How to Restart Services, Share Multiple IP Addresses, and Configure Service Proxying in cPanel & WHM

1. Restarting Services in cPanel & WHM

You may need to restart a service (daemon) after changing its configuration or when it becomes unresponsive. cPanel & WHM provides multiple ways to restart services safely.

Important: Changing the server hostname temporarily blocks access to the Calendars and Contacts interface. Access is restored automatically after the hostname update completes.

1.1 Restart Services in WHM

Most services can be restarted through:

WHM » Home » Restart Services

1.2 Restart Services from the Command Line

Use the restartsrv script

If WHM cannot restart a service, use the command-line script:

/usr/local/cpanel/scripts/restartsrv_*

Replace * with the service name.

Direct systemctl restart

For CentOS, CloudLinux 7+, AlmaLinux, Rocky, and RHEL:

systemctl restart service-name.service

IPv6 Warning

If you restart the network service, IPv6 addresses may be removed. Restore them with:

/usr/local/cpanel/scripts/restartsrv_cpipv6

1.3 Service Error Logs

If a service fails to restart, check its logs:

• Apache: /var/log/apache2/error_log
• BIND, ProFTP, Pure‑FTP: /var/log/messages
• Exim: /var/log/exim_mainlog, /var/log/exim_rejectlog, /var/log/exim_paniclog
• Dovecot: /var/log/maillog
• MySQL: /var/lib/mysql/hostname.err
• SSH: /var/log/messages, /var/log/secure, /var/log/auth

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2. Sharing Multiple IP Addresses in cPanel & WHM

WHM allows you to configure one or more shared IP addresses for reseller accounts. This is useful for cost efficiency and simplified account management.

2.1 Step 1 — Add and Reserve IP Addresses

1. Log in to WHM as root.
2. Go to Add a New IP Address and add the IPs.
3. Go to Show/Edit Reserved IPs and reserve the IPs for specific resellers.

2.2 Step 2 — Rebuild the IP Address Pool

Navigate to:

WHM » IP Functions » Rebuild the IP Pool

2.3 Step 3 — Create Reseller Accounts

1. Create reseller accounts via Create a New Account.
2. Create packages via Add a Package.
3. Assign privileges via Edit Reseller Nameservers and Privileges.

Warning: Selecting Everything – All Features grants root‑level access to the reseller.

2.4 Step 4 — Change a Reseller’s Shared IP

1. Go to Manage Reseller’s Shared IP.
2. Select the reseller.
3. Choose the shared IP and click Save.

DNS Warning: Coordinate with resellers to avoid downtime when changing IPs.

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3. Service Proxying in cPanel & WHM

Service proxying allows local services to forward requests for a cPanel account’s domains to a remote server. This is useful for distributed hosting setups.

3.1 Supported Services

• Web Server (httpd)
• Mailbox (Dovecot) — IMAP/POP3 only

Note: Exim (SMTP) cannot be proxied, but you can configure manual MX redirects.

4. Service Proxy Configuration Model

Every configuration begins with a general proxy backend server. You may then override specific service groups (e.g., Mail) with different backend servers.

Example:

• General backend: web.example.com
• Mail backend: mail.example.com

5. Set Up Service Proxying (WHM API 1)

5.1 Check Current Proxy Configuration

whmapi1 get_service_proxy_backends username=example

5.2 Set a General Proxy Backend

whmapi1 set_service_proxy_backends username=example general=remote.example.com

5.3 Set a Service Group Backend

whmapi1 set_service_proxy_backends username=example service_group=Mail service_group_backend=mail.example.com

5.4 Confirm Configuration

whmapi1 get_service_proxy_backends username=example

6. Service Proxy Groups

• Mail: Dovecot (IMAP/POP3)

Note: SMTP is not included.

7. Remove Service Proxying

To remove service proxying, unsuspend the account on the source server. This is commonly used after Live Transfer operations.

Conclusion

This guide covers restarting services, configuring shared IP addresses for resellers, and setting up service proxying in cPanel & WHM. These tools help administrators maintain stable services, optimize IP usage, and distribute workloads across multiple servers.