目次
はじめに
こんにちは。ネットワークエンジニアの「だいまる」です。
今回もLPIC Level2学習の一環として、「カーネル」について勉強してみたので、まとめていきたいと思います。
カーネルとは？
そもそもカーネルとは何者なのか？
なんとなくわかっていた気ではいましたが、まとめてみるとまだまだ理解が浅いなと感じましたが、現状の知識のアウトプットとしてまとめていきたいと思います。
知識の深掘りのために以下の本を買って、本記事を更新していきたいと思います！
カーネルの役割とは？
そもそもカーネルとは「OS（オペレーションシステム）の基本役割を担うソフトウェア」です。
基本役割とは、主に以下の「5分野の制御・管理」を行っています。
| 項目 | 詳細 |
| メモリ管理 | メモリリソースの管理 |
| プロセス管理 | 各プログラムの実行に必要なプロセス管理 |
| デバイスドライバ | 各種デバイスと接続を行うためのドライバ管理 |
| システムコール/セキュリティ | 特権モードで利用できる機能の管理 |
| ファイルシステム管理 | ファイル・ディレクトリの管理 |
カーネルはPCやサーバの根幹となる機能のため、通常の一般ユーザ（私達）が簡単に変更・制御できる権限を持っているとはちゃめちゃなことになります。
そのため、「特権モード」と呼ばれる利用できるユーザが制限されているモードでのみ変更・制御が可能となります。
ソースコードが見たいなら見てみよう！
普段意識することはないカーネルのソースコードは、実は「kernel.org」でみることができます。
基本はC言語で作成されており、このソースコードをサーバやPCにインストール、ビルドすることで利用可能となります。
もし、自分自身でカーネルを作ってみたいという方や自分好みのカーネルにしてみたいという方は、参考になると思います。
私は、以下の本を理解してから挑んでみようと思っています。
カーネルのパラメータを見てみよう！
カーネルパラメータの確認や変更、作成は主に以下3つの適したパターンで実施します。
| パターン | 詳細 |
| パターン① | /proc/sys配下のConfigファイルを確認 |
| パターン② | sysctlコマンドによる確認 |
| パターン③ | /etc/sysctl.confの確認 |
パターン①：/proc/sys配下のConfigファイル確認
最初のパターンは、「/proc/sys配下に存在するConfigファイル」の確認です。
「/proc/sys」配下には多数のディレクトリ、ファイルが保存されています。
これらのファイルは、カーネルのパラメータとして定義されている物が多いです。
一般的に「catコマンド」で内容の確認、「echoコマンド」でパラメータの変更を行います。
daimaru@raspi-test:~ $ sudo ls /proc/sys/
debug dev fs kernel net sunrpc user vm
daimaru@raspi-test:~ $ sudo cat /proc/sys/kernel/hostname
raspi-testしかし、「echoコマンド」による変更はLinuxサーバの電源Off/Onや再起動時に初期値に戻ってしまうので注意が必要です。
パターン②：sysctlコマンドによる確認
2つ目のパターンは「sysctlコマンド」による状態確認や設定変更になります。
「sysctlコマンド」の書式や各オプションは以下の通りとなります。
sysctl (option) （変数等）| オプション | 詳細 |
| -a | 全変数と値の出力 |
| -n （変数の指定） | 指定した変数の出力 |
| -e | エラーの変数は非表示 |
| -w [変数名] = [値] | パラメータの変更 |
| -p [file名・パス] | 指定ファイルの読込 |
| -q | エラーメッセージ出力 |
| -f | 全ファイルから読み込み |
実機確認では、オプション「-a」の出力結果を記載しておきます。
sysctl -a の出力結果
daimaru@raspi-test:~ $ sudo sysctl -a
debug.kprobes-optimization = 1
dev.scsi.logging_level = 0
dev.tty.ldisc_autoload = 1
dev.tty.legacy_tiocsti = 1
fs.aio-max-nr = 65536
fs.aio-nr = 0
fs.binfmt_misc.python3/11 = enabled
fs.binfmt_misc.python3/11 = interpreter /usr/bin/python3.11
fs.binfmt_misc.python3/11 = flags:
fs.binfmt_misc.python3/11 = offset 0
fs.binfmt_misc.python3/11 = magic a70d0d0a
fs.binfmt_misc.status = enabled
fs.dentry-state = 23991 17801 45 0 2808 0
fs.dir-notify-enable = 1
fs.epoll.max_user_watches = 364780
fs.fanotify.max_queued_events = 16384
fs.fanotify.max_user_groups = 128
fs.fanotify.max_user_marks = 11375
fs.file-max = 2147483647
fs.file-nr = 3264 0 2147483647
fs.inode-nr = 21486 591
fs.inode-state = 21486 591 0 0 0 0 0
fs.inotify.max_queued_events = 16384
fs.inotify.max_user_instances = 128
fs.inotify.max_user_watches = 10582
fs.lease-break-time = 45
fs.leases-enable = 1
fs.mount-max = 100000
fs.mqueue.msg_default = 10
fs.mqueue.msg_max = 10
fs.mqueue.msgsize_default = 8192
fs.mqueue.msgsize_max = 8192
fs.mqueue.queues_max = 256
fs.nfs.idmap_cache_timeout = 600
fs.nfs.nfs_callback_tcpport = 0
fs.nfs.nfs_congestion_kb = 31040
fs.nfs.nfs_mountpoint_timeout = 500
fs.nfs.nlm_grace_period = 0
fs.nfs.nlm_tcpport = 0
fs.nfs.nlm_timeout = 10
fs.nfs.nlm_udpport = 0
fs.nfs.nsm_local_state = 0
fs.nfs.nsm_use_hostnames = 0
fs.nr_open = 1048576
fs.overflowgid = 65534
fs.overflowuid = 65534
fs.pipe-max-size = 1048576
fs.pipe-user-pages-hard = 0
fs.pipe-user-pages-soft = 16384
fs.protected_fifos = 1
fs.protected_hardlinks = 1
fs.protected_regular = 2
fs.protected_symlinks = 1
fs.quota.allocated_dquots = 0
fs.quota.cache_hits = 0
fs.quota.drops = 0
fs.quota.free_dquots = 0
fs.quota.lookups = 0
fs.quota.reads = 0
fs.quota.syncs = 0
fs.quota.writes = 0
fs.suid_dumpable = 0
kernel.acct = 4 2 30
kernel.arch = armv7l
kernel.auto_msgmni = 0
kernel.bpf_stats_enabled = 0
kernel.cad_pid = 1
kernel.cap_last_cap = 40
kernel.core_pattern = core
kernel.core_pipe_limit = 0
kernel.core_uses_pid = 0
kernel.ctrl-alt-del = 0
kernel.dmesg_restrict = 0
kernel.domainname = (none)
kernel.ftrace_dump_on_oops = 0
kernel.ftrace_enabled = 1
kernel.hostname = raspi-test
kernel.hotplug =
kernel.hung_task_all_cpu_backtrace = 0
kernel.hung_task_check_count = 32768
kernel.hung_task_check_interval_secs = 0
kernel.hung_task_panic = 0
kernel.hung_task_timeout_secs = 120
kernel.hung_task_warnings = 10
kernel.io_uring_disabled = 0
kernel.io_uring_group = -1
kernel.keys.gc_delay = 300
kernel.keys.maxbytes = 20000
kernel.keys.maxkeys = 200
kernel.keys.root_maxbytes = 25000000
kernel.keys.root_maxkeys = 1000000
kernel.kptr_restrict = 0
kernel.latencytop = 0
kernel.max_lock_depth = 1024
kernel.max_rcu_stall_to_panic = 0
kernel.modprobe = /sbin/modprobe
kernel.modules_disabled = 0
kernel.msgmax = 8192
kernel.msgmnb = 16384
kernel.msgmni = 32000
kernel.ngroups_max = 65536
kernel.oops_all_cpu_backtrace = 0
kernel.oops_limit = 10000
kernel.osrelease = 6.6.51+rpt-rpi-v7
kernel.ostype = Linux
kernel.overflowgid = 65534
kernel.overflowuid = 65534
kernel.panic = 0
kernel.panic_on_oops = 0
kernel.panic_on_rcu_stall = 0
kernel.panic_on_warn = 0
kernel.panic_print = 0
kernel.perf_cpu_time_max_percent = 25
kernel.perf_event_max_contexts_per_stack = 8
kernel.perf_event_max_sample_rate = 100000
kernel.perf_event_max_stack = 127
kernel.perf_event_mlock_kb = 516
kernel.perf_event_paranoid = 2
kernel.pid_max = 32768
kernel.poweroff_cmd = /sbin/poweroff
kernel.print-fatal-signals = 0
kernel.printk = 3 4 1 3
kernel.printk_delay = 0
kernel.printk_devkmsg = on
kernel.printk_ratelimit = 5
kernel.printk_ratelimit_burst = 10
