This is a structured reference that maps Linux kernel network sysctl parameters to their specific roles in the packet processing pipeline, from the network interface card through to the application layer. It covers the full path of packet traversal, including interrupt mitigation, buffer management, queuing disciplines, and TCP auto-tuning mechanisms.
The reference details how to configure kernel parameters for connection handling, including TCP listen backlog, SYN queue management, FIN timeout, and syncookies. It also addresses queue management and bufferbloat control through egress queuing disciplines, ring buffer sizing, and ingress backlog limits, alongside TCP buffer tuning with auto-tuning capabilities.
The material covers traffic management for both ingress and egress paths, including hardware interrupt coalescing, NAPI polling cycles, NIC ring buffer resizing, and soft IRQ adjustments. It also provides guidance on TCP congestion control algorithm selection and socket buffer size configuration, with diagnostic commands for inspecting packet drops, queue lengths, interrupt activity, and TCP connection states.