Table of contents

IP information & versions

Checkly supports both IPv4 and IPv6. We have a dual stack setup, meaning that we can reach both IPv4 and IPv6 addresses from our check runtime.

Note that for most workloads (API checks, browser checks, etc.) the IPv6 stack is preferred over IPv4. This means that if your endpoint is reachable over IPv6, we will use that. If not, we will fall back to IPv4.

You can actually influence this behaviour in a browser check by passing the --host-resolver-rules flag to a chromium instance. In the code example below, we force the browser to use IPv4, whereas the host dual.tlund.se is reachable over both IPv4 and IPv6.

import { test, chromium } from '@playwright/test'

test('Set host resolver to IPv4', async () => {

  const browser = await chromium.launch({
    args: ['--host-resolver-rules=MAP dual.tlund.se 193.15.228.195']
  });

  const page = await browser.newPage();
  await page.goto('http://dual.tlund.se/')
});

All monitoring traffic from Checkly for all customers on all plans comes from a fixed set of source IPs. An up-to-date list can be requested unauthenticated through the API. See our API spec for more info.

If you are looking to allowlist Checkly traffic, see our docs on allowlisting.

Allowlisting & filtering traffic Responsible use

Last updated on November 6, 2024. You can contribute to this documentation by editing this page on Github