すべてのカーネルパラメータの設定値を表示する。

sysctl -a
sysctl -A
でも同じ。

[root@localhost CentOS6 ~]#man sysctl
SYSCTL(8)                                                            SYSCTL(8)

NAME
       sysctl - configure kernel parameters at runtime

SYNOPSIS
       sysctl [-n] [-e] variable ...
       sysctl [-n] [-e] [-q] -w variable=value ...
       sysctl [-n] [-e] [-q] -p [filename]...
       sysctl [-n] [-e] [-q] --system
       sysctl [-n] [-e] -a
       sysctl [-n] [-e] -A

DESCRIPTION
       sysctl is used to modify kernel parameters at runtime.  The parameters available are those listed under /proc/sys/.  Procfs is required for sysctl(8) support in Linux.  You can use sysctl(8) to both read and write sysctl data.

PARAMETERS
       variable
              The name of a key to read from.  An example is kernel.ostype.  The ’/’ separator is also accepted in place of a ’.’.

       variable=value
              To set a key, use the form variable=value, where variable is the key and value is the value to set it to.  If the value contains quotes or characters which are parsed by the shell, you may need to enclose the value in double quotes.  This
              requires the -w parameter to use.

       -n     Use this option to disable printing of the key name when printing values.

       -e     Use this option to ignore errors about unknown keys.

       -N     Use this option to only print the names. It may be useful with shells that have programmable completion.

       -q     Use this option to not display the values set to stdout.

       -w     Use this option when you want to change a sysctl setting.

       -p     Load in sysctl settings from the file(s) specified or /etc/sysctl.conf if none given.  Specifying - as filename means reading data from standard input.

       --system
              Load settings from all system configuration files.
              /run/sysctl.d/*.conf
              /etc/sysctl.d/*.conf
              /usr/local/lib/sysctl.d/*.conf
              /usr/lib/sysctl.d/*.conf
              /lib/sysctl.d/*.conf
              /etc/sysctl.conf

       -a     Display all values currently available.

       -A     Same as -a

EXAMPLES
       /sbin/sysctl -a

       /sbin/sysctl -n kernel.hostname

       /sbin/sysctl -w kernel.domainname="example.com"

       /sbin/sysctl -p /etc/sysctl.conf

NOTES
       Please note that modules loaded after sysctl is run may override the settings (example: sunrpc.* settings are overridden when the sunrpc module is loaded). This may cause some confusion during boot when the settings in sysctl.conf may be overri-
       den. To prevent such a situation, sysctl must be run after the particular module is loaded (e.g., from /etc/rc.d/rc.local or by using the install directive in modprobe.conf)

FILES
       /proc/sys /etc/sysctl.conf

SEE ALSO
       sysctl.conf(5), modprobe.conf(5)