kernel.pty.max = 4096
kernel.pty.nr = 2
kernel.pty.reserve = 1024
kernel.random.boot_id = 803f350d-9591-45d5-97c5-f47fbfc7a451
kernel.random.entropy_avail = 256
kernel.random.poolsize = 256
kernel.random.urandom_min_reseed_secs = 60
kernel.random.uuid = 50f39cf4-010d-4acd-a0e0-931195c64342
kernel.random.write_wakeup_threshold = 256
kernel.randomize_va_space = 2
kernel.real-root-dev = 0
kernel.sched_autogroup_enabled = 1
kernel.sched_cfs_bandwidth_slice_us = 5000
kernel.sched_child_runs_first = 0
kernel.sched_deadline_period_max_us = 4194304
kernel.sched_deadline_period_min_us = 100
kernel.sched_rr_timeslice_ms = 100
kernel.sched_rt_period_us = 1000000
kernel.sched_rt_runtime_us = 950000
kernel.sched_schedstats = 0
kernel.seccomp.actions_avail = kill_process kill_thread trap errno user_notif trace log allow
kernel.seccomp.actions_logged = kill_process kill_thread trap errno user_notif trace log
kernel.sem = 32000 1024000000 500 32000
kernel.shm_rmid_forced = 0
kernel.shmall = 4278190079
kernel.shmmax = 4278190079
kernel.shmmni = 4096
kernel.stack_tracer_enabled = 0
kernel.sysctl_writes_strict = 1
kernel.sysrq = 502
kernel.tainted = 1024
kernel.task_delayacct = 0
kernel.threads-max = 10375
kernel.timer_migration = 1
kernel.traceoff_on_warning = 0
kernel.tracepoint_printk = 0
kernel.unprivileged_bpf_disabled = 2
kernel.usermodehelper.bset = 4294967295 511
kernel.usermodehelper.inheritable = 4294967295 511
kernel.version = #1 SMP Raspbian 1:6.6.51-1+rpt3 (2024-10-08)
kernel.warn_limit = 0
net.core.busy_poll = 0
net.core.busy_read = 0
net.core.default_qdisc = pfifo_fast
net.core.dev_weight = 64
net.core.dev_weight_rx_bias = 1
net.core.dev_weight_tx_bias = 1
net.core.devconf_inherit_init_net = 0
net.core.fb_tunnels_only_for_init_net = 0
net.core.flow_limit_cpu_bitmap = 0
net.core.flow_limit_table_len = 4096
net.core.gro_normal_batch = 8
net.core.high_order_alloc_disable = 0
net.core.max_skb_frags = 17
net.core.mem_pcpu_rsv = 256
net.core.message_burst = 10
net.core.message_cost = 5
net.core.netdev_budget = 300
net.core.netdev_budget_usecs = 20000
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.netdev_tstamp_prequeue = 1
net.core.netdev_unregister_timeout_secs = 10
net.core.optmem_max = 10240
net.core.rmem_default = 180224
net.core.rmem_max = 180224
net.core.rps_default_mask = 0
net.core.rps_sock_flow_entries = 0
net.core.skb_defer_max = 64
net.core.somaxconn = 4096
net.core.tstamp_allow_data = 1
net.core.txrehash = 1
net.core.warnings = 0
net.core.wmem_default = 180224
net.core.wmem_max = 180224
net.core.xfrm_acq_expires = 30
net.core.xfrm_aevent_etime = 10
net.core.xfrm_aevent_rseqth = 2
net.core.xfrm_larval_drop = 1
net.ipv4.conf.all.accept_local = 0
net.ipv4.conf.all.accept_redirects = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.arp_accept = 0
net.ipv4.conf.all.arp_announce = 0
net.ipv4.conf.all.arp_evict_nocarrier = 1
net.ipv4.conf.all.arp_filter = 0
net.ipv4.conf.all.arp_ignore = 0
net.ipv4.conf.all.arp_notify = 0
net.ipv4.conf.all.bc_forwarding = 0
net.ipv4.conf.all.bootp_relay = 0
net.ipv4.conf.all.disable_policy = 0
net.ipv4.conf.all.disable_xfrm = 0
net.ipv4.conf.all.drop_gratuitous_arp = 0
net.ipv4.conf.all.drop_unicast_in_l2_multicast = 0
net.ipv4.conf.all.force_igmp_version = 0
net.ipv4.conf.all.forwarding = 0
net.ipv4.conf.all.igmpv2_unsolicited_report_interval = 10000
net.ipv4.conf.all.igmpv3_unsolicited_report_interval = 1000
net.ipv4.conf.all.ignore_routes_with_linkdown = 0
net.ipv4.conf.all.log_martians = 0
net.ipv4.conf.all.mc_forwarding = 0
net.ipv4.conf.all.medium_id = 0
net.ipv4.conf.all.promote_secondaries = 0
net.ipv4.conf.all.proxy_arp = 0
net.ipv4.conf.all.proxy_arp_pvlan = 0
net.ipv4.conf.all.route_localnet = 0
net.ipv4.conf.all.rp_filter = 0
net.ipv4.conf.all.secure_redirects = 1
net.ipv4.conf.all.send_redirects = 1
net.ipv4.conf.all.shared_media = 1
net.ipv4.conf.all.src_valid_mark = 0
net.ipv4.conf.all.tag = 0
net.ipv4.conf.default.accept_local = 0
net.ipv4.conf.default.accept_redirects = 1
net.ipv4.conf.default.accept_source_route = 1
net.ipv4.conf.default.arp_accept = 0
net.ipv4.conf.default.arp_announce = 0
net.ipv4.conf.default.arp_evict_nocarrier = 1
net.ipv4.conf.default.arp_filter = 0
net.ipv4.conf.default.arp_ignore = 0
net.ipv4.conf.default.arp_notify = 0
net.ipv4.conf.default.bc_forwarding = 0
net.ipv4.conf.default.bootp_relay = 0
net.ipv4.conf.default.disable_policy = 0
net.ipv4.conf.default.disable_xfrm = 0
net.ipv4.conf.default.drop_gratuitous_arp = 0
net.ipv4.conf.default.drop_unicast_in_l2_multicast = 0
net.ipv4.conf.default.force_igmp_version = 0
net.ipv4.conf.default.forwarding = 0
net.ipv4.conf.default.igmpv2_unsolicited_report_interval = 10000
net.ipv4.conf.default.igmpv3_unsolicited_report_interval = 1000
net.ipv4.conf.default.ignore_routes_with_linkdown = 0
net.ipv4.conf.default.log_martians = 0
net.ipv4.conf.default.mc_forwarding = 0
net.ipv4.conf.default.medium_id = 0
net.ipv4.conf.default.promote_secondaries = 0
net.ipv4.conf.default.proxy_arp = 0
net.ipv4.conf.default.proxy_arp_pvlan = 0
net.ipv4.conf.default.route_localnet = 0
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.default.secure_redirects = 1
net.ipv4.conf.default.send_redirects = 1
net.ipv4.conf.default.shared_media = 1
net.ipv4.conf.default.src_valid_mark = 0
net.ipv4.conf.default.tag = 0
net.ipv4.conf.eth0.accept_local = 0
net.ipv4.conf.eth0.accept_redirects = 1
