webinoly/templates/general/sysctl
Cristhian Martínez Ochoa 953696330e kernel
new location for kernel config file (sysctl)
2022-11-21 14:26:29 -07:00

300 lines
9.2 KiB
Text

# Webinoly (This configuration file is only for internal use)
#####################################################################################################
# Please, DO NOT MODIFY this file, all the changes will be lost. #
# If you need to add/modify any of the existing rules, here: /etc/sysctl.conf #
# Please, read the documentation: https://webinoly.com/documentation/ #
#####################################################################################################
#######################################
### GENERAL SYSTEM SECURITY OPTIONS ###
#######################################
# Maximum number of files the kernel can be allocated
fs.file-max = 9223372036854775807
# Maximum number of files that can be assigned a single process
fs.nr_open = 2147483584
# Maximum number of asynchronous I/O requests
fs.aio-max-nr = 18446744073709551615
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1
#Allow for more PIDs
kernel.pid_max = 4194304
# Address space layout randomization (ASLR)
kernel.randomize_va_space = 2
# Controls the maximum size of a message, in bytes
kernel.sem = 32000 1024000000 500 32000
kernel.msgmni = 16384
kernel.msgmax = 65535
kernel.msgmnb = 65535
# Restrict core dumps
fs.suid_dumpable = 0
# Restrict access to kernel logs
kernel.dmesg_restrict = 1
# Hide exposed kernel pointers
kernel.kptr_restrict = 1
# Sets the time before the kernel considers migrating a proccess to another core
# This variable is no longer in sysctl, moved to: /sys/kernel/debug/sched/migration_cost_ns
#kernel.sched_migration_cost_ns = 5000000
# Group tasks by TTY
kernel.sched_autogroup_enabled = 0
########################################
### IMPROVE SYSTEM MEMORY MANAGEMENT ###
########################################
# Do less swapping
vm.swappiness = 10
vm.dirty_ratio = 50
vm.dirty_background_ratio = 5
vm.dirty_expire_centisecs = 1400
# Only for ram > 28G
#vm.dirty_bytes = 5505024000
#vm.dirty_background_bytes = 917504000
#vm.dirty_writeback_centisecs = 100
# specifies the minimum virtual address that a process is allowed to mmap
vm.mmap_min_addr = 65535
# 50% overcommitment of available memory
vm.overcommit_ratio = 50
vm.overcommit_memory = 0
# Set maximum amount of memory allocated to shm
kernel.shmall = 4294967296
kernel.shmmax = 68719476736
kernel.shmmni = 4096
# Keep at least 64MB of free RAM space available
vm.min_free_kbytes = 65535
# Vitual memory
vm.max_map_count = 262144
# Disable reclaim memory when a zone runs out of memory.
vm.zone_reclaim_mode = 0
########################################
### GENERAL NETWORK SECURITY OPTIONS ###
########################################
#Prevent SYN attack, enable SYNcookies (they will kick-in when the max_syn_backlog reached)
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 65535
# Never decrease these 'retries' values
net.ipv4.tcp_syn_retries = 6
net.ipv4.tcp_synack_retries = 5
# Disables packet forwarding
net.ipv4.ip_forward = 0
net.ipv4.conf.all.forwarding = 0
#net.ipv4.conf.all.mc_forwarding = 0
net.ipv4.conf.default.forwarding = 0
net.ipv6.conf.all.forwarding = 0
#net.ipv6.conf.all.mc_forwarding = 0
net.ipv6.conf.default.forwarding = 0
# Disables IP source routing
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0
net.ipv6.conf.all.accept_source_route = 0
net.ipv6.conf.default.accept_source_route = 0
# Disable ICMP Redirect Acceptance
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.all.secure_redirects = 0
net.ipv4.conf.default.secure_redirects = 0
net.ipv6.conf.all.accept_redirects = 0
net.ipv6.conf.default.accept_redirects = 0
# Deny Router Solicitations
net.ipv6.conf.all.router_solicitations = 0
net.ipv6.conf.default.router_solicitations = 0
net.ipv6.conf.all.accept_ra_rtr_pref = 0
net.ipv6.conf.default.accept_ra_rtr_pref = 0
net.ipv6.conf.all.accept_ra_pinfo = 0
net.ipv6.conf.default.accept_ra_pinfo = 0
