Perform a scan on a remote host to detect if any packet filters or Firewall is used by host.

sudo nmap -sA sharewiz.net

Result:

Starting Nmap 6.40 ( http://nmap.org ) at 2016-07-08 00:28 BST
Nmap scan report for 192.168.1.2
Host is up (0.0011s latency).
All 1000 scanned ports on 192.168.1.2 are unfiltered
MAC Address: 44:A8:42:34:16:49 (Unknown)

Nmap done: 1 IP address (1 host up) scanned in 90.32 seconds

Another machine:

Result:

Starting Nmap 6.40 ( http://nmap.org ) at 2016-07-08 00:31 BST
Nmap scan report for sharewiz.net (5.42.134.35)
Host is up (0.045s latency).
rDNS record for 5.42.134.35: bbdp5.42.134.35.network.sure.com
All 1000 scanned ports on sharewiz.net (5.42.134.35) are unfiltered (919) or filtered (81)

Nmap done: 1 IP address (1 host up) scanned in 2.51 seconds