AUTHOR
       George Staikos, 

                                  21 Sep 1999                        SYSCTL(8)
@0wned.org>

CentOS6 での実行例

[root@localhost CentOS6 ~]#sysctl -a
kernel.sched_child_runs_first = 0
kernel.sched_min_granularity_ns = 2000000
kernel.sched_latency_ns = 10000000
kernel.sched_wakeup_granularity_ns = 2000000
kernel.sched_tunable_scaling = 1
kernel.sched_features = 7279
kernel.sched_migration_cost = 500000
kernel.sched_nr_migrate = 32
kernel.sched_time_avg = 1000
kernel.sched_shares_window = 10000000
kernel.timer_migration = 1
kernel.sched_rt_period_us = 1000000
kernel.sched_rt_runtime_us = 950000
kernel.sched_compat_yield = 0
kernel.sched_rr_timeslice_ms = 100
kernel.sched_autogroup_enabled = 0
kernel.sched_cfs_bandwidth_slice_us = 5000
kernel.panic = 0
kernel.exec-shield = 1
kernel.core_uses_pid = 1
kernel.core_pattern = core
kernel.core_pipe_limit = 0
kernel.tainted = 0
kernel.real-root-dev = 0
kernel.print-fatal-signals = 0
kernel.ctrl-alt-del = 0
kernel.ftrace_dump_on_oops = 0
kernel.modprobe = /sbin/modprobe
kernel.modules_disabled = 0
kernel.kexec_load_disabled = 0
kernel.hotplug = 
kernel.acct = 4	2	30
kernel.sysrq = 0
kernel.cad_pid = 1
kernel.threads-max = 29839
kernel.random.poolsize = 4096
kernel.random.entropy_avail = 216
kernel.random.read_wakeup_threshold = 64
kernel.random.write_wakeup_threshold = 128
kernel.random.boot_id = 87f69358-24bb-432f-bfbd-ea5b49e48825
kernel.random.uuid = e1f780ad-f051-45e2-87dd-86c7f98ca28c
kernel.usermodehelper.bset = 4294967295	4294967295
kernel.usermodehelper.inheritable = 4294967295	4294967295
kernel.overflowuid = 65534
kernel.overflowgid = 65534
kernel.pid_max = 32768
kernel.panic_on_oops = 1
kernel.printk = 4	4	1	7
kernel.printk_ratelimit = 5
kernel.printk_ratelimit_burst = 10
kernel.printk_delay = 0
kernel.dmesg_restrict = 0
kernel.kptr_restrict = 1
kernel.ngroups_max = 65536
kernel.cap_last_cap = 33
kernel.watchdog = 1
kernel.watchdog_thresh = 60
kernel.softlockup_panic = 0
kernel.hardlockup_panic = 1
kernel.softlockup_all_cpu_backtrace = 0
kernel.hardlockup_all_cpu_backtrace = 0
kernel.nmi_watchdog = 1
kernel.unknown_nmi_panic = 0
kernel.panic_on_unrecovered_nmi = 0
kernel.panic_on_io_nmi = 0
kernel.bootloader_type = 113
kernel.bootloader_version = 1
kernel.kstack_depth_to_print = 24
kernel.io_delay_type = 0
kernel.randomize_va_space = 2
kernel.acpi_video_flags = 0
kernel.hung_task_panic = 0
kernel.hung_task_check_count = 32768
kernel.hung_task_timeout_secs = 120
kernel.hung_task_warnings = 10
kernel.max_lock_depth = 1024
kernel.poweroff_cmd = /sbin/poweroff
kernel.keys.maxkeys = 200
kernel.keys.maxbytes = 20000
kernel.keys.root_maxkeys = 1000000
kernel.keys.root_maxbytes = 25000000
kernel.keys.gc_delay = 300
kernel.slow-work.min-threads = 2
kernel.slow-work.max-threads = 4
kernel.slow-work.vslow-percentage = 50
kernel.perf_event_paranoid = 1
kernel.perf_event_mlock_kb = 516
kernel.perf_event_max_sample_rate = 100000
kernel.blk_iopoll = 1
kernel.panic_on_warn = 0
kernel.sched_domain.cpu0.domain0.min_interval = 1
kernel.sched_domain.cpu0.domain0.max_interval = 2
kernel.sched_domain.cpu0.domain0.busy_idx = 0
kernel.sched_domain.cpu0.domain0.idle_idx = 0
kernel.sched_domain.cpu0.domain0.newidle_idx = 0
kernel.sched_domain.cpu0.domain0.wake_idx = 0
kernel.sched_domain.cpu0.domain0.forkexec_idx = 0
kernel.sched_domain.cpu0.domain0.busy_factor = 64
kernel.sched_domain.cpu0.domain0.imbalance_pct = 110
kernel.sched_domain.cpu0.domain0.cache_nice_tries = 0
kernel.sched_domain.cpu0.domain0.flags = 687
kernel.sched_domain.cpu0.domain0.name = SIBLING
kernel.sched_domain.cpu0.domain1.min_interval = 1
kernel.sched_domain.cpu0.domain1.max_interval = 4
kernel.sched_domain.cpu0.domain1.busy_idx = 2
kernel.sched_domain.cpu0.domain1.idle_idx = 0
kernel.sched_domain.cpu0.domain1.newidle_idx = 0
kernel.sched_domain.cpu0.domain1.wake_idx = 0
