file /etc/sysctl.d/50-vipnix.conf

50-vipnix.conf

####
## VIPNIX TUNING - System and Network Optimization for High Performance
##
## This file adjusts Linux kernel parameters to maximize performance on 10 Gbps networks,
## reduce packet retransmissions, and improve efficiency on high-load servers.
## Focused on local networks with low latency (1–5 ms), such as connections between Linux servers and macOS clients.
## Values are optimized to minimize packet loss, prioritize low latency, and maximize throughput.

# Increases the maximum number of events that inotify can monitor simultaneously.
# Useful for applications that monitor many files (e.g., file servers, backup tools).
# Value: 524288 allows monitoring up to half a million files, suitable for modern servers.
fs.inotify.max_user_watches=524288

# Sets the maximum limit of pending connections in the socket listening queue.
# Increasing from 128 (default) to 2048 supports more simultaneous connections, ideal for web or proxy servers.
net.core.somaxconn=2048

# Increases the maximum limit of open file descriptors in the system.
# A value of 100000 supports applications with many connections (e.g., database servers, proxies).
fs.file-max=100000

# Reduces the kernel’s tendency to move idle processes to swap (default = 60).
# A value of 10 prioritizes keeping data in RAM, improving performance on servers with large memory.
vm.swappiness=10

# Expands the range of ephemeral ports available for outgoing connections.
# Range 1024–65535 maximizes the number of simultaneous connections, essential for network servers.
net.ipv4.ip_local_port_range=1024 65535

# Configures socket buffers to support high-speed (10 Gbps) networks.
# rmem_max/wmem_max define the maximum receive/send buffer size (64 MB).
# rmem_default/wmem_default (208 KB) are optimized for typical connections, reducing latency.
net.core.rmem_max=67108864
net.core.wmem_max=67108864
net.core.rmem_default=212992
net.core.wmem_default=212992

# Enables TCP window scaling, allowing larger windows for high-speed networks.
# Essential to maximize throughput on 10 Gbps low-latency links.
net.ipv4.tcp_window_scaling=1

# Sets the default queueing discipline to 'fq' (Fair Queueing) for efficient packet management.
# Combined with the CUBIC congestion algorithm, it improves stability on local networks.
net.core.default_qdisc=fq
net.ipv4.tcp_congestion_control=cubic

# Enables Selective Acknowledgement (SACK) to confirm out-of-order packets.
# Reduces unnecessary retransmissions, improving efficiency on lossy networks.
net.ipv4.tcp_sack=1

# Sets the maximum size for TCP socket options (40 KB).
# Supports advanced options (e.g., timestamps, SACK) without overloading the kernel.
net.core.optmem_max=40960

# Configures TCP receive buffers (min, default, max).
# Minimum of 8192 bytes supports initial connections; maximum of 16 MB scales for 10 Gbps.
net.ipv4.tcp_rmem=8192 87380 16777216

# Configures TCP send buffers (min, default, max).
# Minimum of 8192 bytes avoids startup bottlenecks; maximum of 16 MB supports high load.
net.ipv4.tcp_wmem=8192 65536 16777216

# Increases the network interface packet backlog (5000) to handle traffic spikes.
# Reduces packet loss on 10 Gbps networks without overloading the kernel.
net.core.netdev_max_backlog=5000

# Sets the maximum number of pending SYN connections (8192).
# Supports high loads of simultaneous connections, as on web or proxy servers.
net.ipv4.tcp_max_syn_backlog=8192

# Increases the maximum number of TIME_WAIT sockets (2 million).
# Prevents socket exhaustion on servers with many short-lived connections.
net.ipv4.tcp_max_tw_buckets=2000000

# Allows reuse of TIME_WAIT sockets for new connections, reducing delays.
net.ipv4.tcp_tw_reuse=1

# Reduces how long FIN_WAIT sockets remain open (10 seconds).
# Frees resources quickly on high-turnover connection servers.
net.ipv4.tcp_fin_timeout=10

# Enables TCP slow start after idle periods to reduce retransmissions on unstable networks.
# Helps stabilize connections on high-speed local networks.
net.ipv4.tcp_slow_start_after_idle=1

# Increases minimum buffers for UDP (16 KB) to support high-load UDP applications.
# Useful for streaming or other UDP services on 10 Gbps networks.
net.ipv4.udp_rmem_min=16384
net.ipv4.udp_wmem_min=16384

# Disables logging of packets with invalid addresses (martians) to reduce unnecessary logs.
# Improves security and prevents overload on network servers.
net.ipv4.conf.all.log_martians=0

# Disables acceptance of source routes to avoid vulnerabilities on local networks.
# Unnecessary in modern setups and increases security.
net.ipv4.conf.all.accept_source_route=0

# Disables sending of ICMP redirects to prevent routing attacks.
# Safe for local networks where redirects aren’t used.
net.ipv4.conf.all.send_redirects=0

# Disables acceptance of ICMP redirects for greater security.
# Prevents malicious route manipulation on local networks.
net.ipv4.conf.all.accept_redirects=0

# Increases the maximum number of orphaned TCP sockets (262144).
# Supports servers with many connections without active clients (e.g., proxies).
net.ipv4.tcp_max_orphans=262144

# Enables MTU probing to dynamically adjust packet size.
# Avoids fragmentation on variable-MTU networks, reducing retransmissions.
net.ipv4.tcp_mtu_probing=1

# Enables TCP Fast Open (TFO) for faster connections.
# Value 3 enables TFO for both incoming and outgoing connections, ideal for web servers.
net.ipv4.tcp_fastopen=3

# Enables Forward RTO-Recovery (F-RTO) to improve loss recovery.
# Value 2 optimizes retransmissions on low-latency networks.
net.ipv4.tcp_frto=2

# Increases the number of packets processed per network interrupt (300).
# Improves packet handling on 10 Gbps networks, reducing losses.
net.core.netdev_budget=300

# Enables Early Retransmit to reduce retransmission latency.
# Value 3 optimizes lost packet recovery on local networks.
net.ipv4.tcp_early_retrans=3

# Prioritizes low latency over maximum throughput.
# Ideal for local networks with RTT of 1–5 ms, reducing retransmissions.
net.ipv4.tcp_low_latency=1

# Enables Explicit Congestion Notification (ECN) to prevent packet loss.
# Marks congestion before dropping packets, improving efficiency.
net.ipv4.tcp_ecn=1

vm.vfs_cache_pressure=200
vm.swappiness=10