A systems administrator is investigating why users cannot reach a Linux web server with a browser but can ping the server IP. The server is online, the web server process is running, and the link to the switch is up. Which of the following commands should the administrator run on the server first?
To diagnose why users cannot reach a Linux web server with a browser, the administrator should first run the 'netstat' command. This command is useful for checking if the server is listening on the expected ports (such as 80 for HTTP and 443 for HTTPS). Netstat provides information about active connections, listening ports, and the services using those ports. If the web server is not listening on the correct ports, users would not be able to access it via a browser despite being able to ping the server IP.
With netstat he can check if port 80 and 443 are running
B. netstat The command netstat -tulpn | grep 80 -t: Shows TCP connections. -u: Shows UDP connections. -l: Shows only listening sockets. -p: Shows the process ID and name of the process using the socket. -n: Shows numerical addresses instead of resolving hostnames. grep 80 filters the output to show only lines containing port 80 and which process is associated with it.
C. tcpdump When investigating why users cannot reach a Linux web server with a browser but can ping the server IP, the administrator should run the tcpdump command on the server first. Tcpdump is a packet analyzer that allows the administrator to capture and analyze network traffic in real-time. By running tcpdump, the administrator can inspect the packets arriving at the server, which can provide insights into whether the server is receiving HTTP traffic and whether there are any issues with the communication. Options A (traceroute), B (netstat), and D (arp) are useful for different purposes but may not directly help diagnose the issue at hand. Traceroute shows the path taken by packets, netstat displays network statistics and connections, and arp resolves IP addresses to MAC addresses. Tcpdump is better suited for capturing and analyzing the actual traffic arriving at the server, helping identify potential issues with web traffic.
C tcpdump tcpdump is a packet analyzer tool used to capture and display TCP/IP and other packets being transmitted or received over a network. By running tcpdump on the Linux web server, the administrator can examine the incoming network traffic and check if requests to the web server are reaching the server and if the server is responding to those requests. This can help identify any potential issues with the network traffic flow or the web server configuration.