http://blog.lifeibo.com/?p=380

1.sysctl

sysctl命令被用于在内核运行时动态地修改内核的运行参数,可用的内核参数在目录/proc/sys中

[root@server1 ~]# cd /proc/sys
[root@server1 sys]# ll
总用量 0
dr-xr-xr-x 0 root root 0 6月 5 20:59 abi
dr-xr-xr-x 0 root root 0 6月 5 20:59 crypto
dr-xr-xr-x 0 root root 0 6月 5 21:03 debug
dr-xr-xr-x 0 root root 0 6月 5 21:03 dev
dr-xr-xr-x 0 root root 0 5月 16 08:23 fs
dr-xr-xr-x 0 root root 0 6月 5 21:03 kernel
dr-xr-xr-x 0 root root 0 6月 5 20:59 net
dr-xr-xr-x 0 root root 0 6月 5 21:03 vm

sysctl命令的配置文件是/etc/sysctl.conf,可以
1.使用sysctl工具修改内核参数
2.直接修改/etc/sysctl.conf net.ipv4.tcp_rmem 用来配置读缓冲的大小,三个值,第一个是这个读缓冲的最小值,第三个是最大值,中间的是默认值。我们可以在程序中修改读缓冲的大小,但是不能超过最小与最大。为了使每个socket所使用的内存数最小,我这里设置默认值为4096。
net.ipv4.tcp_wmem 用来配置写缓冲的大小。
读缓冲与写缓冲在大小,直接影响到socket在内核中内存的占用。
net.ipv4.tcp_mem则是配置tcp的内存大小,其单位是页,而不是字节。当超过第二个值时,TCP进入pressure模式,此时TCP尝试稳定其内存的使用,当小于第一个值时,就退出pressure模式。当内存占用超过第三个值时,TCP就拒绝分配socket了,查看dmesg,会打出很多的日志“TCP: too many of orphaned sockets”。
另外net.ipv4.tcp_max_orphans这个值也要设置一下,这个值表示系统所能处理不属于任何进程的socket数量,当我们需要快速建立大量连接时,就需要关注下这个值了。当不属于任何进程的socket的数量大于这个值时,dmesg就会看到”too many of orphaned sockets”。
----------------------------------------------------------------------------------------------------------------------

[root@server1 sys]# cat /etc/sysctl.conf
# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.


# Controls IP packet forwarding
net.ipv4.ip_forward = 0


# Controls source route verification


# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0


# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0


# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1


# Controls the use of TCP syncookies


# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0


# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536


# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536


# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736


# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296


vm.swappiness = 0
net.ipv4.neigh.default.gc_stale_time=120
net.ipv4.conf.all.rp_filter=0
net.ipv4.conf.default.rp_filter=0
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.all.arp_announce=2
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_synack_retries = 2
net.ipv4.conf.lo.arp_announce=2

--------------------------------------------------------------------------

.使用格式

sysctl [options] parameters
常用的选项:
[html] view plain copy 在CODE上查看代码片派生到我的代码片
-w #当改变sysctl设置时使用此项
-p #加载指定的配置文件中的内核参数,默认是/etc/sysctl.conf
-a #打印当前所有可用的内核参数变量和值
-A #以表格方式打印当前所有可用的内核参数变量和值

[root@server1 sys]# sysctl
usage: sysctl [-n] [-e] variable ...
sysctl [-n] [-e] [-q] -w variable=value ...
sysctl [-n] [-e] -a
sysctl [-n] [-e] [-q] -p <file> (default /etc/sysctl.conf)
sysctl [-n] [-e] -A

