P4-FILB: Stateless Load Balancing Mechanism in Firewall and IPv6 Environment with P4

Load balancers are critical infrastructure in modern distributed systems, and their main function is to evenly distribute client traffic to multiple servers for high availability and scalability. However, current load balancers face challenges in balanced resource utilization. To ensure per-connection consistency, load balancers typically assign subsequent requests from the same client to the same server. While this strategy simplifies session management and reduces the overhead of state synchronization, it also leads to uneven resource utilization.In this paper, we propose P4-FILB, a stateless load balancing scheme that achieves uniform load distribution among servers so that the resources of each server can be optimally balanced when receiving a large number of data streams. The key idea behind the implementation of P4-FILB is that a load balancer between the client and the server keeps track of the size of the packets that are currently being processed by the different servers. It also uses segment routing in IPv6, which uses an ordered list called "segments" to direct packets to servers that are currently utilizing a relatively small amount of resources. And this paper also proposes a two-tier load policy in firewall environment. According to the intelligent routing policy of the firewall, the packets are distributed to different groups of servers, and then the load balancer carries out further request allocation to improve the allocation of network resources. After evaluating the performance of P4-FILB, it is shown that the load balancing scheme performs better than the existing studies in terms of load balancing state between servers. It also reduces the overhead caused by extra packets by means of packets carrying connection information.