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Override DNS Settings In Synthetic Tests

A DNS override lets you point a hostname at a specific IP address when DebugBear loads a page. The site URL stays the same, but the underlying request is routed to the server you choose.

Here are some situations where this is useful:

  • Testing a staging server using the production hostname
  • Bypassing a CDN to test how fast your origin responds directly
  • Validating a planned migration before changing your public DNS records

How to set up a DNS override​

  1. Set up a new monitored page, or open Page Settings for an existing page.
  2. Click Show Advanced.
  3. Open the DNS Overrides section and click Add DNS Override.
  4. Enter a Name, Hostname Pattern and a Target IP
  5. Click Create.

Setting up a DNS override

Hostname pattern​

The pattern is the hostname you want to redirect. It can be:

  • An exact hostname: example.com
  • A wildcard for the leftmost label: *.example.com

You can also include a port to match only that port: example.com:443.

Target​

The target is where the matched requests should be sent. It can be:

  • An IPv4 address: 1.2.3.4
  • An IPv4 address with a port: 1.2.3.4:8080
  • An IPv6 address: 2001:db8::1 (use brackets if you want to specify a port, e.g. [2001:db8::1]:8080)
  • Another hostname: second.example.com

Limitations​

The page's URL still uses the original hostname, so TLS certificates and HTTP Host headers must be valid for that hostname on the target server.

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