Packet Analysis: DNS, FTP

Welcome to our Packet Analysis Lab focused on DNS (Domain Name System) and FTP (File Transfer Protocol). In this hands-on session, we delve into the intricate world of packet analysis using Wireshark, exploring the functionality of DNS and uncovering the potential security risks associated with FTP.

DNS

The Domain Name System (DNS) serves as the backbone of the internet, providing a critical translation service that converts human-readable domain names into machine-readable IP addresses. In our Packet Analysis Lab, we delve into the inner workings of DNS to understand its pivotal role in facilitating seamless communication over the internet.

Key Components of DNS:

1. Domain Names: Human-friendly, alphanumeric names used to identify websites and resources on the internet (e.g., www.example.com).

2. IP Addresses: Numeric addresses assigned to devices connected to a network, enabling data routing and communication.

3. DNS Servers: Distributed across the internet, these servers store DNS records, mapping domain names to corresponding IP addresses.

DNS Resolution Process:

1. User Query: When a user enters a domain name in a web browser, a DNS query is initiated to resolve the corresponding IP address.

2. Local DNS Cache: The user's device checks its local DNS cache to see if the mapping is already stored, reducing the need for repeated queries.

3. Recursive DNS Server: If the information is not in the local cache, the device contacts a recursive DNS server, which may have the required mapping or initiates further queries.

4. Authoritative DNS Server: The recursive server communicates with authoritative DNS servers, which hold the official records for specific domain names.

5. Response: The authoritative server provides the IP address to the recursive server, which, in turn, passes it to the user's device, completing the resolution process.

During the lab session, we will capture and analyze DNS packets using Wireshark, gaining insights into the structure of DNS queries and responses. 

FTP

File Transfer Protocol (FTP) is a standard for transferring files between computers on a network. In our lab, we analyze FTP packets using Wireshark to understand its structure and potential security risks.

Key Aspects

1. Client-Server Model: FTP operates on a client-server architecture.

2. Active and Passive Modes: Two modes for data transfer.

3. Commands: FTP uses commands like RETR and STOR for file transfer.

4. User Authentication: Requires credentials (username, password) for access.

Lab Focus

1. User Credentials: Analyze how FTP transmits user IDs and passwords.

2. File Download: Identify and export files downloaded using FTP.

3. Security: Discuss security risks and consider secure alternatives like SFTP or FTPS.

Conclusion 

This lab provides a comprehensive exploration of DNS and FTP packet analysis, bridging theoretical knowledge with practical skills. Participants will leave with a heightened understanding of these protocols, along with the ability to inspect DNS traffic, identify potential security risks in FTP communication, and apply best practices for secure network data transfer. Join us in uncovering the secrets hidden within network packets!