Allow our probe
If a firewall, a bot filter or a rate limit in front of your site turns our checks away, your Monitor tells you the site is down when it is not. This page says how to recognize our checks and let them through.
What our checks send
Section titled “What our checks send”Every request of a Website Monitor carries our User-Agent, Mozilla/5.0 (compatible; uup/1.0; +https://uup.dev/probe), and an x-uup-check header that names the Check it comes from.
Anybody can copy a header. A rule that lets requests through by their User-Agent or by x-uup-check lets through anybody who sends it, so allow our addresses instead where your tool can.
Where they come from
Section titled “Where they come from”Our checks come only from these addresses, one server in each location. The list last changed on . When an address is added or replaced, the list changes before the new one sends its first request.
| Location | Name | Addresses |
|---|---|---|
| New York | us.probe.uup.dev | 194.113.73.1082605:7380:8000:1000:b0a1:fcff:fe31:4439 |
| San Jose | us-sjo.probe.uup.dev | 209.50.61.332604:ed40:1000:1711:b0a1:fcff:fe31:617f |
| Frankfurt | de.probe.uup.dev | 85.9.207.572a04:3542:1000:910:b0a1:fcff:fe31:2cdb |
| Helsinki | fi.probe.uup.dev | 80.47.224.1642a04:3540:1000:310:b0a1:fcff:fe31:1fc9 |
| Singapore | sg.probe.uup.dev | 213.163.193.1522a04:3543:1000:2310:b0a1:fcff:fe31:7791 |
The same addresses are at ips.txt, one per line, for a script that keeps an allowlist current. Each one’s reverse DNS names a host under probe.uup.dev, which leads back to the same address, so you can check that a request in your log came from us.
Let them through
Section titled “Let them through”Our probe is a Cloudflare verified bot: see its entry in Cloudflare Radar’s bots directory. If your Cloudflare rules still block it, or another service guards your site, let our checks through this way:
- Allow requests from every address above, the IPv6 ones as well as the IPv4 ones.
- Skip bot checks and rate limits for them.
- Watch your Monitor’s next checks, which show whether every location gets through.
Our probe’s own page, uup.dev/probe, has the steps for each service, for the firewalls, bot filters and web servers sites use most.