and fortigate make it more than worth it. They would need to upgrade their voip phones to something that would support gigabit connections (as the phones typically connect to the switch and the computer connects to the phone). Any voip phones in the last few years would do.

Setting it up would probably take a few days to get all the firewall rules, traffic shaping, firmware upgrades, registered wireless devices, and actually doing the physical installation, and then documenting it all and mapping the network out. Then also monitoring from something like nagios/cacti or solarwinds would need to be set up. Something really granular like smokeping could be set up to ping everyone’s phone continuously as well as the internet connection to check for momentary drops in network connectivity to verify network issues for voip calls. Traffic shaping would have to be set up to make sure there is always available bandwidth for phones no matter how much network bandwidth is used. Port forwarding would have to be set up if people want access to internal servers from the outside. Dns would have to be set up on the fortigate to a local dns server (assuming one exists for internal domains).

Also appropriate ethernet cable (like Cat6 or higher) would need to be installed to support the upgraded bandwidth capability of the switches and fortigate.

Case Project 2-2

Two hundred workstations and four servers on a single LAN are connected by a number of switches. You’re seeing an excessive number of broadcast packets throughout the LAN and want to decrease the effect this broadcast traffic has on your network. What steps must you take to achieve this goal?

I could enable broadcast storm protection on the switches, or I could use wireshark to identify the source of the broadcast packets in case it’s one or a few sources that are sending those packets unnecessarily.

Case Project 2-3

In Chapter 3, you learn about network topologies and technologies. As prepa-

ration, do Internet research on the following topics:

Physical versus logical topology

  • Physical is how devices are actually connect with wires and networking equipment. Logical is how things appear to be connected to the network user.

Bus topology

  • The computer or network device are connected via a single cable.

Star topology

  • Most commonly used, every node connects to a central network device like a hub/switch/computer. Typically rj45 cables connect the computers to the central device.

Ring topology

  • Device connections form a circular path (doesn’t necessarily have to look like a circle) where each computer is connected to its two neighbors. Data goes from computer to computer until it reaches its destination. Can be bad if one computer goes down and the link is broken, especially if it’s unidirectional (data can only go one way around the ring).

Ethernet and CSMA/CD

  • CSMA/CD is Carrier Sense Multiple Access Collision is what ethernet uses to handle half-duplex mode of transmission. Computers listen for ongoing traffic before they can transmit. They cannot transmit and receive at the same time. This is designed to reduce data collision. Each computer intermittently tries to send data after the user tells the computer to do so (or software indicates it is time to do so) and when there is no traffic it will complete the sending of a frame. This only will be used in a logical bus technology (connected to a hub or sharing an ethernet connection with another computer). If both computers are individually connected to a switch, they would instead connect at full-duplex as the switch would handle transmission from multiple sources of data at the same time.