Hello folks,
In this post I mentioned the necessary services and their port should be opened by default in firewall on the server. Here I am considering that you are using
CSF (Config Server Firewall) as a firewall to secure your server.
Beneath is the list of services and their port numbers, open these ports in firewall.
QuoteTCP_IN = "20,21,22,25,53,80,110,143,443,465,587,993,995"
TCP_OUT = "20,21,22,25,53,80,110,113,443"
UDP_IN = "20,21,53"
UDP_OUT = "20,21,53,113,123"
Services using these open ports are:
Port 20: FTP data transfer
Port 21: FTP control
Port 22: Secure shell (SSH)
Port 25: Simple mail transfer protocol (SMTP)
Port 53: Domain name system (DNS)
Port 80: Hypertext transfer protocol (HTTP)
Port 110: Post office protocol v3 (POP3)
Port 113: Authentication service/identification protocol
Port 123: Network time protocol (NTP)
Port 143: Internet message access protocol (IMAP)
Port 443: Hypertext transfer protocol over SSL/TLS (HTTPS)
Port 465: URL Rendesvous Directory for SSM (Cisco)
Port 587: E-mail message submission (SMTP)
Port 993: Internet message access protocol over SSL (IMAPS)
Port 995: Post office protocol 3 over TLS/SSL (POP3S)
Apache Server:QuoteTCP_IN: 80,443
Mail server: QuoteTCP_IN: 25,110,143,587,993,995
TCP_OUT: 25,110
MySQL server (if remote access is required)QuoteTCP_IN: 3306
TCP_OUT: 3306
FTP server: QuoteTCP_IN: 20,21
TCP_OUT: 20,21
UPD_IN: 20,21
UPD_OUT:20,21
Open necessary ports as per your requirements and enjoy the service .... !!!