net.ipv4.conf.eth0.accept_source_route = 1
net.ipv4.conf.eth0.arp_accept = 0
net.ipv4.conf.eth0.arp_announce = 0
net.ipv4.conf.eth0.arp_evict_nocarrier = 1
net.ipv4.conf.eth0.arp_filter = 0
net.ipv4.conf.eth0.arp_ignore = 0
net.ipv4.conf.eth0.arp_notify = 0
net.ipv4.conf.eth0.bc_forwarding = 0
net.ipv4.conf.eth0.bootp_relay = 0
net.ipv4.conf.eth0.disable_policy = 0
net.ipv4.conf.eth0.disable_xfrm = 0
net.ipv4.conf.eth0.drop_gratuitous_arp = 0
net.ipv4.conf.eth0.drop_unicast_in_l2_multicast = 0
net.ipv4.conf.eth0.force_igmp_version = 0
net.ipv4.conf.eth0.forwarding = 0
net.ipv4.conf.eth0.igmpv2_unsolicited_report_interval = 10000
net.ipv4.conf.eth0.igmpv3_unsolicited_report_interval = 1000
net.ipv4.conf.eth0.ignore_routes_with_linkdown = 0
net.ipv4.conf.eth0.log_martians = 0
net.ipv4.conf.eth0.mc_forwarding = 0
net.ipv4.conf.eth0.medium_id = 0
net.ipv4.conf.eth0.promote_secondaries = 0
net.ipv4.conf.eth0.proxy_arp = 0
net.ipv4.conf.eth0.proxy_arp_pvlan = 0
net.ipv4.conf.eth0.route_localnet = 0
net.ipv4.conf.eth0.rp_filter = 0
net.ipv4.conf.eth0.secure_redirects = 1
net.ipv4.conf.eth0.send_redirects = 1
net.ipv4.conf.eth0.shared_media = 1
net.ipv4.conf.eth0.src_valid_mark = 0
net.ipv4.conf.eth0.tag = 0
net.ipv4.conf.lo.accept_local = 0
net.ipv4.conf.lo.accept_redirects = 1
net.ipv4.conf.lo.accept_source_route = 1
net.ipv4.conf.lo.arp_accept = 0
net.ipv4.conf.lo.arp_announce = 0
net.ipv4.conf.lo.arp_evict_nocarrier = 1
net.ipv4.conf.lo.arp_filter = 0
net.ipv4.conf.lo.arp_ignore = 0
net.ipv4.conf.lo.arp_notify = 0
net.ipv4.conf.lo.bc_forwarding = 0
net.ipv4.conf.lo.bootp_relay = 0
net.ipv4.conf.lo.disable_policy = 1
net.ipv4.conf.lo.disable_xfrm = 1
net.ipv4.conf.lo.drop_gratuitous_arp = 0
net.ipv4.conf.lo.drop_unicast_in_l2_multicast = 0
net.ipv4.conf.lo.force_igmp_version = 0
net.ipv4.conf.lo.forwarding = 0
net.ipv4.conf.lo.igmpv2_unsolicited_report_interval = 10000
net.ipv4.conf.lo.igmpv3_unsolicited_report_interval = 1000
net.ipv4.conf.lo.ignore_routes_with_linkdown = 0
net.ipv4.conf.lo.log_martians = 0
net.ipv4.conf.lo.mc_forwarding = 0
net.ipv4.conf.lo.medium_id = 0
net.ipv4.conf.lo.promote_secondaries = 0
net.ipv4.conf.lo.proxy_arp = 0
net.ipv4.conf.lo.proxy_arp_pvlan = 0
net.ipv4.conf.lo.route_localnet = 0
net.ipv4.conf.lo.rp_filter = 0
net.ipv4.conf.lo.secure_redirects = 1
net.ipv4.conf.lo.send_redirects = 1
net.ipv4.conf.lo.shared_media = 1
net.ipv4.conf.lo.src_valid_mark = 0
net.ipv4.conf.lo.tag = 0
net.ipv4.conf.wlan0.accept_local = 0
net.ipv4.conf.wlan0.accept_redirects = 1
net.ipv4.conf.wlan0.accept_source_route = 1
net.ipv4.conf.wlan0.arp_accept = 0
net.ipv4.conf.wlan0.arp_announce = 0
net.ipv4.conf.wlan0.arp_evict_nocarrier = 1
net.ipv4.conf.wlan0.arp_filter = 0
net.ipv4.conf.wlan0.arp_ignore = 0
net.ipv4.conf.wlan0.arp_notify = 0
net.ipv4.conf.wlan0.bc_forwarding = 0
net.ipv4.conf.wlan0.bootp_relay = 0
net.ipv4.conf.wlan0.disable_policy = 0
net.ipv4.conf.wlan0.disable_xfrm = 0
net.ipv4.conf.wlan0.drop_gratuitous_arp = 0
net.ipv4.conf.wlan0.drop_unicast_in_l2_multicast = 0
net.ipv4.conf.wlan0.force_igmp_version = 0
net.ipv4.conf.wlan0.forwarding = 0
net.ipv4.conf.wlan0.igmpv2_unsolicited_report_interval = 10000
net.ipv4.conf.wlan0.igmpv3_unsolicited_report_interval = 1000
net.ipv4.conf.wlan0.ignore_routes_with_linkdown = 0
net.ipv4.conf.wlan0.log_martians = 0
net.ipv4.conf.wlan0.mc_forwarding = 0
net.ipv4.conf.wlan0.medium_id = 0
net.ipv4.conf.wlan0.promote_secondaries = 0
net.ipv4.conf.wlan0.proxy_arp = 0
net.ipv4.conf.wlan0.proxy_arp_pvlan = 0
net.ipv4.conf.wlan0.route_localnet = 0
net.ipv4.conf.wlan0.rp_filter = 0
net.ipv4.conf.wlan0.secure_redirects = 1
net.ipv4.conf.wlan0.send_redirects = 1
net.ipv4.conf.wlan0.shared_media = 1
net.ipv4.conf.wlan0.src_valid_mark = 0
net.ipv4.conf.wlan0.tag = 0
net.ipv4.fib_multipath_hash_fields = 7
net.ipv4.fib_multipath_hash_policy = 0
net.ipv4.fib_multipath_use_neigh = 0
net.ipv4.fib_notify_on_flag_change = 0
net.ipv4.fib_sync_mem = 524288
net.ipv4.fwmark_reflect = 0
net.ipv4.icmp_echo_enable_probe = 0
net.ipv4.icmp_echo_ignore_all = 0
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_errors_use_inbound_ifaddr = 0
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.icmp_msgs_burst = 50
net.ipv4.icmp_msgs_per_sec = 1000
net.ipv4.icmp_ratelimit = 1000
net.ipv4.icmp_ratemask = 6168
net.ipv4.igmp_link_local_mcast_reports = 1
net.ipv4.igmp_max_memberships = 20
net.ipv4.igmp_max_msf = 10
net.ipv4.igmp_qrv = 2
net.ipv4.inet_peer_maxttl = 600
net.ipv4.inet_peer_minttl = 120
net.ipv4.inet_peer_threshold = 65664
net.ipv4.ip_autobind_reuse = 0
net.ipv4.ip_default_ttl = 64
net.ipv4.ip_dynaddr = 0
net.ipv4.ip_early_demux = 1
net.ipv4.ip_forward = 0
net.ipv4.ip_forward_update_priority = 1
net.ipv4.ip_forward_use_pmtu = 0
net.ipv4.ip_local_port_range = 32768 60999
net.ipv4.ip_local_reserved_ports =
net.ipv4.ip_no_pmtu_disc = 0
net.ipv4.ip_nonlocal_bind = 0
net.ipv4.ip_unprivileged_port_start = 1024
net.ipv4.ipfrag_high_thresh = 4194304
net.ipv4.ipfrag_low_thresh = 3145728
net.ipv4.ipfrag_max_dist = 64
net.ipv4.ipfrag_secret_interval = 0
net.ipv4.ipfrag_time = 30
net.ipv4.neigh.default.anycast_delay = 100
net.ipv4.neigh.default.app_solicit = 0
net.ipv4.neigh.default.base_reachable_time_ms = 30000
net.ipv4.neigh.default.delay_first_probe_time = 5
net.ipv4.neigh.default.gc_interval = 30
net.ipv4.neigh.default.gc_stale_time = 60
