sysctl -w  net.netfilter.nf_log.0 = NONE
sysctl -w  net.netfilter.nf_log.1 = NONE
sysctl -w  net.netfilter.nf_log.2 = NONE
sysctl -w  net.netfilter.nf_log.3 = NONE
sysctl -w  net.netfilter.nf_log.4 = NONE
sysctl -w  net.netfilter.nf_log.5 = NONE
sysctl -w  net.netfilter.nf_log.6 = NONE
sysctl -w  net.netfilter.nf_log.7 = NONE
sysctl -w  net.netfilter.nf_log.8 = NONE
sysctl -w  net.netfilter.nf_log.9 = NONE
sysctl -w  net.netfilter.nf_log.10 = NONE
sysctl -w  net.netfilter.nf_log.11 = NONE
sysctl -w  net.netfilter.nf_log.12 = NONE
sysctl -w  net.core.somaxconn = 128
sysctl -w  net.core.xfrm_aevent_etime = 10
sysctl -w  net.core.xfrm_aevent_rseqth = 2
sysctl -w  net.core.xfrm_larval_drop = 1
sysctl -w  net.core.xfrm_acq_expires = 30
sysctl -w  net.core.wmem_max = 124928
sysctl -w  net.core.rmem_max = 124928
sysctl -w  net.core.wmem_default = 124928
sysctl -w  net.core.rmem_default = 124928
sysctl -w  net.core.dev_weight = 64
sysctl -w  net.core.netdev_max_backlog = 1000
sysctl -w  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
sysctl -w  net.core.message_cost = 5
sysctl -w  net.core.message_burst = 10
sysctl -w  net.core.optmem_max = 20480
sysctl -w  net.core.rps_sock_flow_entries = 0
sysctl -w  net.core.busy_poll = 0
sysctl -w  net.core.busy_read = 0
sysctl -w  net.core.netdev_budget = 300
sysctl -w  net.core.warnings = 1
sysctl -w  net.ipv4.route.gc_thresh = 262144
sysctl -w  net.ipv4.route.max_size = 4194304
sysctl -w  net.ipv4.route.gc_min_interval = 0
sysctl -w  net.ipv4.route.gc_min_interval_ms = 500
sysctl -w  net.ipv4.route.gc_timeout = 300
sysctl -w  net.ipv4.route.gc_interval = 60
sysctl -w  net.ipv4.route.redirect_load = 20
sysctl -w  net.ipv4.route.redirect_number = 9
sysctl -w  net.ipv4.route.redirect_silence = 20480
sysctl -w  net.ipv4.route.error_cost = 1000
sysctl -w  net.ipv4.route.error_burst = 5000
sysctl -w  net.ipv4.route.gc_elasticity = 8
sysctl -w  net.ipv4.route.mtu_expires = 600
sysctl -w  net.ipv4.route.min_pmtu = 552
sysctl -w  net.ipv4.route.min_adv_mss = 256
sysctl -w  net.ipv4.route.secret_interval = 600
sysctl -w  net.ipv4.neigh.default.mcast_solicit = 3
sysctl -w  net.ipv4.neigh.default.ucast_solicit = 3
sysctl -w  net.ipv4.neigh.default.app_solicit = 0
sysctl -w  net.ipv4.neigh.default.retrans_time = 99
sysctl -w  net.ipv4.neigh.default.base_reachable_time = 30
sysctl -w  net.ipv4.neigh.default.delay_first_probe_time = 5
sysctl -w  net.ipv4.neigh.default.gc_stale_time = 120
sysctl -w  net.ipv4.neigh.default.unres_qlen = 3
sysctl -w  net.ipv4.neigh.default.proxy_qlen = 64
sysctl -w  net.ipv4.neigh.default.anycast_delay = 99
sysctl -w  net.ipv4.neigh.default.proxy_delay = 79
sysctl -w  net.ipv4.neigh.default.locktime = 99
sysctl -w  net.ipv4.neigh.default.retrans_time_ms = 1000
sysctl -w  net.ipv4.neigh.default.base_reachable_time_ms = 30000
sysctl -w  net.ipv4.neigh.default.gc_interval = 30
sysctl -w  net.ipv4.neigh.default.gc_thresh1 = 128
sysctl -w  net.ipv4.neigh.default.gc_thresh2 = 512
sysctl -w  net.ipv4.neigh.default.gc_thresh3 = 1024
sysctl -w  net.ipv4.neigh.lo.mcast_solicit = 3
sysctl -w  net.ipv4.neigh.lo.ucast_solicit = 3
sysctl -w  net.ipv4.neigh.lo.app_solicit = 0
sysctl -w  net.ipv4.neigh.lo.retrans_time = 99
sysctl -w  net.ipv4.neigh.lo.base_reachable_time = 30
sysctl -w  net.ipv4.neigh.lo.delay_first_probe_time = 5
sysctl -w  net.ipv4.neigh.lo.gc_stale_time = 60
sysctl -w  net.ipv4.neigh.lo.unres_qlen = 3
sysctl -w  net.ipv4.neigh.lo.proxy_qlen = 64
sysctl -w  net.ipv4.neigh.lo.anycast_delay = 99
sysctl -w  net.ipv4.neigh.lo.proxy_delay = 79
sysctl -w  net.ipv4.neigh.lo.locktime = 99
sysctl -w  net.ipv4.neigh.lo.retrans_time_ms = 1000
sysctl -w  net.ipv4.neigh.lo.base_reachable_time_ms = 30000
sysctl -w  net.ipv4.neigh.eth0.mcast_solicit = 3
sysctl -w  net.ipv4.neigh.eth0.ucast_solicit = 3
sysctl -w  net.ipv4.neigh.eth0.app_solicit = 0
sysctl -w  net.ipv4.neigh.eth0.retrans_time = 99
sysctl -w  net.ipv4.neigh.eth0.base_reachable_time = 30
sysctl -w  net.ipv4.neigh.eth0.delay_first_probe_time = 5
sysctl -w  net.ipv4.neigh.eth0.gc_stale_time = 120
sysctl -w  net.ipv4.neigh.eth0.unres_qlen = 3
sysctl -w  net.ipv4.neigh.eth0.proxy_qlen = 64
sysctl -w  net.ipv4.neigh.eth0.anycast_delay = 99
sysctl -w  net.ipv4.neigh.eth0.proxy_delay = 79
sysctl -w  net.ipv4.neigh.eth0.locktime = 99
sysctl -w  net.ipv4.neigh.eth0.retrans_time_ms = 1000
sysctl -w  net.ipv4.neigh.eth0.base_reachable_time_ms = 30000
sysctl -w  net.ipv4.tcp_timestamps = 1
#缺省值为1
#Timestamps 用在其它一些东西中﹐可以防范那些伪造的 sequence 号码。一条1G的宽带线路或许会重遇到带 out-of-line数值的旧sequence 号码(假如它是由于上次产生的)。Timestamp 会让它知道这是个 '旧封包'。(该文件表示是否启用以一种比超时重发更精确的方法（RFC 1323）来启用对 RTT 的计算；为了实现更好的性能应该启用这个选项。)

