So many ways... Here's a few.
- use a network packet watcher or sniffer to monitor packets into and out of your network connections; packet sniffers tend to be OS specific. You may want different sniffers on each of the client and server
- use
telnet -p {port_number}
to test connections on a port number; commonly installed on Linux systems, no idea about Windows.
- use
netcat
to connect to ports
- use
curl
and enable the debugging options -trace
Personally, faced with your situation, I'd be looking for telnet
and specifying the port number, as a first step. If that doesn't connect, I'd try changing the server port number to 80, and see if that works. If 80 works and 3000 fails... then something is blocking it. It's fairly easy to set the rails server port in development mode, but if you can't find those docs... add a comment. ;)
ping
is a less useful tool than you might expect. It uses the ICMP protocol, rather than TCP or UDP. As a consequence, things may be reachable by ICMP that aren't reachable by TCP or UDP. And vice-versa - ICMP flooding attacks have been very popular, so some hosts disable ICMP in firewalls - even though you can connect to port 80 or 443 in the usual ways. On a local network with no external firewalls tinkering, it's a fairly good test of connection.
Line is not going to answer any question. its an online service to test ports – Bender – 2014-08-11T08:58:27.897