net.ipv4.neigh.default.gc_thresh1 = 128
net.ipv4.neigh.default.gc_thresh2 = 512
net.ipv4.neigh.default.gc_thresh3 = 1024
net.ipv4.neigh.default.interval_probe_time_ms = 5000
net.ipv4.neigh.default.locktime = 100
net.ipv4.neigh.default.mcast_resolicit = 0
net.ipv4.neigh.default.mcast_solicit = 3
net.ipv4.neigh.default.proxy_delay = 80
net.ipv4.neigh.default.proxy_qlen = 64
net.ipv4.neigh.default.retrans_time_ms = 1000
net.ipv4.neigh.default.ucast_solicit = 3
net.ipv4.neigh.default.unres_qlen = 91
net.ipv4.neigh.default.unres_qlen_bytes = 180224
net.ipv4.neigh.eth0.anycast_delay = 100
net.ipv4.neigh.eth0.app_solicit = 0
net.ipv4.neigh.eth0.base_reachable_time_ms = 30000
net.ipv4.neigh.eth0.delay_first_probe_time = 5
net.ipv4.neigh.eth0.gc_stale_time = 60
net.ipv4.neigh.eth0.interval_probe_time_ms = 5000
net.ipv4.neigh.eth0.locktime = 100
net.ipv4.neigh.eth0.mcast_resolicit = 0
net.ipv4.neigh.eth0.mcast_solicit = 3
net.ipv4.neigh.eth0.proxy_delay = 80
net.ipv4.neigh.eth0.proxy_qlen = 64
net.ipv4.neigh.eth0.retrans_time_ms = 1000
net.ipv4.neigh.eth0.ucast_solicit = 3
net.ipv4.neigh.eth0.unres_qlen = 91
net.ipv4.neigh.eth0.unres_qlen_bytes = 180224
net.ipv4.neigh.lo.anycast_delay = 100
net.ipv4.neigh.lo.app_solicit = 0
net.ipv4.neigh.lo.base_reachable_time_ms = 30000
net.ipv4.neigh.lo.delay_first_probe_time = 5
net.ipv4.neigh.lo.gc_stale_time = 60
net.ipv4.neigh.lo.interval_probe_time_ms = 5000
net.ipv4.neigh.lo.locktime = 100
net.ipv4.neigh.lo.mcast_resolicit = 0
net.ipv4.neigh.lo.mcast_solicit = 3
net.ipv4.neigh.lo.proxy_delay = 80
net.ipv4.neigh.lo.proxy_qlen = 64
net.ipv4.neigh.lo.retrans_time_ms = 1000
net.ipv4.neigh.lo.ucast_solicit = 3
net.ipv4.neigh.lo.unres_qlen = 91
net.ipv4.neigh.lo.unres_qlen_bytes = 180224
net.ipv4.neigh.wlan0.anycast_delay = 100
net.ipv4.neigh.wlan0.app_solicit = 0
net.ipv4.neigh.wlan0.base_reachable_time_ms = 30000
net.ipv4.neigh.wlan0.delay_first_probe_time = 5
net.ipv4.neigh.wlan0.gc_stale_time = 60
net.ipv4.neigh.wlan0.interval_probe_time_ms = 5000
net.ipv4.neigh.wlan0.locktime = 100
net.ipv4.neigh.wlan0.mcast_resolicit = 0
net.ipv4.neigh.wlan0.mcast_solicit = 3
net.ipv4.neigh.wlan0.proxy_delay = 80
net.ipv4.neigh.wlan0.proxy_qlen = 64
net.ipv4.neigh.wlan0.retrans_time_ms = 1000
net.ipv4.neigh.wlan0.ucast_solicit = 3
net.ipv4.neigh.wlan0.unres_qlen = 91
net.ipv4.neigh.wlan0.unres_qlen_bytes = 180224
net.ipv4.nexthop_compat_mode = 1
net.ipv4.ping_group_range = 0 2147483647
net.ipv4.raw_l3mdev_accept = 1
net.ipv4.route.error_burst = 500
net.ipv4.route.error_cost = 100
net.ipv4.route.gc_elasticity = 8
net.ipv4.route.gc_interval = 60
net.ipv4.route.gc_min_interval = 0
net.ipv4.route.gc_min_interval_ms = 500
net.ipv4.route.gc_thresh = -1
net.ipv4.route.gc_timeout = 300
net.ipv4.route.max_size = 2147483647
net.ipv4.route.min_adv_mss = 256
net.ipv4.route.min_pmtu = 552
net.ipv4.route.mtu_expires = 600
net.ipv4.route.redirect_load = 2
net.ipv4.route.redirect_number = 9
net.ipv4.route.redirect_silence = 2048
net.ipv4.tcp_abort_on_overflow = 0
net.ipv4.tcp_adv_win_scale = 1
net.ipv4.tcp_allowed_congestion_control = reno cubic
net.ipv4.tcp_app_win = 31
net.ipv4.tcp_autocorking = 1
net.ipv4.tcp_available_congestion_control = reno cubic
net.ipv4.tcp_available_ulp =
net.ipv4.tcp_base_mss = 1024
net.ipv4.tcp_challenge_ack_limit = 2147483647
net.ipv4.tcp_child_ehash_entries = 0
net.ipv4.tcp_comp_sack_delay_ns = 1000000
net.ipv4.tcp_comp_sack_nr = 44
net.ipv4.tcp_comp_sack_slack_ns = 100000
net.ipv4.tcp_congestion_control = cubic
net.ipv4.tcp_dsack = 1
net.ipv4.tcp_early_demux = 1
net.ipv4.tcp_early_retrans = 3
net.ipv4.tcp_ecn = 2
net.ipv4.tcp_ecn_fallback = 1
net.ipv4.tcp_ehash_entries = 8192
net.ipv4.tcp_fack = 0
net.ipv4.tcp_fastopen = 1
net.ipv4.tcp_fastopen_blackhole_timeout_sec = 0
net.ipv4.tcp_fastopen_key = 00000000-00000000-00000000-00000000
net.ipv4.tcp_fin_timeout = 60
net.ipv4.tcp_frto = 2
net.ipv4.tcp_fwmark_accept = 0
net.ipv4.tcp_invalid_ratelimit = 500
net.ipv4.tcp_keepalive_intvl = 75
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_time = 7200
net.ipv4.tcp_l3mdev_accept = 0
net.ipv4.tcp_limit_output_bytes = 1048576
net.ipv4.tcp_low_latency = 0
net.ipv4.tcp_max_orphans = 4096
net.ipv4.tcp_max_reordering = 300
net.ipv4.tcp_max_syn_backlog = 128
net.ipv4.tcp_max_tw_buckets = 4096
net.ipv4.tcp_mem = 10785 14381 21570
net.ipv4.tcp_migrate_req = 0
net.ipv4.tcp_min_rtt_wlen = 300
net.ipv4.tcp_min_snd_mss = 48
net.ipv4.tcp_min_tso_segs = 2
net.ipv4.tcp_moderate_rcvbuf = 1
net.ipv4.tcp_mtu_probe_floor = 48
net.ipv4.tcp_mtu_probing = 0
net.ipv4.tcp_no_metrics_save = 0
net.ipv4.tcp_no_ssthresh_metrics_save = 1
net.ipv4.tcp_notsent_lowat = 4294967295
net.ipv4.tcp_orphan_retries = 0
net.ipv4.tcp_pacing_ca_ratio = 120
net.ipv4.tcp_pacing_ss_ratio = 200
net.ipv4.tcp_plb_cong_thresh = 128
net.ipv4.tcp_plb_enabled = 0
net.ipv4.tcp_plb_idle_rehash_rounds = 3
net.ipv4.tcp_plb_rehash_rounds = 12
net.ipv4.tcp_plb_suspend_rto_sec = 60
net.ipv4.tcp_probe_interval = 600
net.ipv4.tcp_probe_threshold = 8
net.ipv4.tcp_recovery = 1
net.ipv4.tcp_reflect_tos = 0
net.ipv4.tcp_reordering = 3
net.ipv4.tcp_retrans_collapse = 1
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_retries2 = 15
net.ipv4.tcp_rfc1337 = 0
net.ipv4.tcp_rmem = 4096 131072 6291456
net.ipv4.tcp_sack = 1
net.ipv4.tcp_shrink_window = 0
net.ipv4.tcp_slow_start_after_idle = 1
net.ipv4.tcp_stdurg = 0
