267 lines
7.9 KiB
Plaintext
267 lines
7.9 KiB
Plaintext
# Kernel sysctl configuration file for Linux
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#
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# Version 1.16 - 2018-10-23
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# Michiel Klaver - IT Professional
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# Modified by VirtuBox
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#
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# Instructions available on https://github.com/VirtuBox/ubuntu-nginx-web-server
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#
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# Sources :
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# https://klaver.it/linux/sysctl.conf
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# https://easyengine.io/tutorials/linux/sysctl-conf/
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#
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#
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# Credits:
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#
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# http://www.enigma.id.au/linux_tuning.txt
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# http://www.securityfocus.com/infocus/1729
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# http://fasterdata.es.net/TCP-tuning/linux.html
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# http://fedorahosted.org/ktune/browser/sysctl.ktune
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# http://www.cymru.com/Documents/ip-stack-tuning.html
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# http://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt
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# http://www.frozentux.net/ipsysctl-tutorial/chunkyhtml/index.html
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# http://knol.google.com/k/linux-performance-tuning-and-measurement
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# http://www.cyberciti.biz/faq/linux-kernel-tuning-virtual-memory-subsystem/
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# http://www.redbooks.ibm.com/abstracts/REDP4285.html
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# http://www.speedguide.net/read_articles.php?id=121
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# http://lartc.org/howto/lartc.kernel.obscure.html
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# http://en.wikipedia.org/wiki/Sysctl
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#
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# Usage
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# wget -O /etc/sysctl.d/60-ubuntu-nginx-web-server.conf https://virtubox.github.io/ubuntu-nginx-web-server/files/etc/sysctl.d/60-ubuntu-nginx-web-server.conf
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#
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# sysctl -e -p /etc/sysctl.d/60-ubuntu-nginx-web-server.conf
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# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and sysctl.conf(5) for more details.
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#
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###
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### GENERAL SYSTEM SECURITY OPTIONS ###
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###
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# Controls the System Request debugging functionality of the kernel
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kernel.sysrq = 0
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# Controls whether core dumps will append the PID to the core filename.
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# Useful for debugging multi-threaded applications.
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kernel.core_uses_pid = 1
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#Allow for more PIDs
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kernel.pid_max = 65535
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# The contents of /proc/<pid>/maps and smaps files are only visible to
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# readers that are allowed to ptrace() the process
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kernel.maps_protect = 1
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#Enable ExecShield protection
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kernel.exec-shield = 1
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kernel.randomize_va_space = 2
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# Controls the maximum size of a message, in bytes
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kernel.msgmnb = 65535
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# Controls the default maxmimum size of a mesage queue
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kernel.msgmax = 65535
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# Restrict core dumps
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fs.suid_dumpable = 0
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# Hide exposed kernel pointers
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kernel.kptr_restrict = 1
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###
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### IMPROVE SYSTEM MEMORY MANAGEMENT ###
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###
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# Increase size of file handles and inode cache
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fs.file-max = 209708
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# Do less swapping
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vm.swappiness = 10
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vm.dirty_ratio = 30
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vm.dirty_background_ratio = 5
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# specifies the minimum virtual address that a process is allowed to mmap
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vm.mmap_min_addr = 4096
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# 50% overcommitment of available memory
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vm.overcommit_ratio = 50
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# allow memory overcommit required for redis
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vm.overcommit_memory = 1
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# Set maximum amount of memory allocated to shm to 256MB
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kernel.shmmax = 268435456
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kernel.shmall = 268435456
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# Keep at least 64MB of free RAM space available
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vm.min_free_kbytes = 65535
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###
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### GENERAL NETWORK SECURITY OPTIONS ###
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###
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#Prevent SYN attack, enable SYNcookies (they will kick-in when the max_syn_backlog reached)
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net.ipv4.tcp_syncookies = 1
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net.ipv4.tcp_syn_retries = 2
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net.ipv4.tcp_synack_retries = 2
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net.ipv4.tcp_max_syn_backlog = 4096
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# Disables IP source routing
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net.ipv4.conf.all.send_redirects = 0
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net.ipv4.conf.default.send_redirects = 0
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net.ipv4.conf.all.accept_source_route = 0
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net.ipv4.conf.default.accept_source_route = 0
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net.ipv6.conf.all.accept_source_route = 0
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net.ipv6.conf.default.accept_source_route = 0
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# Enable IP spoofing protection, turn on source route verification
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net.ipv4.conf.all.rp_filter = 1
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net.ipv4.conf.default.rp_filter = 1
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# Disable ICMP Redirect Acceptance
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net.ipv4.conf.all.accept_redirects = 0
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net.ipv4.conf.default.accept_redirects = 0
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net.ipv4.conf.all.secure_redirects = 0
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net.ipv4.conf.default.secure_redirects = 0
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net.ipv6.conf.all.accept_redirects = 0
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net.ipv6.conf.default.accept_redirects = 0
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# Enable Log Spoofed Packets, Source Routed Packets, Redirect Packets
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net.ipv4.conf.all.log_martians = 1