sysctl -w  net.ipv4.tcp_window_scaling = 1
#缺省值为1
#该文件表示设置tcp/ip会话的滑动窗口大小是否可变。参数值为布尔值，为1时表示可变，为0时表示不可变。tcp/ip通常使用的窗口最大可达到 65535 字节，对于高速网络，该值可能太小，这时候如果启用了该功能，可以使tcp/ip滑动窗口大小增大数个数量级，从而提高数据传输的能力(RFC 1323)。（对普通地百M网络而言，关闭会降低开销，所以如果不是高速网络，可以考虑设置为0）

sysctl -w  net.ipv4.tcp_sack = 1
#缺省值为1
#使用 Selective ACK﹐它可以用来查找特定的遗失的数据报--- 因此有助于快速恢复状态。该文件表示是否启用有选择的应答（Selective Acknowledgment），这可以通过有选择地应答乱序接收到的报文来提高性能（这样可以让发送者只发送丢失的报文段）。(对于广域网通信来说这个选项应该启用，但是这会增加对 CPU 的占用。)

sysctl -w  net.ipv4.tcp_retrans_collapse = 1
#缺省值为1
#对于某些有bug的打印机提供针对其bug的兼容性。(一般不需要这个支持,可以关闭它)
 
sysctl -w  net.ipv4.ip_default_ttl = 64
sysctl -w  net.ipv4.ip_nonlocal_bind = 0
sysctl -w  net.ipv4.tcp_syn_retries = 5
#对于一个新建连接，内核要发送多少个 SYN 连接请求才决定放弃。不应该大于255，默认值是5，对应于180秒左右时间。(对于大负载而物理通信良好的网络而言,这个值偏高,可修改为2.这个值仅仅是针对对外的连接,对进来的连接,是由tcp_retries1 决定的)

