A client's developer moves the site to a new host over a weekend, or puts a CDN in front of it, and tells no one. The site keeps answering, so uptime checks stay green. This guide turns on the hosting check so you hear about the move from OctoPing, with the old network and the new one named.
What you need
- A role of Member, Admin or Owner to edit the site and its notifications.
- A site that is working today. The first successful lookup becomes the baseline, and everything after it is compared with that.
Turn on hosting checks
Switch on IP/Hosting Changes
The check is off for new sites. Open the site, choose Edit and switch on the IP/Hosting Changes row. Check every starts at every 6 hours and offers 1 hour, 6 hours, 12 hours, 1 day. A move is noticed at the next lookup, so a shorter interval narrows the gap. Choose Save Changes.
Read the baseline
After the first lookup, the site's IP / Hosting card shows the IP Addresses, the ASN with its organization's name, the CDN field and Hosting Changed: No, with a Stable badge. The ASN is the number of the network that owns the address, such as AS13335 for Cloudflare. Write down what the card says now, because you'll compare it with the alert later.
Turn the alert on for the right notifications
On the site's Notifications page, open a notification or choose Add Notification. Under Alert on, switch on Hosting changes. It's on when you create a notification, and it has its own switch, so a channel for down alerts can stay quiet about moves.
What counts as a move
OctoPing looks up the site's IPv4 and IPv6 addresses, finds the network that owns the first address in the sorted list and compares it with the last lookup that found a network. It sends an alert in three cases.
- The network (ASN) is different from the last successful lookup.
- A CDN appears in front of the site or disappears from it.
- The site switches from one CDN to another.
We ran each situation below through the check on a test site with simulated lookup results and recorded what it did.
| What happened to the site | Alert |
|---|---|
| The first lookup, on a hosting provider | No, it sets the baseline |
| The address changed inside the same network | No, the IP Addresses field on the card shows the new address |
| The lookup couldn't identify a network, then the same provider again | No, a failed lookup doesn't become the baseline |
| Cloudflare appeared in front of the site | Yes, with the CDN named |
| Cloudflare's address rotated | No, same network |
| The site switched from Cloudflare to Fastly | Yes |
| A CDN was removed and the site moved to a host | Yes |
The quiet cases are on purpose. A CDN can rotate its addresses within the same network, and a lookup problem shouldn't read as a migration.
What the alert says
The subject reads Hosting Changed with the site's address. The body names the previous network and the new one, and adds the CDN's name when the new network is a CDN. This is the body from our test, where a site moved from a hosting provider to Cloudflare, with the site replaced and the example ASN left as the documentation range.
Website: https://client.example/
Status: Hosting provider changed
Previous hosting:
ASN: AS64500
Provider: Example Hosting Ltd
New hosting:
ASN: AS13335
Provider: CLOUDFLARENET (CDN: cloudflare)
Last checked: <time of the check>
The website appears to have moved to a different hosting provider.
View details in OctoPing: <link to the site>Know the limits before you rely on it
- Behind a CDN, you see the CDN. If the client's origin server moves and the CDN stays in front, the address visitors reach doesn't change, so this check has nothing to compare.
- CDNs are recognized by network number from a built-in list. The list includes the big clouds, so a site served straight from an AWS, Google Cloud or Azure address can show as a CDN under that provider's name. The list maps the main AWS network number to the provider name aws_cloudfront, for example.
- Only one address is looked up. A site that spreads across two providers at once can read as either one.
When the alert arrives
Compare the two networks
The email lists the previous and new ASN and provider. If the new one is a name you recognize from the client's plan, the move is probably planned.
Open the hosting history
On the site's IP / Hosting card, choose View hosting history to see the hosting changes found in the site's recent lookups, with the time of each and the old and new network.
Ask the client
Send them the previous and new provider from the alert and ask who made the change. An unplanned move is worth a call.
Read the reference for Checks reference
Last reviewed
Related
- DocsChecks referenceWhat each of the eight checks and heartbeats measures, whether it is on by default, how often it runs and what counts as a failure or a change.
- FeatureHosting change detection for every site you manageGet an alert when a site moves to a different hosting provider or CDN, with the old and new network named. Address changes inside one network stay quiet.
- FeatureDNS change monitoring for nameserver and MX recordsGet an alert when a domain's nameservers or mail routing change, with the previous and new records side by side.