The HowlOps monitoring bot

If you found this page in your access logs, one of your own customers asked us to check that their site is up. We are an uptime monitoring service, and the traffic you are seeing is that check.

What it does

It makes a single request to one URL that a customer of ours configured, and records whether it answered, how long it took, and the status code. It does not crawl. It does not follow links, read your sitemap, index content, or fetch assets. One request, one URL, on a schedule.

How often

The customer chooses the interval, most commonly once a minute. When they have asked for checks from more than one part of the world, you will see one request per interval from each of those regions. If a check fails we may retry it shortly afterwards to tell a real outage from a blip.

Where it comes from

These are the addresses we probe from. Allowlist them if our checks are being blocked. The same list is available as JSON at /api/v1/public/probers so a firewall rule can consume it directly.

How to block it

Block the addresses above and the checks will stop reaching you. We would rather you did that deliberately than have a WAF do it silently, because a silent block looks like an outage to our customer: they get paged, they call you, and nothing was ever wrong. If you would prefer we stop entirely, write to us and we will take the target off our fleet.

What we will not do

We do not disguise our traffic. We do not rotate through residential addresses, forge browser fingerprints, or solve challenges meant to keep bots out. A monitor that works only by outsmarting your bot management is not measuring whether your site is up, and it would break on a schedule neither of us controls.