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In today's world, where information technology is pivotal to the operation of nearly every organization, the ability to quickly and effectively troubleshoot computing issues is essential. Problems at the system and network level can range from performance issues to security incidents. To identify and resolve these issues, we can use a variety of tools, including strace, tcpdump, and others. These tools provide valuable insights into what is happening "under the hood" of our systems and networks.

Using strace

strace is a tool in Unix and Linux environments that monitors the system calls and signals of processes. It allows us to "peek inside" a running process and find out what operations it is performing at the kernel level.

• Basic usage: To start monitoring a process, you can use the command strace <command>. This command will launch a new process and display all the system calls made by the process.

• Advanced usage: To attach to an already running process, use strace -p <PID>, where <PID> is the process ID. Various switches, such as -e to specify particular calls, can be used to filter the output.

Using tcpdump

tcpdump is a tool for capturing and analyzing network traffic. It allows monitoring packets that pass through network interfaces, providing detailed information about protocols and communication between devices.

• Basic usage: Running tcpdump -i <interface> will capture and display packets passing through the specified interface. <interface> could be, for example, eth0 for the first Ethernet interface.

• Advanced usage: The command tcpdump -i <interface> -n port <port> filters communication by a specific port. The -w switch allows saving packets to a file for later analysis.

Other Tools

Besides strace and tcpdump, there are many other tools that can aid in diagnosing and solving problems.

• Wireshark: A graphical tool for network traffic analysis that provides an interface for easier interpretation of data captured by tcpdump.

• netstat: A tool for displaying active network connections, listening ports, and other network statistics.

• htop: An interactive process monitor that displays running processes and allows for their management.

For effective problem resolution at the system and network level, it's important to master a wide range of tools and understand the principles of their operation. strace, tcpdump, and other tools are key for diagnostics and analysis, enabling system administrators and network engineers to quickly identify and address issues, thereby increasing the reliability and security of information systems.