Firewalls are designed to keep your privacy and your PC safe. A Firewall can either be hardware or software. Hardware firewalls are generally used to protect large networks of computers whereas software firewalls are generally used to protect one computer at a time. Firewalls can greatly increase your protection from identity and credit card theft.
Often a network application is not working properly, because the port is being blocked either by a proxy, router, or firewall.
| Service / Application | Port | Type |
|---|---|---|
| FTP | 21 | TCP / UDP |
| TELNET | 23 | TCP / UDP |
| SMTP (Email) | 25 | TCP / UDP |
| Remote Access Protocol | 38 | TCP / UDP |
| Web Browsers (Http) | 80 | TCP / UDP |
| mIRC Chat (incoming) | 101 | TCP |
| Post Office Protocol - Version 3 (Pop3) | 110 | TCP / UDP |
| Sql Services (Sqlserv) | 118 | TCP / UDP |
| mIRC Send (trigger) | 120 | TCP |
| Sql Service (Sqlsrv) | 156 | TCP / UDP |
| MSN NetMeeting | 389 | TCP |
| Remote Assistant (Ra) | 1053 | TCP / UDP |
| Microsoft-Sql-Server (Ms-Sql-S) | 1433 | TCP / UDP |
| Microsoft-Sql-Monitor (Ms-Sql-M) | 1434 | TCP / UDP |
| AlternateWeb Browsers (Http) | 8080 | TCP / UDP |
You can test the effectiveness of your firewall by opening the windows DOS prompt. Use netstat to view all ports located on your system. Look for any port that has the state of ESTABLISHED.
Netstat
Displays protocol statistics and current TCP/IP network connections.
NETSTAT -A -A Displays all connections and listening ports.
Tracert
Trace an IP address TRACERT ###.###.###.###
