Configuring Your Server With A Static IP Address

Assigning a static IP address to your Nagios application server is a great best practice to help ensure monitoring continuity and stability.

Outlining the specific steps to set a static IP on supported operating systems is beyond the scope for our documentation, but this article provides Nagios tool-specific settings to be aware of, as well as links to external resources that may be helpful.

External Resources

RHEL | Oracle | CentOS Stream

Setting a Static IP in RHEL | CentOS | Oracle using nmcli

Debian

Setting a Static IP in Debian

Ubuntu

This link explains how to configure your static IP using the config file located in the /etc/netplan directory.

Setting a Static IP in Ubuntu using netplan

Nagios Specific Settings

If you change the IP address of your server after you've installed a Nagios application, there are a few things you may need to do and verify.

Nagios Fusion Settings

After changing the IP address on your server you should check that the Program URL is correct in:

Admin > System Config > Manage System Config > General Program Settings

If a DNS entry is used make sure that this resolves to your new IP address.

Nagios Log Server Settings

You can learn more about changing the IP address of Nagios Log Server instances here:

Changing Log Server Cluster Instance IP Addresses

After changing the IP address on your server you should check that the Interface URL is correct in:

Admin> General >Global Settings

If a DNS entry is used make sure that this resolves to your new IP address.

Nagios Network Analyzer Settings

After changing your Network Analyzer server's IP address, you'll need to reconfigure any pre-existing flow sources to point at the new address. Changes aren't required in the Network Analyzer source settings, but the settings on the sources themselves must be updated.

Nagios XI Settings

• Program URL

After changing the IP address on your server you should check that the Program URL is correct in:

Admin > System Config > System Settings> General tab

If a DNS entry is used make sure that this resolves to your new IP address.

• localhost Entry In /etc/hosts

It has been observed that sometimes the system-config-network or nmtui tool removes the localhost entries from the /etc/hosts file.

Edit your /etc/hosts file and make sure there are localhost entries. For example:

127.0.0.1    localhost.localdomain    localhost.localdomain    localhost4    localhost4.localdomain4    localhost    xi-c6x-x64 ::1    localhost.localdomain    localhost.localdomain    localhost6    localhost6.localdomain6    localhost    xi-c6x-x64

Troubleshooting

After you change the IP address and reboot the server you find that the interface is in the DOWN state.

The following line needs changing in the config file:

ONBOOT=no

To:

ONBOOT=yes

Final Thoughts

For any support related questions please visit the Nagios Support Forums at:

Nagios Support Forums