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net.ipv4.conf.default.log_martians = 1
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# Decrease the time default value for tcp_fin_timeout connection
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net.ipv4.tcp_fin_timeout = 7
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# Decrease the time default value for connections to keep alive
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net.ipv4.tcp_keepalive_time = 300
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net.ipv4.tcp_keepalive_probes = 5
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net.ipv4.tcp_keepalive_intvl = 15
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# Don't relay bootp
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net.ipv4.conf.all.bootp_relay = 0
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# Don't proxy arp for anyone
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net.ipv4.conf.all.proxy_arp = 0
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# Turn on the tcp_timestamps, accurate timestamp make TCP congestion control algorithms work better
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net.ipv4.tcp_timestamps = 1
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# Don't ignore directed pings
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net.ipv4.icmp_echo_ignore_all = 0
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# Enable ignoring broadcasts request
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net.ipv4.icmp_echo_ignore_broadcasts = 1
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# Enable bad error message Protection
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net.ipv4.icmp_ignore_bogus_error_responses = 1
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# Allowed local port range
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net.ipv4.ip_local_port_range = 16384 65535
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# Enable a fix for RFC1337 - time-wait assassination hazards in TCP
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net.ipv4.tcp_rfc1337 = 1
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# Do not auto-configure IPv6
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net.ipv6.conf.all.autoconf=0
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net.ipv6.conf.all.accept_ra=0
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net.ipv6.conf.default.autoconf=0
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net.ipv6.conf.default.accept_ra=0
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net.ipv6.conf.all.accept_ra_defrtr = 0
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net.ipv6.conf.default.accept_ra_defrtr = 0
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net.ipv6.conf.all.accept_ra_pinfo = 0
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net.ipv6.conf.default.accept_ra_pinfo = 0
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###
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### TUNING NETWORK PERFORMANCE ###
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###
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# For servers with tcp-heavy workloads, enable 'fq' queue management scheduler (kernel > 3.12)
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net.core.default_qdisc = fq
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# Turn on the tcp_window_scaling
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net.ipv4.tcp_window_scaling = 1
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# Increase the read-buffer space allocatable
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net.ipv4.tcp_rmem = 8192 87380 16777216
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net.ipv4.udp_rmem_min = 16384
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net.core.rmem_default = 262144
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net.core.rmem_max = 16777216
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# Increase the write-buffer-space allocatable
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net.ipv4.tcp_wmem = 8192 65536 16777216
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net.ipv4.udp_wmem_min = 16384
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net.core.wmem_default = 262144
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net.core.wmem_max = 16777216
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# Increase number of incoming connections
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net.core.somaxconn = 32768
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# Increase number of incoming connections backlog
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net.core.netdev_max_backlog = 16384
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net.core.dev_weight = 64
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# Increase the maximum amount of option memory buffers
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net.core.optmem_max = 65535
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# Increase the tcp-time-wait buckets pool size to prevent simple DOS attacks
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net.ipv4.tcp_max_tw_buckets = 1440000
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# try to reuse time-wait connections, but don't recycle them (recycle can break clients behind NAT)
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net.ipv4.tcp_tw_recycle = 0
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net.ipv4.tcp_tw_reuse = 1
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# Limit number of orphans, each orphan can eat up to 16M (max wmem) of unswappable memory
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net.ipv4.tcp_max_orphans = 16384
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net.ipv4.tcp_orphan_retries = 0
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# Limit the maximum memory used to reassemble IP fragments (CVE-2018-5391)
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net.ipv4.ipfrag_low_thresh = 196608
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net.ipv6.ip6frag_low_thresh = 196608
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net.ipv4.ipfrag_high_thresh = 262144
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net.ipv6.ip6frag_high_thresh = 262144
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# don't cache ssthresh from previous connection
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net.ipv4.tcp_no_metrics_save = 1
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net.ipv4.tcp_moderate_rcvbuf = 1
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# Increase size of RPC datagram queue length
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net.unix.max_dgram_qlen = 50
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# Don't allow the arp table to become bigger than this
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net.ipv4.neigh.default.gc_thresh3 = 2048
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# Tell the gc when to become aggressive with arp table cleaning.
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# Adjust this based on size of the LAN. 1024 is suitable for most /24 networks
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net.ipv4.neigh.default.gc_thresh2 = 1024
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# Adjust where the gc will leave arp table alone - set to 32.
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net.ipv4.neigh.default.gc_thresh1 = 32
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# Adjust to arp table gc to clean-up more often
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net.ipv4.neigh.default.gc_interval = 30
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# Increase TCP queue length
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net.ipv4.neigh.default.proxy_qlen = 96
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net.ipv4.neigh.default.unres_qlen = 6
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# Enable Explicit Congestion Notification (RFC 3168), disable it if it doesn't work for you
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net.ipv4.tcp_ecn = 1
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net.ipv4.tcp_reordering = 3
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# How many times to retry killing an alive TCP connection
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net.ipv4.tcp_retries2 = 15
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net.ipv4.tcp_retries1 = 3
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# Avoid falling back to slow start after a connection goes idle
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# keeps our cwnd large with the keep alive connections (kernel > 3.6)
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net.ipv4.tcp_slow_start_after_idle = 0
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# Allow the TCP fastopen flag to be used, beware some firewalls do not like TFO! (kernel > 3.7)
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net.ipv4.tcp_fastopen = 3
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# This will enusre that immediatly subsequent connections use the new values
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net.ipv4.route.flush = 1
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net.ipv6.route.flush = 1
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