In the modern landscape, robust data communication is pivotal for businesses and lifestyles. This has led to intricate demands from enterprise customers for sophisticated communication solutions. As a response, MPLS (Multiprotocol Label Switching) technology is being leveraged to meet these complex connectivity needs. This paper undertakes a comprehensive exploration of intricate MPLS- Virtual Private Networks (VPN) applications. The study entails both in-depth analysis and practical application on an operational network to validate its efficacy. The research primarily delves into diverse models of complex Layer 3 VPNs over MPLS. It commences by elucidating the foundational concept of a simple VPN and subsequently navigates through various designs for deploying Layer-3 VPNs on MPLS networks. MPLS technology has expanded the horizons of VPN services, catering precisely to contemporary business and customer requirements. Beyond conventional peer-to-peer private communication, the technology facilitates sophisticated iterations like managed service VPNs and overlapping VPNs. This paper systematically navigates these intricacies, offering comprehensive insights into their mechanisms and operational feasibility.