kernel.sched_domain.cpu0.domain1.forkexec_idx = 0
kernel.sched_domain.cpu0.domain1.busy_factor = 64
kernel.sched_domain.cpu0.domain1.imbalance_pct = 125
kernel.sched_domain.cpu0.domain1.cache_nice_tries = 1
kernel.sched_domain.cpu0.domain1.flags = 4655
kernel.sched_domain.cpu0.domain1.name = MC
kernel.sched_domain.cpu1.domain0.min_interval = 1
kernel.sched_domain.cpu1.domain0.max_interval = 2
kernel.sched_domain.cpu1.domain0.busy_idx = 0
kernel.sched_domain.cpu1.domain0.idle_idx = 0
kernel.sched_domain.cpu1.domain0.newidle_idx = 0
kernel.sched_domain.cpu1.domain0.wake_idx = 0
kernel.sched_domain.cpu1.domain0.forkexec_idx = 0
kernel.sched_domain.cpu1.domain0.busy_factor = 64
kernel.sched_domain.cpu1.domain0.imbalance_pct = 110
kernel.sched_domain.cpu1.domain0.cache_nice_tries = 0
kernel.sched_domain.cpu1.domain0.flags = 687
kernel.sched_domain.cpu1.domain0.name = SIBLING
kernel.sched_domain.cpu1.domain1.min_interval = 1
kernel.sched_domain.cpu1.domain1.max_interval = 4
kernel.sched_domain.cpu1.domain1.busy_idx = 2
kernel.sched_domain.cpu1.domain1.idle_idx = 0
kernel.sched_domain.cpu1.domain1.newidle_idx = 0
kernel.sched_domain.cpu1.domain1.wake_idx = 0
kernel.sched_domain.cpu1.domain1.forkexec_idx = 0
kernel.sched_domain.cpu1.domain1.busy_factor = 64
kernel.sched_domain.cpu1.domain1.imbalance_pct = 125
kernel.sched_domain.cpu1.domain1.cache_nice_tries = 1
kernel.sched_domain.cpu1.domain1.flags = 4655
kernel.sched_domain.cpu1.domain1.name = MC
kernel.ostype = Linux
kernel.osrelease = 2.6.32-642.3.1.el6.i686
kernel.version = #1 SMP Tue Jul 12 17:53:37 UTC 2016
kernel.hostname = localhost.localdomain
kernel.domainname = (none)
kernel.pty.max = 4096
kernel.pty.nr = 1
kernel.shmmax = 4294967295
kernel.shmall = 268435456
kernel.shmmni = 4096
kernel.shm_rmid_forced = 0
kernel.msgmax = 65536
kernel.msgmni = 1457
kernel.msgmnb = 65536
kernel.sem = 250	32000	32	128
kernel.auto_msgmni = 1
vm.overcommit_memory = 0
vm.panic_on_oom = 0
vm.oom_kill_allocating_task = 0
vm.extfrag_threshold = 500
vm.oom_dump_tasks = 1
vm.would_have_oomkilled = 0
vm.overcommit_ratio = 50
vm.overcommit_kbytes = 0
vm.page-cluster = 3
vm.dirty_background_ratio = 10
vm.dirty_background_bytes = 0
vm.dirty_ratio = 20
vm.dirty_bytes = 0
vm.dirty_writeback_centisecs = 500
vm.dirty_expire_centisecs = 3000
vm.nr_pdflush_threads = 0
vm.swappiness = 60
vm.nr_hugepages = 0
vm.hugetlb_shm_group = 0
vm.hugepages_treat_as_movable = 0
vm.nr_overcommit_hugepages = 0
vm.lowmem_reserve_ratio = 256	32	32
vm.drop_caches = 0
vm.min_free_kbytes = 3794
vm.extra_free_kbytes = 0
vm.unmap_area_factor = 0
vm.meminfo_legacy_layout = 1
vm.percpu_pagelist_fraction = 0
vm.max_map_count = 65530
vm.laptop_mode = 0
vm.block_dump = 0
vm.vfs_cache_pressure = 100
vm.legacy_va_layout = 0
vm.stat_interval = 1
vm.mmap_min_addr = 4096
vm.vdso_enabled = 1
vm.highmem_is_dirtyable = 0
vm.scan_unevictable_pages = 0
vm.admin_reserve_kbytes = 8192
fs.inode-nr = 13546	224
fs.inode-state = 13546	224	0	0	0	0	0
fs.file-nr = 640	0	190190
fs.file-max = 190190
fs.nr_open = 1048576
fs.dentry-state = 14375	6701	45	0	0	0
fs.overflowuid = 65534
fs.overflowgid = 65534
fs.leases-enable = 1
fs.dir-notify-enable = 1
fs.lease-break-time = 45
fs.aio-nr = 0
fs.aio-max-nr = 65536
fs.inotify.max_user_instances = 128
fs.inotify.max_user_watches = 8192
fs.inotify.max_queued_events = 16384
fs.epoll.max_user_watches = 276631
fs.suid_dumpable = 0
fs.binfmt_misc.status = enabled
fs.quota.lookups = 0
fs.quota.drops = 0
fs.quota.reads = 0
fs.quota.writes = 0
fs.quota.cache_hits = 0
fs.quota.allocated_dquots = 0
fs.quota.free_dquots = 0
fs.quota.syncs = 0
fs.quota.warnings = 1
fs.mqueue.queues_max = 256
fs.mqueue.msg_max = 10
fs.mqueue.msgsize_max = 8192
fs.mqueue.msg_default = 10
fs.mqueue.msgsize_default = 8192
debug.exception-trace = 1
debug.kprobes-optimization = 1
