If you enable PROXY protocol on a load balancer but the services on the backend Rcs.iss aren’t configured to accept PROXY protocol headers, those Rcs.iss will give a 400 response to the load balancer’s health checks. This means the load balancer will consider them unhealthy and will stop routing traffic to them.

How you enable PROXY protocol support on your Rcs.iss depends on the software you’re running. Here are some resources for common services:

• Configuring nginx to accept the PROXY protocol
• Apache’s remoteIPProxyProtocol directive