Systems and methods for client IP address insertion via TCP options

The present disclosure presents systems and methods for maintaining identification of network devices sending or traversing a network packet en route to an intermediary device deployed between a source and a destination network device. An intermediary may receive an acknowledgement packet comprising an option field identified by an option number for a transport layer connection established via the intermediary, comprising overlay network data that identifies IP addresses of the originating network device and host network devices intercepting and forwarding the network packet to the intermediary, and may determine the option number for the option field from which to obtain the overlay network data identifying IP addresses. The intermediary device may receive a second request of the client to access the server via the transport layer connection and insert IP addresses from the overlay network data into an application layer protocol header of the second request forwarded to the server.