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.
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 and our friends at Nginx) 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.
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.
X-Loadster-Userheader. You can enable this header in Settings and many WAFs can be configured to bypass traffic flood protection when such a header is included with the request.
If none of the workarounds work for you, please contact firstname.lastname@example.org to discuss getting a special cluster set up just for you with a fixed IP address. Due to the additional costs and complexity imposed by our cloud providers, we can only configure fixed IPs for our paying customers at this time, and there might be some additional charges.