dev.scsi.logging_level = 0
dev.raid.speed_limit_min = 1000
dev.raid.speed_limit_max = 200000
dev.hpet.max-user-freq = 64
dev.mac_hid.mouse_button_emulation = 0
dev.mac_hid.mouse_button2_keycode = 97
dev.mac_hid.mouse_button3_keycode = 100
net.netfilter.nf_log.0 = NONE
net.netfilter.nf_log.1 = NONE
net.netfilter.nf_log.2 = NONE
net.netfilter.nf_log.3 = NONE
net.netfilter.nf_log.4 = NONE
net.netfilter.nf_log.5 = NONE
net.netfilter.nf_log.6 = NONE
net.netfilter.nf_log.7 = NONE
net.netfilter.nf_log.8 = NONE
net.netfilter.nf_log.9 = NONE
net.netfilter.nf_log.10 = NONE
net.netfilter.nf_log.11 = NONE
net.netfilter.nf_log.12 = NONE
net.netfilter.nf_conntrack_generic_timeout = 600
net.netfilter.nf_conntrack_tcp_timeout_syn_sent = 120
net.netfilter.nf_conntrack_tcp_timeout_syn_recv = 60
net.netfilter.nf_conntrack_tcp_timeout_established = 432000
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60
net.netfilter.nf_conntrack_tcp_timeout_last_ack = 30
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close = 10
net.netfilter.nf_conntrack_tcp_timeout_max_retrans = 300
net.netfilter.nf_conntrack_tcp_timeout_unacknowledged = 300
net.netfilter.nf_conntrack_tcp_loose = 1
net.netfilter.nf_conntrack_tcp_be_liberal = 0
net.netfilter.nf_conntrack_tcp_max_retrans = 3
net.netfilter.nf_conntrack_udp_timeout = 30
net.netfilter.nf_conntrack_udp_timeout_stream = 180
net.netfilter.nf_conntrack_icmpv6_timeout = 30
net.netfilter.nf_conntrack_icmp_timeout = 30
net.netfilter.nf_conntrack_acct = 0
net.netfilter.nf_conntrack_events = 1
net.netfilter.nf_conntrack_events_retry_timeout = 15
net.netfilter.nf_conntrack_max = 65536
net.netfilter.nf_conntrack_count = 2
net.netfilter.nf_conntrack_buckets = 16384
net.netfilter.nf_conntrack_checksum = 1
net.netfilter.nf_conntrack_log_invalid = 0
net.netfilter.nf_conntrack_expect_max = 256
net.core.somaxconn = 128
net.core.xfrm_aevent_etime = 10
net.core.xfrm_aevent_rseqth = 2
net.core.xfrm_larval_drop = 1
net.core.xfrm_acq_expires = 30
net.core.wmem_max = 112640
net.core.rmem_max = 112640
net.core.wmem_default = 112640
net.core.rmem_default = 112640
net.core.dev_weight = 64
net.core.netdev_max_backlog = 1000
net.core.netdev_rss_key = 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
net.core.message_cost = 5
net.core.message_burst = 10
net.core.optmem_max = 10240
net.core.rps_sock_flow_entries = 0
net.core.busy_poll = 0
net.core.busy_read = 0
net.core.default_qdisc = pfifo_fast
net.core.netdev_budget = 300
net.core.warnings = 1
net.ipv4.route.gc_thresh = 32768
net.ipv4.route.max_size = 524288
net.ipv4.route.gc_min_interval = 0
net.ipv4.route.gc_min_interval_ms = 500
net.ipv4.route.gc_timeout = 300
net.ipv4.route.gc_interval = 60
net.ipv4.route.redirect_load = 20
net.ipv4.route.redirect_number = 9
net.ipv4.route.redirect_silence = 20480
net.ipv4.route.error_cost = 1000
net.ipv4.route.error_burst = 5000
net.ipv4.route.gc_elasticity = 8
net.ipv4.route.mtu_expires = 600
net.ipv4.route.min_pmtu = 552
net.ipv4.route.min_adv_mss = 256
net.ipv4.route.secret_interval = 600
net.ipv4.neigh.default.mcast_solicit = 3
net.ipv4.neigh.default.ucast_solicit = 3
net.ipv4.neigh.default.app_solicit = 0
net.ipv4.neigh.default.retrans_time = 99
net.ipv4.neigh.default.base_reachable_time = 30
net.ipv4.neigh.default.delay_first_probe_time = 5
net.ipv4.neigh.default.gc_stale_time = 60
net.ipv4.neigh.default.unres_qlen = 3
net.ipv4.neigh.default.proxy_qlen = 64
net.ipv4.neigh.default.anycast_delay = 99
net.ipv4.neigh.default.proxy_delay = 79
net.ipv4.neigh.default.locktime = 99
net.ipv4.neigh.default.retrans_time_ms = 1000
net.ipv4.neigh.default.base_reachable_time_ms = 30000
net.ipv4.neigh.default.gc_interval = 30
net.ipv4.neigh.default.gc_thresh1 = 128
net.ipv4.neigh.default.gc_thresh2 = 512
net.ipv4.neigh.default.gc_thresh3 = 1024
net.ipv4.neigh.lo.mcast_solicit = 3
