# Can I get Loadster's IP addresses for my whitelist?

> Is your firewall or load balancer blocking traffic based on IP address? Here's how to get Loadster's IP addresses so you can whitelist them.

Source: https://loadster.com/faqs/whitelist-load-test-ip-addresses/

Loadster spins up on demand cloud instances to run your load test, so we normally won't know the IP addresses
ahead of time. Most of our customers actually prefer this since it's best to simulate load from many different locations
at once (for a more realistically distributed test), and it allows them to properly exercise load balancers that do
round robin IP-based load balancing.

However, if your situation requires that you know Loadster's IP addresses ahead of time, we might have a solution for
you.

## When is IP whitelisting necessary?

If you're testing a private application behind a firewall, you may want to whitelist certain IP addresses to allow
the Loadster traffic to reach the application.

Also, some load balancers and web application firewalls (including those made by [Cloudflare](https://cloudflare.com)
and [Nginx](https://www.nginx.com/)) have a DDoS protection feature that watches for a large
flood of traffic from the same IP address, and blocks or throttles subsequent traffic from it.

## What are some alternatives to IP whitelisting?

There are a few other things you might want to explore before going to the trouble of requesting fixed Loadster IPs
and setting up a whitelist.

* Configure your load balancer or firewall to allow requests with a special header, and then add a
  [code block](https://loadster.com/manual/code-blocks/) at the beginning of your script to set the header globally.
  For example, `http.setGlobalHeader('X-Loadster', 'true')` would set a header for Protocol Bots, or
  `browser.setGlobalHeader('X-Loadster', 'true')` would set it for Browser Bots. When the bots run your script,
  all requests will include that header, so your firewall can allow the traffic.
* Disable the IP blocking feature on your application firewall temporarily. If it's a production site, you might get
  some pushback from your team, but then again if you are load testing in production we'll assume everyone is on the
  same page already!
* Host your own [Loadster Engine](https://loadster.com/manual/testing-with-loadster-engine/) on an IP (or multiple IPs)
  of your choosing, rather than the on demand Loadster Cloud regions. This may be the easiest option and you'll have
  full control of the IPs and environments that way, but it might be prohibitively complicated from an operational
  standpoint if you are running a large load test that requires many engines.

## Can I just whitelist entire AWS or GCP regions?

Since Loadster launches cloud instances on demand from [AWS and GCP cloud regions](https://loadster.com/manual/cloud-regions/), 
one option might be to whitelist their entire external IP address ranges. 

Whitelisting such a large range has its obvious drawbacks, but if you want to go 
down that road you could obtain the list of [AWS IP Addresses](https://ip-ranges.amazonaws.com/ip-ranges.json) 
or [GCP IP Addresses](https://www.gstatic.com/ipranges/cloud.json) and simply whitelist all IPs for any cloud region 
you're load testing from.

## What if I really need to test from a fixed IP address?

If none of the workarounds work for you, please contact [help@loadster.com](mailto:help@loadster.com)
to request a special cluster with a fixed IP address in your region of choice.

Setting this up with our cloud providers incurs some extra cost and complexity, so we might need to pass on 
the additional costs and/or charge a setup fee, and it might require 1-2 days lead time.