net.ipv4.tcp_syn_linear_timeouts = 4
net.ipv4.tcp_syn_retries = 6
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_thin_linear_timeouts = 0
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_tso_rtt_log = 9
net.ipv4.tcp_tso_win_divisor = 3
net.ipv4.tcp_tw_reuse = 2
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_wmem = 4096 16384 4194304
net.ipv4.tcp_workaround_signed_windows = 0
net.ipv4.udp_child_hash_entries = 0
net.ipv4.udp_early_demux = 1
net.ipv4.udp_hash_entries = 512
net.ipv4.udp_l3mdev_accept = 0
net.ipv4.udp_mem = 21570 28763 43140
net.ipv4.udp_rmem_min = 4096
net.ipv4.udp_wmem_min = 4096
net.ipv4.xfrm4_gc_thresh = 32768
net.ipv6.anycast_src_echo_reply = 0
net.ipv6.auto_flowlabels = 1
net.ipv6.bindv6only = 0
net.ipv6.conf.all.accept_dad = 0
net.ipv6.conf.all.accept_ra = 1
net.ipv6.conf.all.accept_ra_defrtr = 1
net.ipv6.conf.all.accept_ra_from_local = 0
net.ipv6.conf.all.accept_ra_min_hop_limit = 1
net.ipv6.conf.all.accept_ra_min_lft = 0
net.ipv6.conf.all.accept_ra_mtu = 1
net.ipv6.conf.all.accept_ra_pinfo = 1
net.ipv6.conf.all.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.all.accept_ra_rt_info_min_plen = 0
net.ipv6.conf.all.accept_ra_rtr_pref = 1
net.ipv6.conf.all.accept_redirects = 1
net.ipv6.conf.all.accept_source_route = 0
net.ipv6.conf.all.accept_untracked_na = 0
net.ipv6.conf.all.addr_gen_mode = 0
net.ipv6.conf.all.autoconf = 1
net.ipv6.conf.all.dad_transmits = 1
net.ipv6.conf.all.disable_ipv6 = 0
net.ipv6.conf.all.disable_policy = 0
net.ipv6.conf.all.drop_unicast_in_l2_multicast = 0
net.ipv6.conf.all.drop_unsolicited_na = 0
net.ipv6.conf.all.enhanced_dad = 1
net.ipv6.conf.all.force_mld_version = 0
net.ipv6.conf.all.force_tllao = 0
net.ipv6.conf.all.forwarding = 0
net.ipv6.conf.all.hop_limit = 64
net.ipv6.conf.all.ignore_routes_with_linkdown = 0
net.ipv6.conf.all.ioam6_enabled = 0
net.ipv6.conf.all.ioam6_id = 65535
net.ipv6.conf.all.ioam6_id_wide = 4294967295
net.ipv6.conf.all.keep_addr_on_down = 0
net.ipv6.conf.all.max_addresses = 16
net.ipv6.conf.all.max_desync_factor = 600
net.ipv6.conf.all.mc_forwarding = 0
net.ipv6.conf.all.mldv1_unsolicited_report_interval = 10000
net.ipv6.conf.all.mldv2_unsolicited_report_interval = 1000
net.ipv6.conf.all.mtu = 1280
net.ipv6.conf.all.ndisc_evict_nocarrier = 1
net.ipv6.conf.all.ndisc_notify = 0
net.ipv6.conf.all.ndisc_tclass = 0
net.ipv6.conf.all.proxy_ndp = 0
net.ipv6.conf.all.ra_defrtr_metric = 1024
net.ipv6.conf.all.regen_max_retry = 3
net.ipv6.conf.all.router_probe_interval = 60
net.ipv6.conf.all.router_solicitation_delay = 1
net.ipv6.conf.all.router_solicitation_interval = 4
net.ipv6.conf.all.router_solicitation_max_interval = 3600
net.ipv6.conf.all.router_solicitations = -1
net.ipv6.conf.all.rpl_seg_enabled = 0
net.ipv6.conf.all.seg6_enabled = 0
net.ipv6.conf.all.suppress_frag_ndisc = 1
net.ipv6.conf.all.temp_prefered_lft = 86400
net.ipv6.conf.all.temp_valid_lft = 604800
net.ipv6.conf.all.use_oif_addrs_only = 0
net.ipv6.conf.all.use_tempaddr = 0
net.ipv6.conf.default.accept_dad = 1
net.ipv6.conf.default.accept_ra = 1
net.ipv6.conf.default.accept_ra_defrtr = 1
net.ipv6.conf.default.accept_ra_from_local = 0
net.ipv6.conf.default.accept_ra_min_hop_limit = 1
net.ipv6.conf.default.accept_ra_min_lft = 0
net.ipv6.conf.default.accept_ra_mtu = 1
net.ipv6.conf.default.accept_ra_pinfo = 1
net.ipv6.conf.default.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.default.accept_ra_rt_info_min_plen = 0
net.ipv6.conf.default.accept_ra_rtr_pref = 1
net.ipv6.conf.default.accept_redirects = 1
net.ipv6.conf.default.accept_source_route = 0
net.ipv6.conf.default.accept_untracked_na = 0
net.ipv6.conf.default.addr_gen_mode = 0
net.ipv6.conf.default.autoconf = 1
net.ipv6.conf.default.dad_transmits = 1
net.ipv6.conf.default.disable_ipv6 = 0
net.ipv6.conf.default.disable_policy = 0
net.ipv6.conf.default.drop_unicast_in_l2_multicast = 0
net.ipv6.conf.default.drop_unsolicited_na = 0
net.ipv6.conf.default.enhanced_dad = 1
net.ipv6.conf.default.force_mld_version = 0
net.ipv6.conf.default.force_tllao = 0
net.ipv6.conf.default.forwarding = 0
net.ipv6.conf.default.hop_limit = 64
net.ipv6.conf.default.ignore_routes_with_linkdown = 0
net.ipv6.conf.default.ioam6_enabled = 0
net.ipv6.conf.default.ioam6_id = 65535
net.ipv6.conf.default.ioam6_id_wide = 4294967295
net.ipv6.conf.default.keep_addr_on_down = 0
net.ipv6.conf.default.max_addresses = 16
net.ipv6.conf.default.max_desync_factor = 600
net.ipv6.conf.default.mc_forwarding = 0
net.ipv6.conf.default.mldv1_unsolicited_report_interval = 10000
net.ipv6.conf.default.mldv2_unsolicited_report_interval = 1000
net.ipv6.conf.default.mtu = 1280
net.ipv6.conf.default.ndisc_evict_nocarrier = 1
net.ipv6.conf.default.ndisc_notify = 0
net.ipv6.conf.default.ndisc_tclass = 0
net.ipv6.conf.default.proxy_ndp = 0
net.ipv6.conf.default.ra_defrtr_metric = 1024
net.ipv6.conf.default.regen_max_retry = 3
net.ipv6.conf.default.router_probe_interval = 60
net.ipv6.conf.default.router_solicitation_delay = 1
net.ipv6.conf.default.router_solicitation_interval = 4
net.ipv6.conf.default.router_solicitation_max_interval = 3600
net.ipv6.conf.default.router_solicitations = -1
net.ipv6.conf.default.rpl_seg_enabled = 0
net.ipv6.conf.default.seg6_enabled = 0
net.ipv6.conf.default.suppress_frag_ndisc = 1
net.ipv6.conf.default.temp_prefered_lft = 86400
net.ipv6.conf.default.temp_valid_lft = 604800
net.ipv6.conf.default.use_oif_addrs_only = 0
