In this week’s episode of Two-Minute Tech Tuesday, we'll talk about the PROXY protocol. The PROXY protocol transports client connection information across multiple proxy servers. It's used by Varnish to facilitate TLS termination. It's not a replacement for HTTP, in fact it operates on a different layer of the network stack, and comes as a preamble that is prepended to request data.

HAProxy’s proxy protocol has been supported as part of Varnish 4.1 for a few months now. The proxy protocol's main purpose is to transport client connection information from the originating source requesting the connection. It adds a small header about the origin connection.