Last modified: September 15, 2023

Overview

Use the Host Access Control interface to allow, reject, or drop access to the following services for specific IP addresses:

• cPanel
• WHM
• Webmail
• Web Disk
• FTP
• SSH
• SMTP
• POP3
• IMAP

To control access on servers that use AlmaLinux OS, Rocky Linux™, or CloudLinux™, you must control service access by port number. For a list of ports and their related services, read the Ports section of the How to Configure Your Firewall for cPanel Services documentation.

You can control access by service on servers that run Ubuntu®.

Host Access Control for AlmaLinux, Rocky Linux, and CloudLinux

Add a rule

To allow or deny a single IP address, comma-separated list of IP addresses, or CIDR subnet mask access to a service, perform the following steps:

1. Enter the port number in the Port text box.
2. Enter the IP address, CIDR subnet mask, or comma-separated IP address list in the IP Address/CIDR text box.
   • You may enter wildcards in this text box.
   • You do not need to enclose IPv6 addresses in square brackets ( [ ] ).
   • You may apply your rule to multiple IP addresses by entering a comma-separated list of IP addresses or a CIDR subnet mask.
   • To add the CIDR subnet mask, add /NUMBER to your IP address, where NUMBER is the number of network bits that an IP address must match to be affected by your rule.
     • IPv4 example: 192.168.0.0/24 means the first 24 bits of the requesting IP address (the first, second, and third numbers in the IP address) must match the rule IP address. This will result in all IP addresses in the range of 192.168.0.1 - 192.168.0.254 meeting the rule.
     • IPv6 example: 2001:0db8:0:0:1:0:0:1/64 means that the first 64 bits of the requesting IP address must match the rule IP address. Because IPv6 uses 128-bit addresses, this will result in all IP addresses in the range of 2001:db8:abcd:0012:0000:0000:0000:0000 - 2001:db8:abcd:0012:ffff:ffff:ffff:ffff meeting the rule.
3. Select the TCP protocol or the UDP protocol from the Protocol menu.
4. Select which action to take for the port from the Action menu.
   • Use the ACCEPT action to allow the IP addresses in the range to access the port.
   • Use the DROP action to block the IP addresses in the range without a rejection message.
   • Use the REJECT action to block the IP addresses in the range with a rejection message.
5. Click Add Rule to add the rule. The rule will appear in the Current Rules table and apply.

Example

To allow access for two IP addresses, but deny access from all other addresses, use either of the following methods:

• Create two separate rules:
  • Create one rule that accepts 192.168.0.0/24 or 2001:0db8:0:0:1:0:0:1/64 with the following steps:
    1. Enter the port number in the Port text box.
    2. Enter 192.168.0.0/24 in the IP Address/CIDR text box.
    3. Select the TCP protocol from the Protocol menu.
    4. Select ACCEPT from the Action menu.
    5. Click Add Rule to add the rule. The rule will appear in the Current Rules table.
  • Create a second rule that rejects access to ALL addresses with the following steps:
    1. Enter the port number in the Port text box.
    2. Enter ALL in the IP Address/CIDR text box.
    3. Select the TCP protocol from the Protocol menu.
    4. Select REJECT from the Action menu.
    5. Click Add Rule to add the rule. The rule will appear in the Current Rules table.
• Or, create one rule that accepts all except 192.168.0.0/24 or all except 2001:0db8:0:0:1:0:0:1/64 with the following steps:
  1. Enter the port number in the Port text box.
  2. Enter all except 192.168.0.0/24 or all except 2001:0db8:0:0:1:0:0:1/64 in the IP Address/CIDR text box.
  3. Select the TCP protocol from the Protocol menu.
  4. Select ACCEPT from the Action menu.
  5. Click Add Rule to add the rule. The rule will appear in the Current Rules table.

Host Access Control for Ubuntu

Use the Host Access Control to allow or deny (block) access to the following services for specific IP addresses:

• cPanel (cpaneld)
• WHM (whostmgrd)
• Webmail (webmaild)
• Web Disk (cpdavd)
• FTP (ftpd)
• SSH (sshd)
• SMTP (smtp)
• POP3 (pop3)
• IMAP (imap)

Allow or deny access

To allow or deny a single IP address, comma-separated list of IP addresses, hostname, or CIDR subnet mask access to a service, perform the following steps:

1. Enter the service name in the daemon text box.
2. Enter the IP address, CIDR subnet mask, comma-separated list of IP addresses, or hostname in the Access List text box.
   • You may enter wildcards in this text box.
   • You must enclose IPv6 addresses in square brackets ( [ ] ).
   • To add a CIDR subnet mask, add /NUMBER to your IP address, where NUMBER is the number of network bits that an IP address must match for your rule to affect it.
     • IPv4 example: 192.168.0.0/24 means the first 24 bits of the requesting IP address (the first, second, and third numbers in the IP address) must match the rule IP address. This will result in all IP addresses in the range of 192.168.0.1 - 192.168.0.254 meeting the rule.
     • IPv6 example: 2001:0db8:0:0:1:0:0:1/64 means that the first 64 bits of the requesting IP address must match the rule IP address. Because IPv6 uses 128-bit addresses, this will result in all IP addresses in the range of 2001:db8:abcd:0012:0000:0000:0000:0000 - 2001:db8:abcd:0012:ffff:ffff:ffff:ffff meeting the rule.
3. Enter the desired action in the Action text box.
   • Enter allow to allow access.
   • Enter deny to deny access.
4. Describe the rule in the Comment text box.
5. Click Save Host Access List, or click Reload to delete any changes. Any saved rules apply.

Example

To allow access for two IP addresses, but deny access from all other addresses, use either of the following methods:

• Create two separate rules:
  1. Create one rule that allows 192.168.0.0/24 or 2001:0db8:0:0:1:0:0:1/64.
  2. Create a second rule that denies access to ALL addresses.
• Create one rule:
  1. Enter all except 192.168.0.0/24 or all except 2001:0db8:0:0:1:0:0:1/64 in the Access List text box.
  2. Enter deny in the Action text box.