mmproxy - Creative Linux routing to preserve client IP addresses in L7 proxies

The blog post discusses the problem of retaining real client source IP addresses when building an application level proxy, particularly in generic TCP tunnels. It presents three general solutions to this issue and introduces "mmproxy", a PROXY protocol gateway that listens for remote connections coming from an application level load balancer like Cloudflare Spectrum. Mmproxy spoofs the client IP address, making it indistinguishable from a real connection directly connecting to the application. The post also provides instructions on how to set up and run mmproxy.