Package: netcat-openbsd
Connect to a server on a given IP and port (telnet
on steroids)
nc 10.10.2.1 80
Check connectivity towards a server on a given IP and port
nc -vz -w 4 10.10.2.1 80
v: verbose z: just check if the connection can be opened w: 4 seconds timeout
Start a simple TCP listener on a port
nc -l -p 4080
Package: nmap
Discover all hosts on a network with ping
nmap -sP 10.10.2.0/24
Discover open ports on a given host
nmap -sS 10.10.2.30
Package: openssl
Connect to an TLS server and check certificate
openssl s_client -showcerts -verify 5 -connect 10.10.2.33:443 < /dev/null
Package: curl
Connect to a Webserver and check the status code, headers and content returned
curl -s -D - https://google.com
Add -k
to skip certificate verification.