# Disable Explicit Congestion Notification in TCP
net.ipv4.tcp_ecn=0

# window scaling
net.ipv4.tcp_window_scaling=1

# Tuning dedicated memory to network cards
net.core.rmem_default = 1048576
net.core.wmem_default = 1048576

# UDP tuning
net.ipv4.udp_rmem_min = 8192
net.ipv4.udp_wmem_min = 8192

# increase linux autotuning tcp buffer limits
net.ipv4.tcp_rmem = 4096 1048576 2097152
net.ipv4.tcp_wmem = 4096 65536 16777216

# increase TCP max buffer size
net.core.rmem_max=16777216
net.core.wmem_max=16777216

# Increase number of incoming connections backlog
net.core.netdev_max_backlog=16384
net.core.dev_weight=64

# Increase number of incoming connections
# net.core.somaxconn=8096

# Increase the maximum amount of option memory buffers
net.core.optmem_max = 65536

# Increase the tcp-time-wait buckets pool size to prevent simple DOS attacks
net.ipv4.tcp_max_tw_buckets=1440000

# try to reuse time-wait connections, but don't recycle them (recycle can break clients behind NAT)
net.ipv4.tcp_tw_reuse=1

# Limit number of orphans, each orphan can eat up to 16M (max wmem) of unswappable memory
net.ipv4.tcp_max_orphans=16384
net.ipv4.tcp_orphan_retries=0

# don't cache ssthresh from previous connection
net.ipv4.tcp_no_metrics_save=1
net.ipv4.tcp_moderate_rcvbuf=1

# Increase size of RPC datagram queue length
net.unix.max_dgram_qlen=50

# Don't allow the arp table to become bigger than this
net.ipv4.neigh.default.gc_thresh3=2048

# Tell the gc when to become aggressive with arp table cleaning.
# Adjust this based on size of the LAN. 1024 is suitable for most /24 networks
net.ipv4.neigh.default.gc_thresh2=1024

# Adjust where the gc will leave arp table alone - set to 32.
net.ipv4.neigh.default.gc_thresh1=32

# Adjust to arp table gc to clean-up more often
net.ipv4.neigh.default.gc_interval=30

# Increase TCP queue length
net.ipv4.neigh.default.proxy_qlen=96
net.ipv4.neigh.default.unres_qlen=6

# Enable Explicit Congestion Notification (RFC 3168), disable it if it doesn't work for you
net.ipv4.tcp_ecn=1
net.ipv4.tcp_reordering=3

# How many times to retry killing an alive TCP connection
net.ipv4.tcp_retries2=15
net.ipv4.tcp_retries1=3

# Avoid falling back to slow start after a connection goes idle
# keeps our cwnd large with the keep alive connections (kernel > 3.6)
net.ipv4.tcp_slow_start_after_idle=0

# Allow the TCP fastopen flag to be used, beware some firewalls do not like TFO! (kernel > 3.7)
net.ipv4.tcp_fastopen=3

# This will enusre that immediatly subsequent connections use the new values
net.ipv4.route.flush=1
net.ipv6.route.flush=1

# Tune TCP keepalive parameters
net.ipv4.tcp_keepalive_time = 60
net.ipv4.tcp_keepalive_intvl = 10
net.ipv4.tcp_keepalive_probes = 6