net.ipv6.conf.default.use_tempaddr = 0
net.ipv6.conf.eth0.accept_dad = 1
net.ipv6.conf.eth0.accept_ra = 0
net.ipv6.conf.eth0.accept_ra_defrtr = 1
net.ipv6.conf.eth0.accept_ra_from_local = 0
net.ipv6.conf.eth0.accept_ra_min_hop_limit = 1
net.ipv6.conf.eth0.accept_ra_min_lft = 0
net.ipv6.conf.eth0.accept_ra_mtu = 1
net.ipv6.conf.eth0.accept_ra_pinfo = 1
net.ipv6.conf.eth0.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.eth0.accept_ra_rt_info_min_plen = 0
net.ipv6.conf.eth0.accept_ra_rtr_pref = 1
net.ipv6.conf.eth0.accept_redirects = 1
net.ipv6.conf.eth0.accept_source_route = 0
net.ipv6.conf.eth0.accept_untracked_na = 0
net.ipv6.conf.eth0.addr_gen_mode = 1
net.ipv6.conf.eth0.autoconf = 1
net.ipv6.conf.eth0.dad_transmits = 1
net.ipv6.conf.eth0.disable_ipv6 = 0
net.ipv6.conf.eth0.disable_policy = 0
net.ipv6.conf.eth0.drop_unicast_in_l2_multicast = 0
net.ipv6.conf.eth0.drop_unsolicited_na = 0
net.ipv6.conf.eth0.enhanced_dad = 1
net.ipv6.conf.eth0.force_mld_version = 0
net.ipv6.conf.eth0.force_tllao = 0
net.ipv6.conf.eth0.forwarding = 0
net.ipv6.conf.eth0.hop_limit = 64
net.ipv6.conf.eth0.ignore_routes_with_linkdown = 0
net.ipv6.conf.eth0.ioam6_enabled = 0
net.ipv6.conf.eth0.ioam6_id = 65535
net.ipv6.conf.eth0.ioam6_id_wide = 4294967295
net.ipv6.conf.eth0.keep_addr_on_down = 0
net.ipv6.conf.eth0.max_addresses = 16
net.ipv6.conf.eth0.max_desync_factor = 600
net.ipv6.conf.eth0.mc_forwarding = 0
net.ipv6.conf.eth0.mldv1_unsolicited_report_interval = 10000
net.ipv6.conf.eth0.mldv2_unsolicited_report_interval = 1000
net.ipv6.conf.eth0.mtu = 1500
net.ipv6.conf.eth0.ndisc_evict_nocarrier = 1
net.ipv6.conf.eth0.ndisc_notify = 0
net.ipv6.conf.eth0.ndisc_tclass = 0
net.ipv6.conf.eth0.proxy_ndp = 0
net.ipv6.conf.eth0.ra_defrtr_metric = 1024
net.ipv6.conf.eth0.regen_max_retry = 3
net.ipv6.conf.eth0.router_probe_interval = 60
net.ipv6.conf.eth0.router_solicitation_delay = 1
net.ipv6.conf.eth0.router_solicitation_interval = 4
net.ipv6.conf.eth0.router_solicitation_max_interval = 3600
net.ipv6.conf.eth0.router_solicitations = -1
net.ipv6.conf.eth0.rpl_seg_enabled = 0
net.ipv6.conf.eth0.seg6_enabled = 0
net.ipv6.conf.eth0.suppress_frag_ndisc = 1
net.ipv6.conf.eth0.temp_prefered_lft = 86400
net.ipv6.conf.eth0.temp_valid_lft = 604800
net.ipv6.conf.eth0.use_oif_addrs_only = 0
net.ipv6.conf.eth0.use_tempaddr = 0
net.ipv6.conf.lo.accept_dad = -1
net.ipv6.conf.lo.accept_ra = 1
net.ipv6.conf.lo.accept_ra_defrtr = 1
net.ipv6.conf.lo.accept_ra_from_local = 0
net.ipv6.conf.lo.accept_ra_min_hop_limit = 1
net.ipv6.conf.lo.accept_ra_min_lft = 0
net.ipv6.conf.lo.accept_ra_mtu = 1
net.ipv6.conf.lo.accept_ra_pinfo = 1
net.ipv6.conf.lo.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.lo.accept_ra_rt_info_min_plen = 0
net.ipv6.conf.lo.accept_ra_rtr_pref = 1
net.ipv6.conf.lo.accept_redirects = 1
net.ipv6.conf.lo.accept_source_route = 0
net.ipv6.conf.lo.accept_untracked_na = 0
net.ipv6.conf.lo.addr_gen_mode = 0
net.ipv6.conf.lo.autoconf = 1
net.ipv6.conf.lo.dad_transmits = 1
net.ipv6.conf.lo.disable_ipv6 = 0
net.ipv6.conf.lo.disable_policy = 0
net.ipv6.conf.lo.drop_unicast_in_l2_multicast = 0
net.ipv6.conf.lo.drop_unsolicited_na = 0
net.ipv6.conf.lo.enhanced_dad = 1
net.ipv6.conf.lo.force_mld_version = 0
net.ipv6.conf.lo.force_tllao = 0
net.ipv6.conf.lo.forwarding = 0
net.ipv6.conf.lo.hop_limit = 64
net.ipv6.conf.lo.ignore_routes_with_linkdown = 0
net.ipv6.conf.lo.ioam6_enabled = 0
net.ipv6.conf.lo.ioam6_id = 65535
net.ipv6.conf.lo.ioam6_id_wide = 4294967295
net.ipv6.conf.lo.keep_addr_on_down = 0
net.ipv6.conf.lo.max_addresses = 16
net.ipv6.conf.lo.max_desync_factor = 600
net.ipv6.conf.lo.mc_forwarding = 0
net.ipv6.conf.lo.mldv1_unsolicited_report_interval = 10000
net.ipv6.conf.lo.mldv2_unsolicited_report_interval = 1000
net.ipv6.conf.lo.mtu = 65536
net.ipv6.conf.lo.ndisc_evict_nocarrier = 1
net.ipv6.conf.lo.ndisc_notify = 0
net.ipv6.conf.lo.ndisc_tclass = 0
net.ipv6.conf.lo.proxy_ndp = 0
net.ipv6.conf.lo.ra_defrtr_metric = 1024
net.ipv6.conf.lo.regen_max_retry = 3
net.ipv6.conf.lo.router_probe_interval = 60
net.ipv6.conf.lo.router_solicitation_delay = 1
net.ipv6.conf.lo.router_solicitation_interval = 4
net.ipv6.conf.lo.router_solicitation_max_interval = 3600
net.ipv6.conf.lo.router_solicitations = -1
net.ipv6.conf.lo.rpl_seg_enabled = 0
net.ipv6.conf.lo.seg6_enabled = 0
net.ipv6.conf.lo.suppress_frag_ndisc = 1
net.ipv6.conf.lo.temp_prefered_lft = 86400
net.ipv6.conf.lo.temp_valid_lft = 604800
net.ipv6.conf.lo.use_oif_addrs_only = 0
net.ipv6.conf.lo.use_tempaddr = -1
net.ipv6.conf.wlan0.accept_dad = 1
net.ipv6.conf.wlan0.accept_ra = 0
net.ipv6.conf.wlan0.accept_ra_defrtr = 1
net.ipv6.conf.wlan0.accept_ra_from_local = 0
net.ipv6.conf.wlan0.accept_ra_min_hop_limit = 1
net.ipv6.conf.wlan0.accept_ra_min_lft = 0
net.ipv6.conf.wlan0.accept_ra_mtu = 1
net.ipv6.conf.wlan0.accept_ra_pinfo = 1
net.ipv6.conf.wlan0.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.wlan0.accept_ra_rt_info_min_plen = 0
net.ipv6.conf.wlan0.accept_ra_rtr_pref = 1
net.ipv6.conf.wlan0.accept_redirects = 1
net.ipv6.conf.wlan0.accept_source_route = 0
net.ipv6.conf.wlan0.accept_untracked_na = 0
net.ipv6.conf.wlan0.addr_gen_mode = 1
net.ipv6.conf.wlan0.autoconf = 1
net.ipv6.conf.wlan0.dad_transmits = 1
net.ipv6.conf.wlan0.disable_ipv6 = 0
net.ipv6.conf.wlan0.disable_policy = 0
net.ipv6.conf.wlan0.drop_unicast_in_l2_multicast = 0
net.ipv6.conf.wlan0.drop_unsolicited_na = 0