net.ipv4.neigh.lo.ucast_solicit = 3
net.ipv4.neigh.lo.app_solicit = 0
net.ipv4.neigh.lo.retrans_time = 99
net.ipv4.neigh.lo.base_reachable_time = 30
net.ipv4.neigh.lo.delay_first_probe_time = 5
net.ipv4.neigh.lo.gc_stale_time = 60
net.ipv4.neigh.lo.unres_qlen = 3
net.ipv4.neigh.lo.proxy_qlen = 64
net.ipv4.neigh.lo.anycast_delay = 99
net.ipv4.neigh.lo.proxy_delay = 79
net.ipv4.neigh.lo.locktime = 99
net.ipv4.neigh.lo.retrans_time_ms = 1000
net.ipv4.neigh.lo.base_reachable_time_ms = 30000
net.ipv4.neigh.eth0.mcast_solicit = 3
net.ipv4.neigh.eth0.ucast_solicit = 3
net.ipv4.neigh.eth0.app_solicit = 0
net.ipv4.neigh.eth0.retrans_time = 99
net.ipv4.neigh.eth0.base_reachable_time = 30
net.ipv4.neigh.eth0.delay_first_probe_time = 5
net.ipv4.neigh.eth0.gc_stale_time = 60
net.ipv4.neigh.eth0.unres_qlen = 3
net.ipv4.neigh.eth0.proxy_qlen = 64
net.ipv4.neigh.eth0.anycast_delay = 99
net.ipv4.neigh.eth0.proxy_delay = 79
net.ipv4.neigh.eth0.locktime = 99
net.ipv4.neigh.eth0.retrans_time_ms = 1000
net.ipv4.neigh.eth0.base_reachable_time_ms = 30000
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_retrans_collapse = 1
net.ipv4.ip_default_ttl = 64
net.ipv4.ip_nonlocal_bind = 0
net.ipv4.tcp_syn_retries = 5
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_max_orphans = 65536
net.ipv4.tcp_max_tw_buckets = 65536
net.ipv4.ip_dynaddr = 0
net.ipv4.tcp_keepalive_time = 7200
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_intvl = 75
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_retries2 = 15
net.ipv4.tcp_fin_timeout = 60
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_abort_on_overflow = 0
net.ipv4.tcp_stdurg = 0
net.ipv4.tcp_rfc1337 = 0
net.ipv4.tcp_max_syn_backlog = 512
net.ipv4.ip_local_port_range = 32768	60999
net.ipv4.ip_local_reserved_ports = 
net.ipv4.igmp_max_memberships = 20
net.ipv4.igmp_max_msf = 10
net.ipv4.inet_peer_threshold = 65664
net.ipv4.inet_peer_minttl = 120
net.ipv4.inet_peer_maxttl = 600
net.ipv4.inet_peer_gc_mintime = 10
net.ipv4.inet_peer_gc_maxtime = 120
net.ipv4.tcp_orphan_retries = 0
net.ipv4.tcp_fack = 1
net.ipv4.tcp_reordering = 3
net.ipv4.tcp_ecn = 2
net.ipv4.tcp_dsack = 1
net.ipv4.tcp_mem = 68352	91136	136704
net.ipv4.tcp_wmem = 4096	16384	2916352
net.ipv4.tcp_rmem = 4096	87380	2916352
net.ipv4.tcp_app_win = 31
net.ipv4.tcp_adv_win_scale = 2
net.ipv4.tcp_tw_reuse = 0
net.ipv4.tcp_frto = 2
net.ipv4.tcp_frto_response = 0
net.ipv4.tcp_low_latency = 0
net.ipv4.tcp_no_metrics_save = 0
net.ipv4.tcp_moderate_rcvbuf = 1
net.ipv4.tcp_tso_win_divisor = 3
net.ipv4.tcp_congestion_control = cubic
net.ipv4.tcp_abc = 0
net.ipv4.tcp_mtu_probing = 0
net.ipv4.tcp_base_mss = 512
net.ipv4.tcp_workaround_signed_windows = 0
net.ipv4.tcp_challenge_ack_limit = 100
net.ipv4.tcp_limit_output_bytes = 262144
net.ipv4.tcp_dma_copybreak = 4096
net.ipv4.tcp_slow_start_after_idle = 1
net.ipv4.cipso_cache_enable = 1
net.ipv4.cipso_cache_bucket_size = 10
net.ipv4.cipso_rbm_optfmt = 0
net.ipv4.cipso_rbm_strictvalid = 1
net.ipv4.tcp_available_congestion_control = cubic reno
net.ipv4.tcp_allowed_congestion_control = cubic reno
net.ipv4.tcp_max_ssthresh = 0
net.ipv4.tcp_thin_linear_timeouts = 0
net.ipv4.tcp_thin_dupack = 0
net.ipv4.tcp_min_tso_segs = 2
net.ipv4.udp_mem = 68352	91136	136704
net.ipv4.udp_rmem_min = 4096
net.ipv4.udp_wmem_min = 4096
net.ipv4.conf.all.forwarding = 0
net.ipv4.conf.all.mc_forwarding = 0
net.ipv4.conf.all.accept_redirects = 1
net.ipv4.conf.all.secure_redirects = 1
net.ipv4.conf.all.shared_media = 1
net.ipv4.conf.all.rp_filter = 0
net.ipv4.conf.all.send_redirects = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.src_valid_mark = 0
net.ipv4.conf.all.proxy_arp = 0
net.ipv4.conf.all.medium_id = 0
net.ipv4.conf.all.bootp_relay = 0
net.ipv4.conf.all.log_martians = 0
net.ipv4.conf.all.tag = 0
net.ipv4.conf.all.arp_filter = 0
net.ipv4.conf.all.arp_announce = 0
