Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am making calls from an ec2 instance to a third party web service (over which I have no control). I would like to be able to scale horizontally, so that I can make these calls from multiple ec2 instances, but the web service I'm calling whitelists my IP, and for the sake of discussion let's assume I can't get another IP address whitelisted.

How can I send requests from 2+ machines that appear to the web service to be from the same IP address? Thanks!

share|improve this question
What would most likely be the bottleneck resource that would require more instances? CPU, memory, network? – Dusan Bajic Sep 4 '12 at 18:21
Probably memory would be the first to matter (and then cpu). – Brad Sep 4 '12 at 18:28
Well, then +1 for the Brents answer (move to VPC and use NAT instance) – Dusan Bajic Sep 4 '12 at 18:31
Isn't this basically what a load balancer does for you? – mdpc Sep 4 '12 at 19:17

It sounds like you are really looking for some sort of NAT translation within EC2. I'm not sure if you can set this up with simple EC2 instances but I know they offer it as part of their VPC offering

share|improve this answer

You can create a proxy server and send requests through that proxy server to the web services server. Or VPC NAT is other option for you

share|improve this answer
Thanks for the reply! Do you have any idea how to set up such a proxy server? We use apache for load-balancing internally (which I believe makes it a reverse proxy?), any idea if I can use apache to solve this problem? For example, a single apache box which has the whitelisted IP, and many boxes sending requests through that box to the 3rd-party service? – Brad Sep 20 '12 at 16:14

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.