Prerequisites

Before setting up SMS alerts, ensure you meet the following requirements:

• Administrative Access: You need admin privileges in Nagios XI to configure settings.
• Valid Mobile Number: Provide a working phone number for SMS delivery.
• Carrier Compatibility: Your mobile carrier must support email-to-text messaging (e.g., Verizon: number@vtext.com, T-Mobile: number@tmomail.net). Check your carrier’s SMS gateway details online. Please note the AT&T email to text services were discontinued on June 17, 2025.
• Nagios XI 2025 Installed: This guide assumes you’re using the latest version, released with enhanced notification options.

How SMS Alerts Work in Nagios XI

Nagios XI sends SMS alerts via email-to-text functionality. When an alert is triggered, Nagios XI sends an email to the mobile carrier’s SMS gateway using the format:

xxxxxxxxx@your_carrier.yyy

where xxxxxxxxx is the user’s mobile number. The carrier must support email-to-text services for this feature to function properly.

Configuring SMS Alerts

Step 1: Define Notification Preferences

1. Log in to Nagios XI and click your Profile in the top-right corner of the navigation bar.
2. Select Notification Preferences.
3. Check the Enable Notifications box to activate alerts for your account.
4. Click the Mobile Text (SMS) tab.
5. Choose the alert types you want to receive (e.g., Host Down, Service Critical, Recovery). Options include:
   • Host Acknowledgment
   • Service Warning
   • Host Unreachable
   • Service Downtime
6. Click Update Settings to save your selections.

Tip: Tailor notifications to avoid alert fatigue—focus on critical events like “Service Critical” or “Host Down.”

Step 2: Enable SMS Notifications

1. Go to Notification Methods.
2. Click the Mobile Text (SMS) tab.
3. Ensure the Receive text alerts to your cellphone box is checked.
4. Enter your mobile number and select your mobile carrier.
5. Click Update Settings.

Step 3: Verify Your Phone Number

1. In the Notification Methods tab, click Send Verification Key.
2. Check your phone for an SMS containing a verification key (valid for 10 minutes).
3. Enter the key in the provided field and click Verify.
4. Once successful, a green tick appears next to your number, indicating verification.
5. Check the Receive text alerts to your cellphone box and click Update Settings.

Step 4: Customize SMS Messages

1. Go to Notification Messages in your Profile.
2. Click the Mobile Text (SMS) tab.
3. Edit the message format using Nagios XI variables (e.g., $HOSTNAME$, $SERVICESTATE$) for concise, actionable alerts. Example:
   • Default: $HOSTNAME$ is $HOSTSTATE$
   • Custom: ALERT: $HOSTNAME$ DOWN at $DATETIME$
4. Keep messages short (under 160 characters) to avoid truncation by carriers.
5. Click Update Settings.

Resource: See the Understanding Notification Variables in Nagios XI for customization options.

Step 5: Managing Mobile Carriers

If your carrier is not listed:

1. Go to Admin > System Config > Manage Mobile Carriers.
2. Add or edit a mobile carrier based on your requirements.
3. Click Update Settings to save changes.

Troubleshooting

• If SMS notifications are not received, ensure the mobile number and carrier are correctly entered.
• If the verification process fails, request a new verification key and retry.
• If your carrier does not support email-to-text messaging, consider using third-party SMS gateways.

Conclusion

By following this guide, you can successfully configure SMS alerts in Nagios XI, ensuring timely notifications for critical system events. For further assistance, visit the Nagios Support Forum or the Nagios Knowledgebase.