Networking & Diagnostics
Complete guide to network troubleshooting, diagnostic tools, connectivity issues, and performance optimization for IT professionals and administrators.
Articles in Networking & Diagnostics
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How to query DNS → dig
ANY +short or host Learn how to query DNS records using dig and host commands. Complete guide with examples, troubleshooting, and best practices for DNS lookups and analysis.
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How to decode with tshark → tshark -i
-f Master tshark network packet capture and decoding with comprehensive guide covering interface selection, filtering, real-world examples, and troubleshooting tips.
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How to capture packets → tcpdump -i
Master network packet capture with tcpdump. Complete guide covering interface selection, filtering, practical examples, troubleshooting, and best practices for beginners to experts.
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How to relay/pipe sockets → socat
Learn how to use socat for socket relaying and piping with comprehensive examples, troubleshooting, and best practices for network connectivity solutions.
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How to probe TCP/UDP quickly → nc -vz
Master network connectivity testing with netcat's nc -vz command. Learn TCP/UDP port probing, troubleshooting techniques, and practical examples for quick diagnostics.
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How to scan ports/services → nmap -sV
Learn how to scan ports and services using nmap -sV command. Complete guide with examples, troubleshooting, and best practices for network reconnaissance.
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How to test bandwidth → iperf3 -s / iperf3 -c
Learn how to test network bandwidth using iperf3 commands. Complete guide covering server setup, client connections, advanced options, and troubleshooting tips.
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How to check interfaces’ speed/duplex → ethtool
Learn how to check network interface speed and duplex settings using ethtool command. Complete guide with examples, troubleshooting, and best practices for Linux admins.
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How to check sockets (modern) → ss -tulpen
Learn how to check network sockets using the modern ss command with -tulpen options. Complete guide with examples, troubleshooting, and best practices for Linux.
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How to trace network path → traceroute
or mtr Learn how to trace network paths using traceroute and mtr commands. Complete guide with examples, troubleshooting, and best practices for network diagnostics.
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How to test reachability → ping
Learn how to test network reachability using the ping command. Complete guide with examples, troubleshooting tips, and best practices for network connectivity testing.
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How to manage NetworkManager → nmcli device|connection ..
Master NetworkManager's nmcli command-line tool for managing network devices and connections. Complete guide with examples, troubleshooting, and best practices.
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How to check ARP/neighbor cache → ip neigh
Learn how to check ARP/neighbor cache using ip neigh command. Complete guide with examples, troubleshooting, and best practices for network administrators.
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How to add route/addr → ip route add ...; ip addr add ..
Learn to configure network routes and addresses using ip route add and ip addr add commands. Complete guide with examples, troubleshooting, and best practices.
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How to show IP/links/routes → ip addr|link|route
Learn how to use Linux ip commands to display network interfaces, IP addresses, links, and routing tables. Complete guide with examples and troubleshooting.