SSED: Servers Under Software-Defined Network Architectures to Eliminate Discovery Messages Emad Alasadi and Hamed S. Al-Raweshidy Abstract—The high speed, low cost, sharing of peripheral devices and central administration features of the Ethernet have led to it being widely trusted as the backbone for recent networks. However, it suffers from many practical limitations leading to a lack of scalability, owing to its broadcast and multicast mechanisms, particularly in relation to the discovery processes. Whilst software-defined networks (SDN) have overcome many legacy network problems, scalability remains a major issue, because broadcasting and multicasting have been inherited. Moreover, the problem is exacerbated with increasing network traffic, which results in higher bandwidth consumption, congestion, and increased probability of a single point of failure. To address this, servers under software-defined network architectures to eliminate discovery messages (SSED) is designed in this paper, and a backbone of floodless packets in an SDN LAN network is introduced. For SSED, flood discovery packets created by the dynamic host configuration protocol in the application layer and the address resolution protocol in the data link layer are considered, respectively. SSED eliminates any broadcast discovery packets with better performance, lowers peak overhead, and introduces an innovative mechanism for defining the relationship between the servers and SDN architecture. Experimental results after constructing and applying an authentic testbed verify that our proposed model has the ability to improve the scalability by removing broadcast packets from the data plane, reduction of control packets in the control plane, lessening peak overhead on the controller, preventing it experiencing failed requests, offering better response time, and providing more efficient performance. Index Terms—Software-defined networks, scalability, broadcast, servers. ### I. INTRODUCTION The Ethernet is the most popular technology in local area networks that can be found in small geographic zones, such as in the home, on campuses and in enterprise network. It allows for the sharing of resources with high performance, which supports virtualization principles and the client-server scheme in relation to the distribution of load among the servers as well as assisting in administration. The Ethernet protocol resides in the data link layer in the Internet protocol suite, providing services for its own layer and up layer protocols, such as broadcast ones like the Address Resolution Protocol (ARP) in the data link layer and the Dynamic Host Configuration Protocol (DHCP) in the application layer. It also services multicast protocols, such as the Bridge Protocol Data Units (BPDUs), which is a multicast packet used by the Spanning Tree Protocol (STP) in the link layer and the Multicast Listener Discovery (MLD) protocol in the internet layer. Despite broadcast and multicast protocols having the advantage of providing different services, such as getting destination MAC addresses, obtaining new IPs, loop free networking and discovering neighbouring nodes, the compulsory broadcast mechanism has resulted in multiple negative consequences that motivated us to design our model, which are as follows. - As a consequence of broadcast packets, broadcast storms canSSED: Servers Under Software-Defined Network Architectures to Eliminate Discovery Messages Emad Alasadi and Hamed S. Al-Raweshidy Abstract—The high speed, low cost, sharing of peripheral devices and central administration features of the Ethernet have led to it being widely trusted as the backbone for recent networks. However, it suffers from many practical limitations leading to a lack of scalability, owing to its broadcast and multicast mechanisms, particularly in relation to the discovery processes. Whilst software-defined networks (SDN) have overcome many legacy network problems, scalability remains a major issue, because broadcasting and multicasting have been inherited. Moreover, the problem is exacerbated with increasing network traffic, which results in higher bandwidth consumption, congestion, and increased probability of a single point of failure. To address this, servers under software-defined network architectures to eliminate discovery messages (SSED) is designed in this paper, and a backbone of floodless packets in an SDN LAN network is introduced. For SSED, flood discovery packets created by the dynamic host configuration protocol in the application layer and the address resolution protocol in the data link layer are considered, respectively. SSED eliminates any broadcast discovery packets with better performance, lowers peak overhead, and introduces an innovative mechanism for defining the relationship between the servers and SDN architecture. Experimental results after constructing and applying an authentic testbed verify that our proposed model has the ability to improve the scalability by removing broadcast packets from the data plane, reduction of control packets in the control plane, lessening peak overhead on the controller, preventing it experiencing failed requests, offering better response time, and providing more efficient performance. Index Terms—Software-defined networks, scalability, broadcast, servers. ### I. INTRODUCTION The Ethernet is the most popular technology in local area networks that can be found in small geographic zones, such as in the home, on campuses and in enterprise network. It allows for the sharing of resources with high performance, which supports virtualization principles and the client-server scheme in relation to the distribution of load among the servers as well as assisting in administration. The Ethernet protocol resides in the data link layer in the Internet protocol suite, providing services for its own layer and up layer protocols, such as broadcast ones like the Address Resolution Protocol (ARP) in the data link layer and the Dynamic Host Configuration Protocol (DHCP) in the application layer. It also services multicast protocols, such as the Bridge Protocol Data Units (BPDUs), which is a multicast packet used by the Spanning Tree Protocol (STP) in the link layer and the Multicast Listener Discovery (MLD) protocol in the internet layer. Despite broadcast and multicast protocols having the advantage of providing different services, such as getting destination MAC addresses, obtaining new IPs, loop free networking and discovering neighbouring nodes, the compulsory broadcast mechanism has resulted in multiple negative consequences that motivated us to design our model, which are as follows. - As a consequence of broadcast packets, broadcast storms can