Routing Gets Personal: Welcome to /32 to the client

No matter which network architecture or topology is used, large Layer 2 domains can be found everywhere. They are also used in campus networks to connect end devices and segment them appropriately into their own broadcast domains. However, using extended L2 domains also brings all the restrictions, disadvantages and behaviour patterns belonging to this layer into the network environment. These include the limitations of the Spanning Tree Protocol, the poor scalability of L2 networks, and the flooding of broadcast, unknown unicast and multicast (BUM) network traffic. The bachelor's thesis investigates a novel approach to circumvent these issues, referred to as the «/32 environment», which aims to minimize the size of Layer 2 domains as much as possible. This is achieved by assigning a /32 subnet mask to each end device alongside its IP address. Consequently, each end device operates within its own network, resulting in a Layer 2 domain containing only a single IP address. This solution follows the idea of extending Layer 3 down to the end device. The approach was validated by establishing a physical test environment (Cisco) and a virtual test environment based on «containerlab» (Arista). It gave the possibility to test various scenarios and network protocols. These experiments have verified the technical feasibility of this approach and its associated advantages. In addition, all tested protocols perform correctly in a /32 environment. Currently, however, this approach cannot meet the requirements of a campus network as the router OS from Arista and Cisco either has bugs or lacks the necessary functions. Future studies could examine how such an implementation would perform in WLAN infrastructures or data centres, and the challenges that might arise.