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Showing posts from March, 2026

Networks Lab PCCSL507 Semester 5 KTU CS 2024 Scheme - Dr Binu V P

 About Me   Dr Binu V P Syllabus Learn Linux well before you start- refer blog Experiments Familiarize Linux networking commands ifconfig ifplugstatus iftop ping ip traceroute mtr netstat whois nmap nmcli speedtest-cli bmon nslookup tcpdump Wireshark     Download Wireshark     Wireshark Documentaion     Setting up a capture     Capturing Live network data      Analysis of HTTP Protocol using Wireshark Socket Programming Basic Implementation of  TCP Client Server Communication using sockets. TCP Client-Server Communication to Identify Matrix Type (Upper/Lower/Diagonal) Implementation of UDP Client-Server Communication using Sockets in C UDP Client-Server Communication for Translating “New Generation English” to Formal English Cisco's Packet Tracer

Study of tcpdump Command

  Experiment Study of tcpdump Command ๐ŸŽฏ Aim To capture and analyze network packets using the tcpdump command. ๐Ÿ“˜ Objective By the end of this experiment, students will be able to: Capture live network traffic Filter packets based on protocol, port, or host Analyze packet-level communication Understand basic packet structure ๐Ÿ“– Theory The tcpdump command is a packet analyzer (sniffer) used to: Capture network packets in real time Display detailed information about each packet ๐Ÿ‘‰ It works at a low level and can capture: TCP, UDP, ICMP traffic Packets to/from specific hosts or ports ๐Ÿ‘‰ Commonly used for: Network troubleshooting Security analysis Debugging network applications ๐Ÿงพ Syntax sudo tcpdump [options] [filter] ๐Ÿ”ง Common Options -i <interface> → Specify interface (e.g., eth0 ) -n → Do not resolve hostnames -c <count> → Capture limited number of packets -w <file> → Save packets to file -r <file...

Study of nslookup Command

  Experiment Study of nslookup Command ๐ŸŽฏ Aim To query DNS servers and obtain domain name or IP address mapping using the nslookup command. ๐Ÿ“˜ Objective By the end of this experiment, students will be able to: Resolve domain names to IP addresses Perform reverse DNS lookups Query specific DNS servers Understand DNS record types ๐Ÿ“– Theory The nslookup ( name server lookup ) command is used to: Query the Domain Name System (DNS) Translate: Domain name → IP address IP address → Domain name ๐Ÿ‘‰ It helps in: Troubleshooting DNS issues Verifying DNS configuration Checking domain resolution ๐Ÿ‘‰ It works in: Non-interactive mode (single query) Interactive mode (multiple queries) ๐Ÿงพ Syntax nslookup [options] <domain_or_ip> [dns_server] ๐Ÿ”ง Common Usage Non-Interactive Mode: nslookup google.com Reverse Lookup: nslookup 8.8.8.8 ๐Ÿงฐ Prerequisites Linux system Internet connectivity DNS configured ๐Ÿ”ฌ Procedure & Comma...

Study of bmon Command

  Experiment  Study of bmon Command ๐ŸŽฏ Aim To monitor network bandwidth usage in real-time using the bmon command. ๐Ÿ“˜ Objective By the end of this experiment, students will be able to: Monitor real-time bandwidth usage of network interfaces Analyze incoming and outgoing traffic Compare bandwidth across multiple interfaces Understand graphical/text-based traffic representation ๐Ÿ“– Theory The bmon ( Bandwidth Monitor ) command is a tool used to: Display real-time network bandwidth usage Provide both text and graphical interface in terminal ๐Ÿ‘‰ It shows: Data transfer rates (incoming & outgoing) Interface-wise bandwidth usage Traffic statistics in a visual format ๐Ÿ‘‰ Compared to tools like iftop , bmon focuses more on: Interface-level monitoring rather than per-connection ๐Ÿงพ Syntax bmon [options] ๐Ÿ”ง Common Options -p <interface> → Monitor specific interface -o <output> → Output format (e.g., ascii) -r <rat...

Study of speedtest-cli Command

  Experiment:  Study of speedtest-cli Command ๐ŸŽฏ Aim To measure internet bandwidth (download and upload speed) using the speedtest-cli command. ๐Ÿ“˜ Objective By the end of this experiment, students will be able to: Test internet speed from the command line Measure download and upload bandwidth Analyze network performance Compare speeds under different conditions ๐Ÿ“– Theory The speedtest-cli is a command-line tool used to: Test internet speed using Speedtest.net servers Measure: Ping (latency) Download speed Upload speed ๐Ÿ‘‰ It connects to the nearest or selected server and performs data transfer tests. ๐Ÿ‘‰ Useful for: Network troubleshooting ISP performance analysis Lab performance evaluation ๐Ÿงพ Syntax speedtest-cli [options] ๐Ÿ”ง Common Options --simple → Simple output (minimal details) --list → List available test servers --server <id> → Select specific server --bytes → Show speeds in bytes instead of bits ...

Study of nmcli Command

  Experiment Study of nmcli Command ๐ŸŽฏ Aim To configure and manage network connections using the nmcli command in Linux. ๐Ÿ“˜ Objective By the end of this experiment, students will be able to: View network devices and connections Connect to wired and wireless networks Configure IP settings Manage network profiles using CLI ๐Ÿ“– Theory The nmcli ( Network Manager Command Line Interface ) is used to: Control the NetworkManager service from the terminal Manage network connections (wired, Wi-Fi, VPN) Configure IP addresses, DNS, and gateways ๐Ÿ‘‰ It is a modern and powerful alternative to manual configuration using ifconfig or ip . ๐Ÿ‘‰ It works with: Devices (hardware interfaces) Connections (saved network profiles) ๐Ÿงพ Syntax nmcli [OPTIONS] OBJECT COMMAND Common OBJECTS: device → Network interfaces connection → Network profiles general → NetworkManager status ๐Ÿงฐ Prerequisites Linux system with NetworkManager Root/sudo privileges f...

Study of nmap Command

  Experiment Study of nmap Command ๐ŸŽฏ Aim To explore and analyze network hosts and services using the nmap command. ๐Ÿ“˜ Objective By the end of this experiment, students will be able to: Discover active hosts in a network Scan open ports Identify running services Understand basic network security scanning ๐Ÿ“– Theory The nmap ( Network Mapper ) command is a powerful tool used for: Network discovery Security auditing Port scanning ๐Ÿ‘‰ It works by sending packets to target systems and analyzing responses. ๐Ÿ‘‰ It can detect: Open ports Closed ports Filtered ports (blocked by firewall) ๐Ÿงพ Syntax nmap [options] <target> <target> → IP address, hostname, or network range ๐Ÿ”ง Common Options -sS → TCP SYN scan (stealth scan) -sT → TCP connect scan -sU → UDP scan -p → Specify port(s) -A → Aggressive scan (OS + version detection) -O → OS detection -v → Verbose output -F → Fast scan (common ports only) ๐Ÿงฐ Prereq...