net.ipv4.conf.all.arp_ignore = 0
net.ipv4.conf.all.arp_accept = 0
net.ipv4.conf.all.arp_notify = 0
net.ipv4.conf.all.proxy_arp_pvlan = 0
net.ipv4.conf.all.disable_xfrm = 0
net.ipv4.conf.all.disable_policy = 0
net.ipv4.conf.all.force_igmp_version = 0
net.ipv4.conf.all.promote_secondaries = 0
net.ipv4.conf.all.accept_local = 0
net.ipv4.conf.all.route_localnet = 0
net.ipv4.conf.default.forwarding = 0
net.ipv4.conf.default.mc_forwarding = 0
net.ipv4.conf.default.accept_redirects = 1
net.ipv4.conf.default.secure_redirects = 1
net.ipv4.conf.default.shared_media = 1
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.send_redirects = 1
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.default.src_valid_mark = 0
net.ipv4.conf.default.proxy_arp = 0
net.ipv4.conf.default.medium_id = 0
net.ipv4.conf.default.bootp_relay = 0
net.ipv4.conf.default.log_martians = 0
net.ipv4.conf.default.tag = 0
net.ipv4.conf.default.arp_filter = 0
net.ipv4.conf.default.arp_announce = 0
net.ipv4.conf.default.arp_ignore = 0
net.ipv4.conf.default.arp_accept = 0
net.ipv4.conf.default.arp_notify = 0
net.ipv4.conf.default.proxy_arp_pvlan = 0
net.ipv4.conf.default.disable_xfrm = 0
net.ipv4.conf.default.disable_policy = 0
net.ipv4.conf.default.force_igmp_version = 0
net.ipv4.conf.default.promote_secondaries = 0
net.ipv4.conf.default.accept_local = 0
net.ipv4.conf.default.route_localnet = 0
net.ipv4.conf.lo.forwarding = 0
net.ipv4.conf.lo.mc_forwarding = 0
net.ipv4.conf.lo.accept_redirects = 1
net.ipv4.conf.lo.secure_redirects = 1
net.ipv4.conf.lo.shared_media = 1
net.ipv4.conf.lo.rp_filter = 1
net.ipv4.conf.lo.send_redirects = 1
net.ipv4.conf.lo.accept_source_route = 0
net.ipv4.conf.lo.src_valid_mark = 0
net.ipv4.conf.lo.proxy_arp = 0
net.ipv4.conf.lo.medium_id = 0
net.ipv4.conf.lo.bootp_relay = 0
net.ipv4.conf.lo.log_martians = 0
net.ipv4.conf.lo.tag = 0
net.ipv4.conf.lo.arp_filter = 0
net.ipv4.conf.lo.arp_announce = 0
net.ipv4.conf.lo.arp_ignore = 0
net.ipv4.conf.lo.arp_accept = 0
net.ipv4.conf.lo.arp_notify = 0
net.ipv4.conf.lo.proxy_arp_pvlan = 0
net.ipv4.conf.lo.disable_xfrm = 1
net.ipv4.conf.lo.disable_policy = 1
net.ipv4.conf.lo.force_igmp_version = 0
net.ipv4.conf.lo.promote_secondaries = 0
net.ipv4.conf.lo.accept_local = 0
net.ipv4.conf.lo.route_localnet = 0
net.ipv4.conf.eth0.forwarding = 0
net.ipv4.conf.eth0.mc_forwarding = 0
net.ipv4.conf.eth0.accept_redirects = 1
net.ipv4.conf.eth0.secure_redirects = 1
net.ipv4.conf.eth0.shared_media = 1
net.ipv4.conf.eth0.rp_filter = 1
net.ipv4.conf.eth0.send_redirects = 1
net.ipv4.conf.eth0.accept_source_route = 0
net.ipv4.conf.eth0.src_valid_mark = 0
net.ipv4.conf.eth0.proxy_arp = 0
net.ipv4.conf.eth0.medium_id = 0
net.ipv4.conf.eth0.bootp_relay = 0
net.ipv4.conf.eth0.log_martians = 0
net.ipv4.conf.eth0.tag = 0
net.ipv4.conf.eth0.arp_filter = 0
net.ipv4.conf.eth0.arp_announce = 0
net.ipv4.conf.eth0.arp_ignore = 0
net.ipv4.conf.eth0.arp_accept = 0
net.ipv4.conf.eth0.arp_notify = 0
net.ipv4.conf.eth0.proxy_arp_pvlan = 0
net.ipv4.conf.eth0.disable_xfrm = 0
net.ipv4.conf.eth0.disable_policy = 0
net.ipv4.conf.eth0.force_igmp_version = 0
net.ipv4.conf.eth0.promote_secondaries = 0
net.ipv4.conf.eth0.accept_local = 0
net.ipv4.conf.eth0.route_localnet = 0
net.ipv4.ip_forward = 0
net.ipv4.xfrm4_gc_thresh = 262144
net.ipv4.ipfrag_high_thresh = 4194304
net.ipv4.ipfrag_low_thresh = 3145728
net.ipv4.ipfrag_time = 30
net.ipv4.icmp_echo_ignore_all = 0
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.icmp_errors_use_inbound_ifaddr = 0
net.ipv4.icmp_ratelimit = 1000
net.ipv4.icmp_ratemask = 6168
net.ipv4.rt_cache_rebuild_count = 4
net.ipv4.ping_group_range = 1	0
net.ipv4.ip_no_pmtu_disc = 0
net.ipv4.ip_forward_use_pmtu = 0
net.ipv4.ipfrag_secret_interval = 600
net.ipv4.ipfrag_max_dist = 64
net.ipv6.neigh.default.mcast_solicit = 3
net.ipv6.neigh.default.ucast_solicit = 3
