# Can I monitor Cloudflare sites?

Yes, Cloudflare sites work out of the box. There are a few things worth knowing though, especially if you want real visibility into your origin server and not just the Cloudflare edge.

## If your WAF is blocking us

Our monitoring IPs are fixed and published. You can whitelist them (and our user agent) in a few clicks. We have a step-by-step guide for Cloudflare specifically:

- [How to whitelist Oh Dear static IPs or User Agent in Cloudflare](/docs/faq/how-to-whitelist-oh-dear-static-ips-or-user-agent-in-cloudflare)

Our crawler also identifies itself with [a clear user agent](/docs/faq/what-is-the-oh-dear-crawler-doing-in-my-logs), which makes rule-writing straightforward.

Note: if Cloudflare is proxying traffic to your origin (the typical setup), your origin's access logs will show Cloudflare's IPs, not ours. That's a Cloudflare-side thing, not an Oh Dear thing.

## Monitor Cloudflare **and** your origin

It's a good idea to monitor your site twice:

1. **Through Cloudflare**, the way your visitors reach it.
2. **Directly against your origin**, using a secret query string or custom header that Cloudflare is configured to always forward (no caching).

That way, you'll catch the scenarios where Cloudflare is happily serving a cached response while your backend is down. More detail in our guide on [how to monitor the origin server](/docs/faq/how-can-i-monitor-the-origin-server).

## A handy side effect: a warmer cache

Our broken links crawler visits every page on your site at least once a day. If you sit behind Cloudflare or Varnish, that's a free side effect: every page gets touched, which keeps your cache primed and fresh for real visitors. A nice little bonus on top of the broken link check itself.