There are several tools that you can use to monitor HTTP packets, also known as packet sniffing, on a Linux system. Some popular options include:
Wireshark: Wireshark is a widely used packet sniffing and analysis tool that is available for Linux systems. It can capture and display packets in real-time, and provides a range of features for analyzing and filtering packets.
Tcpdump: Tcpdump is a command-line packet sniffing tool that is available on most Linux systems. It can capture packets and display them in a human-readable format, and can be used with a range of options and filters to capture specific packets.
Netcat: Netcat is a network utility that can be used to capture and display packets on a Linux system. It can listen for packets on a specific port, or connect to a server to receive packets.
Tshark: Tshark is the command-line version of Wireshark that can be used to capture and display packets on a Linux system. It has many of the same features as Wireshark, and can be used with a range of options and filters.
ngrep: Ngrep is a packet sniffing tool that can capture and display packets based on their content. It can be used to search for specific patterns in packet payloads, and can be used with a range of options and filters.
To use these tools to monitor HTTP packets, you can specify the tcp port 80 filter to capture only packets that use the HTTP protocol. You can also use other filters and options to capture specific packets or analyze the packet data in more detail.