ipaliases service is offline or keeps restarting

Symptoms

You receive service-failure notifications like the following stating that the ipaliases service has failed:

Server $hostname
Primary IP Address $primary-IP-address

Service Status failed
Notification The service “ipaliases” appears to be down.

And one or more IPs added to the server via WHM >> Add a New IP Address are unresponsive.

Description

If one or more of the server's additional IP addresses added via WHM >> Add a New IP Address cannot be brought online, the ipaliases service will have a 'down' status. The service will restart in an attempt to get the server's additional IPs back online (provided that monitoring is enabled for the 'IP Aliases' service in WHM >> Service Manager).

One cause of this issue is that the server's main IP address has changed, likely due to a modification in networking, causing a conflict with additional IP addresses. It may be necessary to update the server's main IP address in the cPanel software to correct the problem.

Workaround

1. Verify that additional IPs are down via a manual ipaliases service check:

   [root@server]# /scripts/restartsrv_ipaliases --check
   warn [restartsrv_ipaliases] The 'ipaliases' service has determined there are one (203.0.113.1) or more missing IP addresses on the system.
   (XID vs6qfk) The “ipaliases” service is down: The 'ipaliases' service has determined there are one (203.0.113.1) or more missing IP addresses on the system.

2. Run cPanel's mainipcheck script to update the server's main IP. If the conflict described above is the problem, you will likely see output that the main IP has changed and that the additional IP address that could not be brought up by ipaliases is involved:

   [root@server]# /usr/local/cpanel/scripts/mainipcheck
   info [mainipcheck] The Server's main IP address has changed from 203.0.113.1 to 203.0.113.5.
   info [mainipcheck] Scheduled SPF record update

3. Restart ipaliases to bring all additional IPs back online:

   [root@server]# /usr/local/cpanel/scripts/restartsrv_ipaliases

4. Ensure that all additional IPs were brought back online successfully:

   [root@server]# ip -4 a | grep inet