Computer Networks

In its broadest sense, a ​network consists of two or more devices, sharing resources and information via a medium. The desktops on the school are all connected via the school network. Your mobile phone is part of your service providers mobile network. The devices can be interconnected using physical cables or wireless.

The ​Internet is the global system of interconnected computer networks that uses the ​Internet protocol suite (TCP/IP) to communicate between networks and devices

How are messages delivered over the network.

What happens when you mail a letter to a friend

1. Write a letter on a piece of paper
2. Put the letter in an envelope
3. Write your friends address on the envelope
4. Write your address on the envelop (in case your friend wants to send a reply)
5. We carry the letter to the mailbox and mail it.
6. Mail man picks up the letter and takes to the post office
7. Post Office sorts all incoming Letters and send yours to your friends home
8. Mail man delivers the mail to your friends home.
9. Your friend receives your letter, opens the envelope and reads your message.

What happens when Control Station send messages to the Robot.

1. Driver engages the joystick button. Software running on the (Driver Station) Laptop detects it. Software issues a command to Robot
2. FRC library encapsulates the command in an IP

Troubleshooting Network Issues

Useful tools

• ​ping: Used to test the reachability of a host on a network
  • Usage "ping IP_Address"
• ​ifconfig(linux) / ​ipconfig(windows): display network interface configuration
  • Usage "ifconfig"
• ​traceroute(linux)/tracert(Windows): Diagnostic command for displaying possible routes (paths) for packets across the network
  • Usage "traceroute IP_Address"
• route: Command to display the routing configuration on a host / router
  • Usage "route -v"
• ​arp: List the ARP table entries on the host/router
  • Usage "arp -a"