Background : It's a common question as we can search at google "ping works but http does not"
ping is not a reliable test of network connectivity.
ping working just means enough of the IP stack is up to process ICMP Echo requests (that's not a huge portion of the system compared to what's required for SSH and web servers). We could have had what I call a "partial panic" (Kernel blew up, but the IP code kept running), run out of RAM, or our SSH/HTTPd processes could have fallen over for unspecified reasons.
- Server not responding to SSH and HTTP but ping works
My Question : Any command line tool for ping HTTP?