How can I test an outbound connection to an IP address as well as a specific port?

Question

OK, we all know how to use PING to test connectivity to an IP address. What I need to do is something similar but test if my outbound request to a given IP Address as well a

Answer 1

The fastest / most efficient way I found to to this is with nmap and portquiz.net described here: http://thomasmullaly.com/2013/04/13/outgoing-port-tester/ This scans to top 1000 most used ports:

# nmap -Pn --top-ports 1000 portquiz.net

Starting Nmap 6.40 ( http://nmap.org ) at 2017-08-02 22:28 CDT
Nmap scan report for portquiz.net (178.33.250.62)
Host is up (0.072s latency).
rDNS record for 178.33.250.62: electron.positon.org
Not shown: 996 closed ports
PORT     STATE SERVICE
53/tcp   open  domain
80/tcp   open  http
443/tcp  open  https
8080/tcp open  http-proxy

Nmap done: 1 IP address (1 host up) scanned in 4.78 seconds

To scan them all (took 6 sec instead of 5):

# nmap -Pn -p1-65535 portquiz.net