ping

well, it’s not actually about ping right now but what to do when ping is not available

if there’s no ping, nc, telnet available

like in a container, do this (but you need bash, heh):

(echo >/dev/tcp/${host}/${port}) &>/dev/null && echo "open" || echo "closed"

example:

(echo >/dev/tcp/8.8.8.8/53) &>/dev/null && echo "open" || echo "closed"

source