net.ipv6.neigh.default.app_solicit = 0
net.ipv6.neigh.default.delay_first_probe_time = 5
net.ipv6.neigh.default.gc_stale_time = 60
net.ipv6.neigh.default.unres_qlen = 3
net.ipv6.neigh.default.proxy_qlen = 64
net.ipv6.neigh.default.anycast_delay = 99
net.ipv6.neigh.default.proxy_delay = 79
net.ipv6.neigh.default.locktime = 0
net.ipv6.neigh.default.retrans_time_ms = 1000
net.ipv6.neigh.default.base_reachable_time_ms = 30000
net.ipv6.neigh.default.gc_interval = 30
net.ipv6.neigh.default.gc_thresh1 = 128
net.ipv6.neigh.default.gc_thresh2 = 512
net.ipv6.neigh.default.gc_thresh3 = 1024
net.ipv6.neigh.lo.mcast_solicit = 3
net.ipv6.neigh.lo.ucast_solicit = 3
net.ipv6.neigh.lo.app_solicit = 0
net.ipv6.neigh.lo.delay_first_probe_time = 5
net.ipv6.neigh.lo.gc_stale_time = 60
net.ipv6.neigh.lo.unres_qlen = 3
net.ipv6.neigh.lo.proxy_qlen = 64
net.ipv6.neigh.lo.anycast_delay = 99
net.ipv6.neigh.lo.proxy_delay = 79
net.ipv6.neigh.lo.locktime = 0
net.ipv6.neigh.lo.retrans_time_ms = 1000
net.ipv6.neigh.lo.base_reachable_time_ms = 30000
net.ipv6.neigh.eth0.mcast_solicit = 3
net.ipv6.neigh.eth0.ucast_solicit = 3
net.ipv6.neigh.eth0.app_solicit = 0
net.ipv6.neigh.eth0.delay_first_probe_time = 5
net.ipv6.neigh.eth0.gc_stale_time = 60
net.ipv6.neigh.eth0.unres_qlen = 3
net.ipv6.neigh.eth0.proxy_qlen = 64
net.ipv6.neigh.eth0.anycast_delay = 99
net.ipv6.neigh.eth0.proxy_delay = 79
net.ipv6.neigh.eth0.locktime = 0
net.ipv6.neigh.eth0.retrans_time_ms = 1000
net.ipv6.neigh.eth0.base_reachable_time_ms = 30000
net.ipv6.xfrm6_gc_thresh = 2048
net.ipv6.conf.all.forwarding = 0
net.ipv6.conf.all.hop_limit = 64
net.ipv6.conf.all.mtu = 1280
net.ipv6.conf.all.accept_ra = 1
net.ipv6.conf.all.accept_redirects = 1
net.ipv6.conf.all.autoconf = 1
net.ipv6.conf.all.dad_transmits = 1
net.ipv6.conf.all.router_solicitations = 3
net.ipv6.conf.all.router_solicitation_interval = 4
net.ipv6.conf.all.router_solicitation_delay = 1
net.ipv6.conf.all.force_mld_version = 0
net.ipv6.conf.all.use_tempaddr = 0
net.ipv6.conf.all.temp_valid_lft = 604800
net.ipv6.conf.all.temp_prefered_lft = 86400
net.ipv6.conf.all.regen_max_retry = 5
net.ipv6.conf.all.max_desync_factor = 600
net.ipv6.conf.all.max_addresses = 16
net.ipv6.conf.all.accept_ra_defrtr = 1
net.ipv6.conf.all.accept_ra_pinfo = 1
net.ipv6.conf.all.accept_ra_rtr_pref = 1
net.ipv6.conf.all.router_probe_interval = 60
net.ipv6.conf.all.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.all.proxy_ndp = 0
net.ipv6.conf.all.accept_source_route = 0
net.ipv6.conf.all.optimistic_dad = 0
net.ipv6.conf.all.mc_forwarding = 0
net.ipv6.conf.all.disable_ipv6 = 0
net.ipv6.conf.all.accept_dad = 1
net.ipv6.conf.default.forwarding = 0
net.ipv6.conf.default.hop_limit = 64
net.ipv6.conf.default.mtu = 1280
net.ipv6.conf.default.accept_ra = 1
net.ipv6.conf.default.accept_redirects = 1
net.ipv6.conf.default.autoconf = 1
net.ipv6.conf.default.dad_transmits = 1
net.ipv6.conf.default.router_solicitations = 3
net.ipv6.conf.default.router_solicitation_interval = 4
net.ipv6.conf.default.router_solicitation_delay = 1
net.ipv6.conf.default.force_mld_version = 0
net.ipv6.conf.default.use_tempaddr = 0
net.ipv6.conf.default.temp_valid_lft = 604800
net.ipv6.conf.default.temp_prefered_lft = 86400
net.ipv6.conf.default.regen_max_retry = 5
net.ipv6.conf.default.max_desync_factor = 600
net.ipv6.conf.default.max_addresses = 16
net.ipv6.conf.default.accept_ra_defrtr = 1
net.ipv6.conf.default.accept_ra_pinfo = 1
net.ipv6.conf.default.accept_ra_rtr_pref = 1
net.ipv6.conf.default.router_probe_interval = 60
net.ipv6.conf.default.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.default.proxy_ndp = 0
net.ipv6.conf.default.accept_source_route = 0
net.ipv6.conf.default.optimistic_dad = 0
net.ipv6.conf.default.mc_forwarding = 0
net.ipv6.conf.default.disable_ipv6 = 0
net.ipv6.conf.default.accept_dad = 1
