Network Command

\#linux

Basic Command

Command	Description
`ifconfig`	check ip address of local
`netstat`
`ping`	check ping
`dig`
`nslookup`
`traceroute`

elinks - lynx-like alternative character mode WWW browser
- e.g. elinks <url>
curl - transfer a URL
- e.g. curl <url>
wget - The non-interactive network downloader
- e.g. wget <url>
nc - arbitrary TCP and UDP connections and listens

nc - arbitrary TCP and UDP connections and listens
netcat nc ncat

connect to chal.firebird.sh TCP port 35009

nc -v chal.firebird.sh 35009

create a TCP server on port 9001, and connect the program's stdio to the connection

ncat -klve ./executable_file -p 9001
ncat -klvc 'python -u file.py' -p 9001 

HTTP: Looking into curl

curl -v chal.firebird.sh:35001

Demo: Lets' browse the web by hand!

https://developer.mozilla.org/en-US/docs/Web/HTTP/Messages

nc -v google.com 80
GET /not_exists HTTP/1.1
Host: google.com
(enter twice)
-> same as http://google.com/not_exists
telnet chal.firebird.sh 35001
GET / HTTP/1.1
Host: chal.firebird.sh

# This is a valid HTTP response
echo "HTTP/1.1 200 OK\n\n<h1>It works!"
# We use netcat to bind our command to the TCP port 31330
# Whenever someone connect to the port, netcat will invoke the command and
send our response to the client.
ncat -klvc 'echo "HTTP/1.1 200 OK\n\n<h1>It works!"' -p 31330
# Open your browser and navigate to: http://localhost:31330/

Last modified: 12 June 2025