I have burned a lot of time thinking a host was down only to find it blocks ICMP echo (ping).
As a follow-up to a ping fail, I check to see if a known port is open using nmap.
gist: https://gist.github.com/veganjay/6b902c478bda429187f39e53a5b...
As a follow-up to a ping fail, I check to see if a known port is open using nmap.
gist: https://gist.github.com/veganjay/6b902c478bda429187f39e53a5b...
nc -zv 1.1.1.1 443
cat > /dev/tcp/www.google.com/443> cat > /dev/tcp/www.google.com/443
I was unfamiliar with this device so I googled a bit. This isn't a real file/device, it's a bash-ism when built with --enable-net-redirections (apparently disabled in debian-based distros [1]).
That's too bad, would have been cool to have such easy access to sockets anywhere using fopen().
1. https://www.oreilly.com/library/view/bash-cookbook/059652678...