net.ipv6.conf.wlan0.enhanced_dad = 1
net.ipv6.conf.wlan0.force_mld_version = 0
net.ipv6.conf.wlan0.force_tllao = 0
net.ipv6.conf.wlan0.forwarding = 0
net.ipv6.conf.wlan0.hop_limit = 64
net.ipv6.conf.wlan0.ignore_routes_with_linkdown = 0
net.ipv6.conf.wlan0.ioam6_enabled = 0
net.ipv6.conf.wlan0.ioam6_id = 65535
net.ipv6.conf.wlan0.ioam6_id_wide = 4294967295
net.ipv6.conf.wlan0.keep_addr_on_down = 0
net.ipv6.conf.wlan0.max_addresses = 16
net.ipv6.conf.wlan0.max_desync_factor = 600
net.ipv6.conf.wlan0.mc_forwarding = 0
net.ipv6.conf.wlan0.mldv1_unsolicited_report_interval = 10000
net.ipv6.conf.wlan0.mldv2_unsolicited_report_interval = 1000
net.ipv6.conf.wlan0.mtu = 1500
net.ipv6.conf.wlan0.ndisc_evict_nocarrier = 1
net.ipv6.conf.wlan0.ndisc_notify = 0
net.ipv6.conf.wlan0.ndisc_tclass = 0
net.ipv6.conf.wlan0.proxy_ndp = 0
net.ipv6.conf.wlan0.ra_defrtr_metric = 1024
net.ipv6.conf.wlan0.regen_max_retry = 3
net.ipv6.conf.wlan0.router_probe_interval = 60
net.ipv6.conf.wlan0.router_solicitation_delay = 1
net.ipv6.conf.wlan0.router_solicitation_interval = 4
net.ipv6.conf.wlan0.router_solicitation_max_interval = 3600
net.ipv6.conf.wlan0.router_solicitations = -1
net.ipv6.conf.wlan0.rpl_seg_enabled = 0
net.ipv6.conf.wlan0.seg6_enabled = 0
net.ipv6.conf.wlan0.suppress_frag_ndisc = 1
net.ipv6.conf.wlan0.temp_prefered_lft = 86400
net.ipv6.conf.wlan0.temp_valid_lft = 604800
net.ipv6.conf.wlan0.use_oif_addrs_only = 0
net.ipv6.conf.wlan0.use_tempaddr = 0
net.ipv6.fib_multipath_hash_fields = 7
net.ipv6.fib_multipath_hash_policy = 0
net.ipv6.fib_notify_on_flag_change = 0
net.ipv6.flowlabel_consistency = 1
net.ipv6.flowlabel_reflect = 0
net.ipv6.flowlabel_state_ranges = 0
net.ipv6.fwmark_reflect = 0
net.ipv6.icmp.echo_ignore_all = 0
net.ipv6.icmp.echo_ignore_anycast = 0
net.ipv6.icmp.echo_ignore_multicast = 0
net.ipv6.icmp.error_anycast_as_unicast = 0
net.ipv6.icmp.ratelimit = 1000
net.ipv6.icmp.ratemask = 0-1,3-127
net.ipv6.idgen_delay = 1
net.ipv6.idgen_retries = 3
net.ipv6.ioam6_id = 16777215
net.ipv6.ioam6_id_wide = 4294967295 16777215
net.ipv6.ip6frag_high_thresh = 4194304
net.ipv6.ip6frag_low_thresh = 3145728
net.ipv6.ip6frag_secret_interval = 0
net.ipv6.ip6frag_time = 60
net.ipv6.ip_nonlocal_bind = 0
net.ipv6.max_dst_opts_length = 2147483647
net.ipv6.max_dst_opts_number = 8
net.ipv6.max_hbh_length = 2147483647
net.ipv6.max_hbh_opts_number = 8
net.ipv6.mld_max_msf = 64
net.ipv6.mld_qrv = 2
net.ipv6.neigh.default.anycast_delay = 100
net.ipv6.neigh.default.app_solicit = 0
net.ipv6.neigh.default.base_reachable_time_ms = 30000
net.ipv6.neigh.default.delay_first_probe_time = 5
net.ipv6.neigh.default.gc_interval = 30
net.ipv6.neigh.default.gc_stale_time = 60
net.ipv6.neigh.default.gc_thresh1 = 128
net.ipv6.neigh.default.gc_thresh2 = 512
net.ipv6.neigh.default.gc_thresh3 = 1024
net.ipv6.neigh.default.interval_probe_time_ms = 5000
net.ipv6.neigh.default.locktime = 0
net.ipv6.neigh.default.mcast_resolicit = 0
net.ipv6.neigh.default.mcast_solicit = 3
net.ipv6.neigh.default.proxy_delay = 80
net.ipv6.neigh.default.proxy_qlen = 64
net.ipv6.neigh.default.retrans_time_ms = 1000
net.ipv6.neigh.default.ucast_solicit = 3
net.ipv6.neigh.default.unres_qlen = 91
net.ipv6.neigh.default.unres_qlen_bytes = 180224
net.ipv6.neigh.eth0.anycast_delay = 100
net.ipv6.neigh.eth0.app_solicit = 0
net.ipv6.neigh.eth0.base_reachable_time_ms = 30000
net.ipv6.neigh.eth0.delay_first_probe_time = 5
net.ipv6.neigh.eth0.gc_stale_time = 60
net.ipv6.neigh.eth0.interval_probe_time_ms = 5000
net.ipv6.neigh.eth0.locktime = 0
net.ipv6.neigh.eth0.mcast_resolicit = 0
net.ipv6.neigh.eth0.mcast_solicit = 3
net.ipv6.neigh.eth0.proxy_delay = 80
net.ipv6.neigh.eth0.proxy_qlen = 64
net.ipv6.neigh.eth0.retrans_time_ms = 1000
net.ipv6.neigh.eth0.ucast_solicit = 3
net.ipv6.neigh.eth0.unres_qlen = 91
net.ipv6.neigh.eth0.unres_qlen_bytes = 180224
net.ipv6.neigh.lo.anycast_delay = 100
net.ipv6.neigh.lo.app_solicit = 0
net.ipv6.neigh.lo.base_reachable_time_ms = 30000
net.ipv6.neigh.lo.delay_first_probe_time = 5
net.ipv6.neigh.lo.gc_stale_time = 60
net.ipv6.neigh.lo.interval_probe_time_ms = 5000
net.ipv6.neigh.lo.locktime = 0
net.ipv6.neigh.lo.mcast_resolicit = 0
net.ipv6.neigh.lo.mcast_solicit = 3
net.ipv6.neigh.lo.proxy_delay = 80
net.ipv6.neigh.lo.proxy_qlen = 64
net.ipv6.neigh.lo.retrans_time_ms = 1000
net.ipv6.neigh.lo.ucast_solicit = 3
net.ipv6.neigh.lo.unres_qlen = 91
net.ipv6.neigh.lo.unres_qlen_bytes = 180224
net.ipv6.neigh.wlan0.anycast_delay = 100
net.ipv6.neigh.wlan0.app_solicit = 0
net.ipv6.neigh.wlan0.base_reachable_time_ms = 30000
net.ipv6.neigh.wlan0.delay_first_probe_time = 5
net.ipv6.neigh.wlan0.gc_stale_time = 60
net.ipv6.neigh.wlan0.interval_probe_time_ms = 5000
net.ipv6.neigh.wlan0.locktime = 0
net.ipv6.neigh.wlan0.mcast_resolicit = 0
net.ipv6.neigh.wlan0.mcast_solicit = 3
net.ipv6.neigh.wlan0.proxy_delay = 80
net.ipv6.neigh.wlan0.proxy_qlen = 64
net.ipv6.neigh.wlan0.retrans_time_ms = 1000
net.ipv6.neigh.wlan0.ucast_solicit = 3
net.ipv6.neigh.wlan0.unres_qlen = 91
net.ipv6.neigh.wlan0.unres_qlen_bytes = 180224
net.ipv6.route.gc_elasticity = 9
net.ipv6.route.gc_interval = 30
net.ipv6.route.gc_min_interval = 0
net.ipv6.route.gc_min_interval_ms = 500
net.ipv6.route.gc_thresh = 1024
net.ipv6.route.gc_timeout = 60
net.ipv6.route.max_size = 2147483647
net.ipv6.route.min_adv_mss = 1220
net.ipv6.route.mtu_expires = 600
