Check locations
Where checks run from, how a monitor is marked down, and which IPs to allow.
Where checks run from
| Location | IP address |
|---|---|
| France | 158.220.122.185 |
| Serbia | 185.119.90.100 |
| Netherlands | 185.119.88.128 |
Checks are sent over IPv4 with the user agent uptime.rs monitor (+https://uptime.rs).
If your sites use a firewall, Cloudflare rules or an IP allowlist, allow these addresses so checks are not blocked.
When is a monitor down?
Every monitor is checked every minute from each location that is on. It is marked down only when every location has failed its last checks in a row (2 by default, see Alert after). If any location reaches the site, it is up. This keeps one location's network problem from raising a false alarm.
Blocked by Cloudflare
Some sites behind Cloudflare challenge or block datacenter IPs. Those checks show as blocked: they are left out of the up/down decision and out of uptime %, because the answer came from Cloudflare, not your site. Allow the IPs above in Cloudflare (Security → WAF → Tools → IP Access Rules) to check the site from every location.
Turning locations off
Under Settings → Check locations you can turn locations off for all your monitors, e.g. if a site blocks one country. At least one stays on.