net.ipv6.conf.all.accept_ra_defrtr = 0
net.ipv6.conf.default.accept_ra_defrtr = 0
net.ipv6.conf.all.dad_transmits = 0
net.ipv6.conf.default.dad_transmits = 0
# Enable IP spoofing protection, turn on source route verification
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1
# Enable Log Spoofed Packets, Source Routed Packets, Redirect Packets
net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.default.log_martians = 1
# Decrease the time default value for tcp_fin_timeout connection
net.ipv4.tcp_fin_timeout = 7
# Decrease the time default value for connections to keep alive
net.ipv4.tcp_keepalive_time = 90
net.ipv4.tcp_keepalive_intvl = 10
net.ipv4.tcp_keepalive_probes = 9
# Don't relay bootp
net.ipv4.conf.all.bootp_relay = 0
# Don't proxy arp for anyone
net.ipv4.conf.all.proxy_arp = 0
# Turn on the tcp_timestamps, accurate timestamp make TCP congestion control algorithms work better
net.ipv4.tcp_timestamps = 1
# Don't ignore directed pings
net.ipv4.icmp_echo_ignore_all = 0
# Enable ignoring broadcasts request
net.ipv4.icmp_echo_ignore_broadcasts = 1
# Enable bad error message Protection
net.ipv4.icmp_ignore_bogus_error_responses = 1
# Allowed local port range
net.ipv4.ip_local_port_range = 1024 65535
# Enable a fix for RFC1337 - time-wait assassination hazards in TCP
net.ipv4.tcp_rfc1337 = 1
net.ipv4.tcp_sack=1
net.ipv4.tcp_mtu_probing = 1
net.ipv4.tcp_base_mss = 1024
# Workaround for the RFC 5961 Linux TCP flaw?
net.ipv4.tcp_challenge_ack_limit = 999999999
# Restrict IPv6 Maximum Addresses
net.ipv6.conf.all.max_addresses = 1
net.ipv6.conf.default.max_addresses = 1
##################################
### TUNING NETWORK PERFORMANCE ###
##################################
# For high-bandwidth low-latency networks, use 'bbr' congestion control (kernel > 4.9)
# Only enabled in bionic (at least v4.15)
# Do a 'sudo modprobe tcp_bbr' first
net.ipv4.tcp_congestion_control = bbr
net.ipv4.tcp_notsent_lowat = 16384
# Enable 'fq' queue management scheduler (kernel > 3.12)
net.core.default_qdisc = fq
# Turn on the tcp_window_scaling
net.ipv4.tcp_window_scaling = 1
# Disabled (we have seen performance decreased when enabled)
net.core.busy_read = 0
net.core.busy_poll = 0
# Maximum number of packets taken from all interfaces in one polling cycle (NAPI poll).
net.core.netdev_budget = 425
# Seems like defaults are better for performance!
# Increase the read-buffer space allocatable
#net.ipv4.tcp_rmem = 4096 131072 6291456
#net.ipv4.udp_rmem_min = 4096
#net.core.rmem_default = 212992
#net.core.rmem_max = 212992
# Increase the write-buffer-space allocatable
#net.ipv4.tcp_wmem = 4096 16384 4194304
#net.ipv4.udp_wmem_min = 4096
#net.core.wmem_default = 212992
#net.core.wmem_max = 212992
# Increase number of incoming connections
net.core.somaxconn = 65535
# Increase number of incoming connections backlog
net.core.netdev_max_backlog = 16384
net.core.dev_weight = 64
# Increase the maximum amount of option memory buffers
net.core.optmem_max = 65535
# When mem allocated by TCP exceeds “pressure”, kernel will put pressure on TCP memory
net.ipv4.tcp_mem=8388608 8388608 8388608
# Increase the tcp-time-wait buckets pool size to prevent simple DOS attacks
net.ipv4.tcp_max_tw_buckets = 450000
# try to reuse time-wait connections, (recycle is deprecated)
#net.ipv4.tcp_tw_recycle = 0
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 = 262144
net.ipv4.tcp_orphan_retries = 0
# Limit the maximum memory used to reassemble IP fragments (CVE-2018-5391)
net.ipv4.ipfrag_low_thresh = 196608
net.ipv6.ip6frag_low_thresh = 196608
net.ipv4.ipfrag_high_thresh = 262144
net.ipv6.ip6frag_high_thresh = 262144
# 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 = 512
# Prevent ARP issues
net.ipv4.neigh.default.gc_thresh1 = 30000
net.ipv4.neigh.default.gc_thresh2 = 32000
net.ipv4.neigh.default.gc_thresh3 = 32768
net.ipv6.neigh.default.gc_thresh1 = 30000
net.ipv6.neigh.default.gc_thresh2 = 32000
net.ipv6.neigh.default.gc_thresh3 = 32768
# 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