net.ipv6.conf.lo.forwarding = 0
net.ipv6.conf.lo.hop_limit = 64
net.ipv6.conf.lo.mtu = 65536
net.ipv6.conf.lo.accept_ra = 1
net.ipv6.conf.lo.accept_redirects = 1
net.ipv6.conf.lo.autoconf = 1
net.ipv6.conf.lo.dad_transmits = 1
net.ipv6.conf.lo.router_solicitations = 3
net.ipv6.conf.lo.router_solicitation_interval = 4
net.ipv6.conf.lo.router_solicitation_delay = 1
net.ipv6.conf.lo.force_mld_version = 0
net.ipv6.conf.lo.use_tempaddr = -1
net.ipv6.conf.lo.temp_valid_lft = 604800
net.ipv6.conf.lo.temp_prefered_lft = 86400
net.ipv6.conf.lo.regen_max_retry = 5
net.ipv6.conf.lo.max_desync_factor = 600
net.ipv6.conf.lo.max_addresses = 16
net.ipv6.conf.lo.accept_ra_defrtr = 1
net.ipv6.conf.lo.accept_ra_pinfo = 1
net.ipv6.conf.lo.accept_ra_rtr_pref = 1
net.ipv6.conf.lo.router_probe_interval = 60
net.ipv6.conf.lo.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.lo.proxy_ndp = 0
net.ipv6.conf.lo.accept_source_route = 0
net.ipv6.conf.lo.optimistic_dad = 0
net.ipv6.conf.lo.mc_forwarding = 0
net.ipv6.conf.lo.disable_ipv6 = 0
net.ipv6.conf.lo.accept_dad = -1
net.ipv6.conf.eth0.forwarding = 0
net.ipv6.conf.eth0.hop_limit = 64
net.ipv6.conf.eth0.mtu = 1500
net.ipv6.conf.eth0.accept_ra = 1
net.ipv6.conf.eth0.accept_redirects = 1
net.ipv6.conf.eth0.autoconf = 1
net.ipv6.conf.eth0.dad_transmits = 1
net.ipv6.conf.eth0.router_solicitations = 3
net.ipv6.conf.eth0.router_solicitation_interval = 4
net.ipv6.conf.eth0.router_solicitation_delay = 1
net.ipv6.conf.eth0.force_mld_version = 0
net.ipv6.conf.eth0.use_tempaddr = 0
net.ipv6.conf.eth0.temp_valid_lft = 604800
net.ipv6.conf.eth0.temp_prefered_lft = 86400
net.ipv6.conf.eth0.regen_max_retry = 5
net.ipv6.conf.eth0.max_desync_factor = 600
net.ipv6.conf.eth0.max_addresses = 16
net.ipv6.conf.eth0.accept_ra_defrtr = 1
net.ipv6.conf.eth0.accept_ra_pinfo = 1
net.ipv6.conf.eth0.accept_ra_rtr_pref = 1
net.ipv6.conf.eth0.router_probe_interval = 60
net.ipv6.conf.eth0.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.eth0.proxy_ndp = 0
net.ipv6.conf.eth0.accept_source_route = 0
net.ipv6.conf.eth0.optimistic_dad = 0
net.ipv6.conf.eth0.mc_forwarding = 0
net.ipv6.conf.eth0.disable_ipv6 = 0
net.ipv6.conf.eth0.accept_dad = 1
net.ipv6.ip6frag_high_thresh = 4194304
net.ipv6.ip6frag_low_thresh = 3145728
net.ipv6.ip6frag_time = 60
net.ipv6.route.gc_thresh = 1024
net.ipv6.route.max_size = 16384
net.ipv6.route.gc_min_interval = 0
net.ipv6.route.gc_timeout = 60
net.ipv6.route.gc_interval = 30
net.ipv6.route.gc_elasticity = 0
net.ipv6.route.mtu_expires = 600
net.ipv6.route.min_adv_mss = 1
net.ipv6.route.gc_min_interval_ms = 500
net.ipv6.icmp.ratelimit = 1000
net.ipv6.bindv6only = 0
net.ipv6.nf_conntrack_frag6_timeout = 60
net.ipv6.nf_conntrack_frag6_low_thresh = 3145728
net.ipv6.nf_conntrack_frag6_high_thresh = 4194304
net.ipv6.ip6frag_secret_interval = 600
net.ipv6.mld_max_msf = 64
net.nf_conntrack_max = 65536
net.unix.max_dgram_qlen = 10
crypto.fips_enabled = 0

各項目は、/proc/sys 以下のファイルに対応している。

[root@localhost CentOS6 ~]#sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 0
[root@localhost CentOS6 ~]#cat /proc/sys/net/ipv4/ip_forward
0

net.core に関するもののみ（/proc/sys/net/core/ 以下のみ）表示する。

[root@localhost CentOS6 ~]#sysctl net.core
net.core.somaxconn = 128
net.core.xfrm_aevent_etime = 10
net.core.xfrm_aevent_rseqth = 2
net.core.xfrm_larval_drop = 1
net.core.xfrm_acq_expires = 30
net.core.wmem_max = 112640
net.core.rmem_max = 112640
net.core.wmem_default = 112640
net.core.rmem_default = 112640
net.core.dev_weight = 64
net.core.netdev_max_backlog = 1000
net.core.netdev_rss_key = 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
net.core.message_cost = 5
net.core.message_burst = 10
net.core.optmem_max = 10240
net.core.rps_sock_flow_entries = 0
net.core.busy_poll = 0
net.core.busy_read = 0
net.core.default_qdisc = pfifo_fast
net.core.netdev_budget = 300
net.core.warnings = 1