net.ipv6.route.skip_notify_on_dev_down = 0
net.ipv6.seg6_flowlabel = 0
net.ipv6.xfrm6_gc_thresh = 32768
net.netfilter.nf_hooks_lwtunnel = 0
net.netfilter.nf_log.0 = NONE
net.netfilter.nf_log.1 = NONE
net.netfilter.nf_log.10 = 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_all_netns = 0
net.unix.max_dgram_qlen = 512
sunrpc.max_resvport = 1023
sunrpc.min_resvport = 665
sunrpc.tcp_fin_timeout = 15
sunrpc.tcp_max_slot_table_entries = 65536
sunrpc.tcp_slot_table_entries = 2
sunrpc.udp_slot_table_entries = 16
user.max_cgroup_namespaces = 5187
user.max_fanotify_groups = 128
user.max_fanotify_marks = 11375
user.max_inotify_instances = 128
user.max_inotify_watches = 10582
user.max_ipc_namespaces = 5187
user.max_mnt_namespaces = 5187
user.max_net_namespaces = 5187
user.max_pid_namespaces = 5187
user.max_time_namespaces = 5187
user.max_user_namespaces = 5187
user.max_uts_namespaces = 5187
vm.admin_reserve_kbytes = 8192
vm.compact_unevictable_allowed = 1
vm.compaction_proactiveness = 20
vm.dirty_background_bytes = 0
vm.dirty_background_ratio = 10
vm.dirty_bytes = 0
vm.dirty_expire_centisecs = 3000
vm.dirty_ratio = 20
vm.dirty_writeback_centisecs = 500
vm.dirtytime_expire_seconds = 43200
vm.extfrag_threshold = 500
vm.laptop_mode = 0
vm.legacy_va_layout = 0
vm.lowmem_reserve_ratio = 256 32 0
vm.max_map_count = 65530
vm.memfd_noexec = 0
vm.min_free_kbytes = 16384
vm.mmap_min_addr = 4096
vm.mmap_rnd_bits = 8
vm.oom_dump_tasks = 1
vm.oom_kill_allocating_task = 0
vm.overcommit_kbytes = 0
vm.overcommit_memory = 0
vm.overcommit_ratio = 50
vm.page-cluster = 3
vm.page_lock_unfairness = 5
vm.panic_on_oom = 0
vm.percpu_pagelist_high_fraction = 0
vm.stat_interval = 1
vm.swappiness = 60
vm.user_reserve_kbytes = 28751
vm.vfs_cache_pressure = 100
vm.watermark_boost_factor = 15000
vm.watermark_scale_factor = 10パターン③：/etc/sysctl.confの確認
最後のパターンは「/etc/sysctl.conf」の確認です。
「/etc/sysctl.conf」は、「/proc/sys」ディレクトリ配下に存在するファイルの初期値を設定する際に利用します。
これは、パターン①で先述した通り、「proc/sys」ディレクトリ配下のファイルを「echoコマンド」による変更を行なった場合、LinuxサーバのOff/Onや再起動により初期値に戻ることを防ぐためです。
そのため、最初の状態では何も記載されていないため、全てコメントアウトになっています。
/etc/sysctl.confの初期状態（Debian）
daimaru@raspi-test:~ $ sudo cat /etc/sysctl.conf
#
# /etc/sysctl.conf - Configuration file for setting system variables
# See /etc/sysctl.d/ for additional system variables.
# See sysctl.conf (5) for information.
#
#kernel.domainname = example.com
# Uncomment the following to stop low-level messages on console
#kernel.printk = 3 4 1 3
###################################################################
# Functions previously found in netbase
#
# Uncomment the next two lines to enable Spoof protection (reverse-path filter)
# Turn on Source Address Verification in all interfaces to
# prevent some spoofing attacks
#net.ipv4.conf.default.rp_filter=1
#net.ipv4.conf.all.rp_filter=1
# Uncomment the next line to enable TCP/IP SYN cookies
# See http://lwn.net/Articles/277146/
# Note: This may impact IPv6 TCP sessions too
#net.ipv4.tcp_syncookies=1
# Uncomment the next line to enable packet forwarding for IPv4
#net.ipv4.ip_forward=1
# Uncomment the next line to enable packet forwarding for IPv6
# Enabling this option disables Stateless Address Autoconfiguration
# based on Router Advertisements for this host
#net.ipv6.conf.all.forwarding=1
###################################################################
# Additional settings - these settings can improve the network
# security of the host and prevent against some network attacks
# including spoofing attacks and man in the middle attacks through
# redirection. Some network environments, however, require that these
# settings are disabled so review and enable them as needed.
#
# Do not accept ICMP redirects (prevent MITM attacks)
#net.ipv4.conf.all.accept_redirects = 0
#net.ipv6.conf.all.accept_redirects = 0
# _or_
# Accept ICMP redirects only for gateways listed in our default
# gateway list (enabled by default)
# net.ipv4.conf.all.secure_redirects = 1
#
# Do not send ICMP redirects (we are not a router)
#net.ipv4.conf.all.send_redirects = 0
#
# Do not accept IP source route packets (we are not a router)
#net.ipv4.conf.all.accept_source_route = 0
#net.ipv6.conf.all.accept_source_route = 0
#
# Log Martian Packets
#net.ipv4.conf.all.log_martians = 1
#
###################################################################
# Magic system request Key
# 0=disable, 1=enable all, >1 bitmask of sysrq functions
# See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html
# for what other values do
#kernel.sysrq=438次節で紹介するhostname変更による動作確認で詳細は触れていきます。
IPv4のforward設定変更による動作確認
ここまでカーネルパラメータの確認方法や変更方法を簡単にまとめてみました。
次は実際に変更・確認方法の動作確認をしていきたいと思います。
「/proc/sys/net/ipv4/ip_forward」の中身をechoコマンドによる変更した際の動作と/etc/sysctl.confの変更による動作を確認していきます。
root@raspi-test:~# cat /proc/sys/net/ipv4/ip_forward
0
root@raspi-test:~# echo "1" > /proc/sys/net/ipv4/ip_forward
root@raspi-test:~# cat /proc/sys/net/ipv4/ip_forward
1この状態で再起動後の状態を確認してみましょう。
root@raspi-test:~# cat /proc/sys/net/ipv4/ip_forward
0上記の結果より、「1」に設定していたはずが「0」に戻っています。
ここで、sysctl.confの中身を変更した後に「sysctl -p」コマンドによる変更の動作で確認してみましょう。
root@raspi-test:~# vim /etc/sysctl.conf
root@raspi-test:~# sysctl -p
net.ipv4.ip_forward = 1
root@raspi-test:~# sysctl -n net.ipv4.ip_forward
1上記設定後、再起動を実施してみるとしっかり反映されていることがわかります。
カーネルパラメータを変更する際はこの方法で変更すればOKです。
root@raspi-test:~# sysctl -n net.ipv4.ip_forward
1
最後に
今回はカーネルの基本部分を簡単にまとめてみました。
可能な限り記事を簡潔にすることで細切れの時間でも理解できるようにしていきたいと思います。