.常用操作举例

()查看所有可读变量
sysctl -a
()修改的是内存中的主机名
sysctl kernel.hostname=testhost

[root@server1 ~]# sysctl -a
kernel.sched_child_runs_first = 0
kernel.sched_min_granularity_ns = 1000000
kernel.sched_latency_ns = 5000000
kernel.sched_wakeup_granularity_ns = 1000000
kernel.sched_tunable_scaling = 1
kernel.sched_features = 3183
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_enabled = 1
kernel.stack_tracer_enabled = 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 = 15597
kernel.random.poolsize = 4096
kernel.random.entropy_avail = 3501
kernel.random.read_wakeup_threshold = 64
kernel.random.write_wakeup_threshold = 128
kernel.random.boot_id = bff341bb-ea1e-41fa-b71d-92700d922e4f
kernel.random.uuid = 838d4d16-6c65-4cc8-8d9d-992177307713
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.watchdog = 1
kernel.watchdog_thresh = 60
kernel.softlockup_panic = 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 = 12
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 = 4194304
kernel.hung_task_timeout_secs = 120
kernel.hung_task_warnings = 10
kernel.compat-log = 1
kernel.max_lock_depth = 1024
kernel.poweroff_cmd = /sbin/poweroff
kernel.keys.maxkeys = 200
kernel.keys.maxbytes = 20000
kernel.keys.root_maxkeys = 200
kernel.keys.root_maxbytes = 20000
kernel.keys.gc_delay = 300
kernel.slow-work.min-threads = 2
kernel.slow-work.max-threads = 15
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.vsyscall64 = 1
kernel.ostype = Linux
kernel.osrelease = 2.6.32-431.23.3.el6.x86_64
kernel.version = #1 SMP Thu Jul 31 17:20:51 UTC 2014
kernel.hostname = server1
kernel.domainname = (none)
kernel.shmmax = 68719476736
kernel.shmall = 4294967296
kernel.shmmni = 4096
kernel.shm_rmid_forced = 0
kernel.msgmax = 65536
kernel.msgmni = 1982
kernel.msgmnb = 65536
kernel.sem = 250 32000 32 128
kernel.auto_msgmni = 1
kernel.pty.max = 4096
kernel.pty.nr = 78
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.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 = 0
vm.nr_hugepages = 0
vm.nr_hugepages_mempolicy = 0
vm.hugetlb_shm_group = 0
vm.hugepages_treat_as_movable = 0
vm.nr_overcommit_hugepages = 0
vm.lowmem_reserve_ratio = 256 256 32
vm.drop_caches = 0
vm.min_free_kbytes = 45056
vm.extra_free_kbytes = 0
vm.unmap_area_factor = 0
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.zone_reclaim_mode = 0
vm.min_unmapped_ratio = 1
vm.min_slab_ratio = 5
vm.stat_interval = 1
vm.mmap_min_addr = 4096
vm.numa_zonelist_order = default
vm.scan_unevictable_pages = 0
vm.memory_failure_early_kill = 0
vm.memory_failure_recovery = 1
fs.inode-nr = 6386 17
fs.inode-state = 6386 17 0 0 0 0 0
fs.file-nr = 512 0 98566
fs.file-max = 98566
fs.nr_open = 1048576
fs.dentry-state = 6321 1206 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 = 2661
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 = 204431
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.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 = 124928
net.core.rmem_max = 124928
net.core.wmem_default = 124928
net.core.rmem_default = 124928
net.core.dev_weight = 64
net.core.netdev_max_backlog = 1000
net.core.message_cost = 5
net.core.message_burst = 10
net.core.optmem_max = 20480
