sysctl.conf

# Disable IPv4 forwarding (default)
net.ipv4.ip_forward = 0

# Disable ICMP echo reply (if you need to reduce ping responses)
net.ipv4.icmp_echo_ignore_all = 1

# Enable TCP SYN cookies (security against SYN flood attacks)
net.ipv4.tcp_syncookies = 1

# Increase TCP buffer sizes for wireless and high throughput networks
net.ipv4.tcp_rmem = 8192  131072  67108864  # Set to 64MB max buffer size for high throughput
net.ipv4.tcp_wmem = 8192  131072  67108864  # Increased write buffer size for upload stability

# Enable TCP window scaling for higher throughput and bandwidth
net.ipv4.tcp_window_scaling = 1

# Increase maximum number of incoming connections for heavy network usage
net.core.somaxconn = 4096

# Increase maximum file descriptors for better handling of many files
fs.file-max = 2097152

# Optimize scheduling for real-time tasks (audio, video)
kernel.sched_rt_runtime_us = 950000
kernel.sched_rt_runtime_us = 2000000

# Increase the maximum number of memory map areas per process
vm.max_map_count = 524288  # Increased for applications using a lot of mmap

# Lower swappiness to prioritize RAM over swap
vm.swappiness = 10

# Adjust VFS cache pressure to avoid premature cache clearing
vm.vfs_cache_pressure = 50

# Optimize dirty memory settings for faster disk writes
vm.dirty_ratio = 15              # Higher limit for dirty pages in percentage
vm.dirty_background_ratio = 5    # Start flushing at a lower percentage

# Increase shared memory limits for high-performance apps (e.g., databases)
kernel.shmmax = 68719476736  # 64GB shared memory
kernel.shmall = 2097152      # Number of shared memory pages

# Adjust min_free_kbytes to improve memory handling under heavy load
vm.min_free_kbytes = 262144  # Set to 256MB to improve stability on high memory load

# Increase TCP connection backlog
net.ipv4.tcp_max_syn_backlog = 8192  # Handle more simultaneous connection requests

# Disable IPv6 (if not using it, as it may conflict with some networks)
net.ipv6.conf.all.disable_ipv6 = 1

# Enable high memory limits for processes
kernel.panic = 10

# Optimize VM overcommit handling
vm.overcommit_memory = 1       # Allow overcommit with heuristics to avoid OOM killer
vm.overcommit_ratio = 50       # Allow 50% of RAM for overcommitted allocations

# Decrease TCP timeout values to detect dead connections quicker
net.ipv4.tcp_fin_timeout = 15
net.ipv4.tcp_keepalive_time = 600     # Set keepalive to 10 minutes
net.ipv4.tcp_keepalive_intvl = 30     # Reduced interval for keepalive probes
net.ipv4.tcp_keepalive_probes = 5     # Number of probes before closing a connection

# Wireless optimizations for Mediatek MT7922
net.core.netdev_max_backlog = 10000   # Increase network backlog to handle bursts
net.core.rmem_max = 67108864          # Increase max receive buffer size (64MB)
net.core.wmem_max = 67108864          # Increase max send buffer size (64MB)

# Reduce TCP retransmission retries to improve latency and responsiveness
net.ipv4.tcp_retries2 = 8

# Disable slow start after idle to maintain maximum throughput on Wi-Fi
net.ipv4.tcp_slow_start_after_idle = 0

# Enable BBR (Bottleneck Bandwidth and RTT) congestion control for better performance on wireless
net.ipv4.tcp_congestion_control = bbr

# Set kernel network queue sizes to handle high throughput without packet loss
net.core.optmem_max = 25165824        # Increase optional memory for socket buffers (24MB)
net.ipv4.tcp_mem = 67108864 134217728 268435456  # Fine-tuned memory lisysctl: cannot stat /proc/sys/net/netfilter/nf_conntrack_max: No such file or directory
mits for TCP stack

# Disable Power Management for MT7922 to prevent Wi-Fi dropouts (use iwconfig or driver-specific methods)
# Adjust depending on your driver. If using `iwconfig`, run this separately after boot.
# sudo iwconfig wlan0 power off

# Set up IRQ balance for better multi-core CPU performance with networking
# Optional: You can add irqbalance service to optimize IRQ distribution across CPU cores
# sudo systemctl enable irqbalance

# Enable TCP Fast Open (TFO) for faster connection establishment
net.ipv4.tcp_fastopen = 3  # Enable TFO for both client and server