Troubleshooting
Solutions to common issues and frequently asked questions about Uptime Monitor.
Firewall Configuration
Whitelisting Uptime Monitor IP Addresses
If your server is behind a firewall, you'll need to whitelist our monitoring IP addresses to allow checks to reach your services.
Get Current IP List:
curl https://uptime-monitor.io/web_api/checker_ip_addressesThis endpoint returns all checker IPs grouped by region in plain text format.
Common Firewall Rules:
iptables (Linux):
iptables -A INPUT -s CHECKER_IP -p tcp --dport 443 -j ACCEPTufw (Ubuntu):
ufw allow from CHECKER_IP to any port 443AWS Security Group:
Add inbound rule: HTTPS (443) from CHECKER_IP/32Important: Our IP addresses may change as we add new regions. Check the endpoint periodically for updates.
Reducing False Positives
False positives can cause alert fatigue. Here's how to minimize them:
1. Configure Multiple Regions
Enable checks from multiple regions for better reliability:
- • Reduces impact of regional network problems
- • Faster failure detection with more check points
- • Provides geographic redundancy
2. Adjust Timeout Settings
Set realistic timeout values based on your service's normal response times:
Recommended: Set timeout to 3-5x your average response time
Example: If average is 500ms, use 1500-2500ms timeout
3. Understand Fail Threshold
Monitors require multiple consecutive failures before alerting:
- • Default: 2 consecutive failures required
- • Checks from any region count toward threshold
- • One successful check marks monitor as UP
Email Notification Issues
Not Receiving Emails?
- 1.Check spam/junk folder
Emails from alert@m.uptime-monitor.io may be filtered
- 2.Whitelist our domain
Add uptime-monitor.io to your email whitelist
- 3.Verify contact email
Ensure the email address in your contact is correct
- 4.Test email delivery
Send a test notification from contact settings
Tip: Send a test notification from the contact settings to verify email delivery is working.
SSL Certificate Validation
Common SSL Issues
Certificate Chain Errors
Ensure your server sends the complete certificate chain:
- • Include intermediate certificates
- • Order certificates correctly (server → intermediate → root)
- • Use SSL checker tools to validate configuration
Self-Signed Certificates
Uptime Monitor validates certificates against trusted CAs:
- • Self-signed certificates will fail validation
- • Use Let's Encrypt for free trusted certificates
- • Consider disabling SSL validation for internal services
Expiration Warnings
Enable "Warn about SSL expiration" to receive alerts at 30, 14, 7, and 1 day before certificate expiry.
Timeout Configuration
Setting Appropriate Timeouts
Timeout settings significantly impact monitoring accuracy:
Recommended Timeout Values:
Factors to Consider:
- • Geographic distance from checker regions
- • Server processing time under load
- • Network latency variations
- • CDN or caching layers
Monitor Status Accuracy
Understanding Monitor Status
Status Determination
Monitor status is based on recent check results:
- • UP: At least one recent check succeeded
- • DOWN: Multiple consecutive failures (based on fail threshold)
Response Time Calculations
Response times are averaged across all successful checks from different regions to provide a global performance metric.
Note: Status updates reflect immediately after checks complete. The fail threshold determines how many failures are needed before marking as DOWN.
Still Need Help?
If you're experiencing issues not covered here, we are ready to assist.