I have Solaris 10 SPARC running on my customer side. I have root account so that I can install any software. Last time I install monit which making port 2812 Listen and I can access locally. On my side I use VPN connection to customer server. When I try to check port 2812 is inaccessible even port in Listening. I realized that port may be blocked by some firewall. My object is to find some port that accessible. The question is how to check which port is allowed by firewall to access?