Support Home > Developers > Hosting Reference Documentation

Hosting Reference Documentation

This page provides some technical information and guidelines about using our products for network administrators, server admins, and web hosts. 

Here are helpful Jetpack troubleshooting links particularly relevant for hosting providers:

Jetpack Basics


Find Help

Download a printable PDF of these Jetpack links.

Jetpack-Specific System Requirements

Read more about Jetpack’s Server Requirements. Don’t worry—it is virtually the same as what WordPress expects.

XML-RPC Support: and Jetpack

XML-RPC is used by Jetpack to connect sites to Some hosts and plugin developers believe that blocking access to /xmlrpc.php will stop various hacking attempts. However, XML-RPC support has been built into WordPress core since version 3.5 and is a stable tool.

Jetpack, much like other plugins, services, and apps (like our mobile apps), relies on the XML-RPC API to communicate with If this is blocked, your Jetpack connection will not work correctly. To learn more about how Jetpack uses XML-RPC, see our support article about Jetpack and XML-RPC.

Allowlist IPs

You should be able to protect a site’s XML-RPC file without having to allowlist specific IP ranges. The most popular hosts out there use tools like fail2ban or ModSecurity, for example. If you opt to allowlist our IP addresses, please see our instructions on how to add our IPs to an allowlist for Jetpack and VaultPress.


In order for a blog or forum to use Akismet to check spam, it needs to be able to make outgoing TCP connections to servers at If your network normally blocks outgoing connections from your public web servers, you’ll need to add a firewall rule permitting connections to Akismet.

If your security filters allow exceptions based on hostnames, you should permit connections on port 80 to these:

  • *

Most Akismet API calls will be made to a hostname of the form, where api_key is an alphanumeric string that is different for each website owner.

If your security filters only allow IP-based rules, please refer to the the list of current IP addresses.

Akismet Specific System Requirements

Akismet is a spam filtering service. It’s most commonly used with WordPress but is often used with other blog platforms, forum applications, contact forms, and similar web apps. It’s a centralized service, so TCP connectivity to servers at is required for it to work.

System requirements for the WordPress plugin are the same as for WordPress, plus:

  • PHP’s fsockopen and gethostbynamel functions must not be disabled (they are enabled by default in PHP).
  • TCP connectivity to

System requirements for other Akismet plugins and implementations vary, but TCP connectivity is always required.

  • Table Of Contents

  • Categories

  • Contact Us

    Need more help? Feel free to contact us.