net.core.rps_sock_flow_entries = 0
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 = 120
net.ipv4.neigh.default.unres_qlen = 0
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 = 0
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 = 0
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.neigh.eth1.mcast_solicit = 3
net.ipv4.neigh.eth1.ucast_solicit = 3
net.ipv4.neigh.eth1.app_solicit = 0
net.ipv4.neigh.eth1.retrans_time = 99
net.ipv4.neigh.eth1.base_reachable_time = 30
net.ipv4.neigh.eth1.delay_first_probe_time = 5
net.ipv4.neigh.eth1.gc_stale_time = 60
net.ipv4.neigh.eth1.unres_qlen = 0
net.ipv4.neigh.eth1.proxy_qlen = 64
net.ipv4.neigh.eth1.anycast_delay = 99
net.ipv4.neigh.eth1.proxy_delay = 79
net.ipv4.neigh.eth1.locktime = 99
net.ipv4.neigh.eth1.retrans_time_ms = 1000
net.ipv4.neigh.eth1.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_no_pmtu_disc = 0
net.ipv4.ip_nonlocal_bind = 0
net.ipv4.tcp_syn_retries = 5
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_max_orphans = 65536
net.ipv4.tcp_max_tw_buckets = 5000
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 = 1024
net.ipv4.ip_local_port_range = 32768 61000
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 = 93504 124672 187008
net.ipv4.tcp_wmem = 4096 16384 3989504
net.ipv4.tcp_rmem = 4096 87380 3989504
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 = 131072
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 = 93504 124672 187008
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 = 2
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 = 0
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 = 2
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 = 0
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 = 2
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 = 0
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 = 2
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.conf.eth1.forwarding = 0
net.ipv4.conf.eth1.mc_forwarding = 0
net.ipv4.conf.eth1.accept_redirects = 1
net.ipv4.conf.eth1.secure_redirects = 1
net.ipv4.conf.eth1.shared_media = 1
net.ipv4.conf.eth1.rp_filter = 0
net.ipv4.conf.eth1.send_redirects = 1
net.ipv4.conf.eth1.accept_source_route = 0
net.ipv4.conf.eth1.src_valid_mark = 0
net.ipv4.conf.eth1.proxy_arp = 0
net.ipv4.conf.eth1.medium_id = 0
net.ipv4.conf.eth1.bootp_relay = 0
net.ipv4.conf.eth1.log_martians = 0
net.ipv4.conf.eth1.tag = 0
net.ipv4.conf.eth1.arp_filter = 0
net.ipv4.conf.eth1.arp_announce = 2
net.ipv4.conf.eth1.arp_ignore = 0
net.ipv4.conf.eth1.arp_accept = 0
net.ipv4.conf.eth1.arp_notify = 0
net.ipv4.conf.eth1.proxy_arp_pvlan = 0
net.ipv4.conf.eth1.disable_xfrm = 0
net.ipv4.conf.eth1.disable_policy = 0
net.ipv4.conf.eth1.force_igmp_version = 0
net.ipv4.conf.eth1.promote_secondaries = 0
net.ipv4.conf.eth1.accept_local = 0
net.ipv4.conf.eth1.route_localnet = 0
net.ipv4.ip_forward = 0
net.ipv4.xfrm4_gc_thresh = 262144
net.ipv4.ipfrag_high_thresh = 262144
net.ipv4.ipfrag_low_thresh = 196608
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.ipfrag_secret_interval = 600
net.ipv4.ipfrag_max_dist = 64
net.unix.max_dgram_qlen = 10
abi.vsyscall32 = 1
crypto.fips_enabled = 0

