In this level, you will learn how to create packets and send them from one computer to another.

Pause the simulation and click on the packet that is sent from Bob's computer to Alice's computer. The information about a packet is contained in its packet headers. This is a simple packet that only lists information in the network layer. Note the two pieces of information contained in this header: srcip (the source of the packet) and dstip (the destination of the packet).

To pass this level, you will need to send a packet from Alice to Bob. To do this:

• open the Timeline Editor
• open Basics → Level 2 by going to File → Change level
• add a new packet by selecting the Add Packet option from the File menu (or by pressing Ctrl+N)
• we need to send this packet from Alice, so make sure she is selected in the From: dropdown
• you need to set the srcip and dstip headers in the network layer
  hint: restart and pause the simulator to click on packets and see what their headers look like
• save your new packet by selecting the Save option from the dropdown menu (or by pressing Ctrl+S)

Now that you have saved a packet to the timeline, go back to the Simulator and press reload. When the timer in the corner hits the "At:" value of your packet, it will be sent!

Level Objectives

• Send a packet from Alice to Bob