CSP26W1: Wireshark: This lab uses the Wireshark software tool to capture and examine a packet trace: Lab 1 Wireshark Protocol Assignment, Singapore

Objective

To learn how protocols and layering are represented in packets. They are key concepts for structuring networks that are covered in §1.3 and §1.4 of your text. Review those sections before doing the lab.

Requirements

Wireshark: This lab uses the Wireshark software tool to capture and examine a packet trace. A packet trace is a record of traffic at a location on the network, as if a snapshot was taken of all the bits that passed across a particular wire. The packet trace records a timestamp for each packet, along with the bits that make up the packet, from the lower-layer headers to the higher-layer contents. Wireshark runs on most operating systems, including Windows, Mac and Linux.

It provides a graphical UI that shows the sequence of packets and the meaning of the bits when interpreted as protocol headers and data. It color-codes packets by their type, and has various ways to filter and analyze packets to let you investigate the behavior of network protocols. Wireshark is widely used to troubleshoot networks. You can download it from www.wireshark.org if it is not already installed on your computer. We highly recommend that you watch the short, 5 minute video “Introduction to Wireshark” that is on the site.

wget / curl: This lab uses wget (Linux and Windows) and curl (Mac) to fetch web resources.

wget and curl are command-line programs that let you fetch a URL. Unlike a web browser, which fetches and executes entire pages, wget and curl give you control over exactly which URLs you fetch and when you fetch them. Under Linux, wget can be installed via your package manager.

Under Windows, wget is available as a binary; look for download information on http://www.gnu.org/software/wget/. Under Mac, curl comes installed with the OS. Both have many options (try “wget –help” or “curl –help” to see) but a URL can be fetched simply with “wget URL” or “curl URL ”.