LINUX系统全部参数 sysctl -a + 网络参数设置的更多相关文章

  1. Linux系统Web网站目录和文件安全权限设置

    查看Linux文件的权限:ls -l 文件名称查看linux文件夹的权限:ls -ld 文件夹名称(所在目录)例如: drwxr-xr-x 2 root root 4096 2009-01-14 17 ...

  2. 在Linux系统下远程连接oracle的防火墙设置

    在Linux系统要远程连接Oracle的防火墙设置方法: 打开5801至5810 端口用于vnc iptables -I INPUT -p tcp --dport 5801:5810 -j ACCEP ...

  3. linux系统中重启网卡后网络不通(NetworkManager篇)

    一.故障现象 RHEL7.6系统,使用nmcli绑定双网卡后,再使用以下命令重启network服务后主机网络异常,导致无法通过ssh远程登录系统. # systemctl restart networ ...

  4. GNU Linux系统变量(sysctl配置命令)综合使用

    查看全部kernel变量的值 sysctl -a 怎样查看一个系统变量的值 1).cat /proc/sys/net/ipv4/ip_local_port_range 32768 61000 2).s ...

  5. Linux 系统下10个查看网络与监听的命令

    下面列出来的10个基础的每个linux用户都应该知道的网络和监控命令.网络和监控命令类似于这些: hostname, ping, ifconfig, iwconfig, netstat, nslook ...

  6. Linux 系统自动备份数据库及定时任务的设置

    首先想到数据库的自动备份,由于涉及业务原因需要在每天固定的时间去调用方法执行备份.如果不考虑业务要求,只考虑实现的话可以通过Linux系统提供的定时任务去完成备份操作. 本文讲的就是利用Linux系统 ...

  7. linux系统下Vi编辑器或者Vim编辑器设置显示行号、自动缩进、调整tab键宽度的技巧?

    工作中嫌vim 中一个tab键的宽度太大,linux系统默认,没改之前是一个tab键宽度是8个字符,想改成4个字符, 操作如下:(注意:这是在root用户下)cd ~vim .vimrc添加如下几行: ...

  8. Linux系统——PXE高效能批量网络装机

    PXE:Pre-boot Excution Environment,预启动执行环境,石油Intel公司开发的网络引导技术,工作在Client.Server模式,允许客户机通过网络从远程服务器下载阴道镜 ...

  9. Broadcom网卡linux系统下无法连接到网络问题(某种情况- -||)的解决办法

    国际惯例,先闲扯: 其实我是个电脑白痴,至于为什么一个电脑白痴会来做开发呢?原因非常匪夷所思且简单--“因为做开发看起来很酷!”,那为什么要一把年纪了才来做开发呢?原因更简单,“当我回过神,就发现我已 ...

随机推荐

  1. python 重载 __hash__ __eq__

    __author__ = 'root' from urlparse import urlparse class host_news(): def __init__(self, id, url): se ...

  2. webservice 的权限验证

    1. http://blog.csdn.net/jaune161/article/details/25602655 2. http://wcp88888888.iteye.com/blog/13993 ...

  3. python面向对象高级编程

    正常情况下,当我们定义了一个class,创建了一个class的实例后,我们可以给该实例绑定任何属性和方法,这就是动态语言的灵活性.先定义class: >>> class Studen ...

  4. Codeforces Round #197 (Div. 2) : B

    也是水题一个,不过稍微要细心点.... 贴代码: #include<iostream> using namespace std; long long n,m; ; int main() { ...

  5. [转贴]关于C++的抽象的一点新认识

    http://my.oschina.net/fzyz999/blog/138491 关于本文 本文是笔者在阅读<C++沉思录>第0章——序幕后的一点想法,可以算作是笔记也可以算作是读后感. ...

  6. Ubuntu下安装Qt4.5(包括X86和ARM版本)

    条件:TQ2440开发板,虚拟机安装的Ubuntu10.04,安装好天嵌自带的GCC交叉编译器参考:http://blog.csdn.net/newnewman80/article/details/6 ...

  7. 公告: 新博客已经迁移到 www.root.run

    root.run www.root.run www.root.run/sitemap.html www.root.run/sitemap.xml

  8. python统计英文首字母出现的次数

    使用python解析有道词典导出的xml格式单词,统计各个首字母出现的次数,并按次数由多到少进行排序 相关实现 导出的xml格式如下 <wordbook> <item> < ...

  9. 使用Systrace分析UI性能

    开发应用的时候,应该检查它是否有流畅的用户体验,即60fps的帧率.如果由于某种原因丢帧,我们首先要做的就是知道系统在做什么(造成丢帧的原因). Systrace允许你监视和跟踪Android系统的行 ...

  10. JS 日期操作类

    /* 日期对象格式化为指定日期格式 */Date.prototype.format = function (format) { var o = { "M+": this.getMo ...