sysctl -w  net.ipv4.tcp_synack_retries = 2
#对于远端的连接请求SYN，内核会发送SYN ＋ ACK数据报，以确认收到上一个 SYN连接请求包。这是所谓的三次握手( threeway handshake)机制的第二个步骤。这里决定内核在放弃连接之前所送出的 SYN+ACK 数目。不应该大于255，默认值是5，对应于180秒左右时间。(可以根据上面的tcp_syn_retries来决定这个值)

sysctl -w  net.ipv4.tcp_max_orphans = 262144
#缺省值是8192
#系统所能处理不属于任何进程的TCP sockets最大数量。假如超过这个数量﹐那么不属于任何进程的连接会被立即reset，并同时显示警告信息。之所以要设定这个限制﹐纯粹为了抵御那些简单的 DoS 攻击﹐千万不要依赖这个或是人为的降低这个限制(这个值Redhat AS版本中设置为32768,但是很多防火墙修改的时候,建议该值修改为2000)
 
sysctl -w  net.ipv4.tcp_max_tw_buckets = 5000
#默认值是180000
#系统在同时所处理的最大 timewait sockets 数目。如果超过此数的话﹐time-wait socket 会被立即砍除并且显示警告信息。之所以要设定这个限制﹐纯粹为了抵御那些简单的 DoS 攻击﹐千万不要人为的降低这个限制﹐不过﹐如果网络条件需要比默认值更多﹐则可以提高它(或许还要增加内存)。(事实上做NAT的时候最好可以适当地增加该值)

sysctl -w  net.ipv4.ip_dynaddr = 0
sysctl -w  net.ipv4.tcp_keepalive_time = 7200
#当keepalive打开的情况下，TCP发送keepalive消息的频率。(由于目前网络攻击等因素,造成了利用这个进行的攻击很频繁,曾经也有cu的朋友提到过,说如果2边建立了连接,然后不发送任何数据或者rst/fin消息,那么持续的时间是不是就是2小时,空连接攻击?tcp_keepalive_time就是预防此情形的.我个人在做nat服务的时候的修改值为1800秒)

sysctl -w  net.ipv4.tcp_keepalive_probes = 9
#TCP发送keepalive探测以确定该连接已经断开的次数。(注意:保持连接仅在SO_KEEPALIVE套接字选项被打开是才发送.次数默认不需要修改,当然根据情形也可以适当地缩短此值.设置为5比较合适)

sysctl -w  net.ipv4.tcp_keepalive_intvl = 75
#探测消息发送的频率，乘以tcp_keepalive_probes就得到对于从开始探测以来没有响应的连接杀除的时间。默认值为75秒，也就是没有活动的连接将在大约11分钟以后将被丢弃。(对于普通应用来说,这个值有一些偏大,可以根据需要改小.特别是web类服务器需要改小该值,15是个比较合适的值)

sysctl -w  net.ipv4.tcp_retries1 = 3
#放弃回应一个TCP连接请求前﹐需要进行多少次重试。RFC 规定最低的数值是3﹐这也是默认值﹐根据RTO的值大约在3秒 - 8分钟之间。(注意:这个值同时还决定进入的syn连接)

sysctl -w  net.ipv4.tcp_retries2 = 15
#在丢弃激活(已建立通讯状况)的TCP连接之前﹐需要进行多少次重试。默认值为15，根据RTO的值来决定，相当于13-30分钟(RFC1122规定，必须大于100秒).(这个值根据目前的网络设置,可以适当地改小,我的网络内修改为了5)

sysctl -w  net.ipv4.tcp_fin_timeout = 60
sysctl -w  net.ipv4.tcp_syncookies = 1
#默认值是0
#只有在内核编译时选择了CONFIG_SYNCOOKIES时才会发生作用。当出现syn等候队列出现溢出时象对方发送syncookies。目的是为了防止syn flood攻击。
#注意：该选项千万不能用于那些没有收到攻击的高负载服务器，如果在日志中出现synflood消息，但是调查发现没有收到synflood攻击，而是合法用户的连接负载过高的原因，你应该调整其它参数来提高服务器性能。参考:
sysctl -w  tcp_max_syn_backlog
sysctl -w  tcp_synack_retries
sysctl -w  tcp_abort_on_overflow
sysctl -w  syncookie严重的违背TCP协议，不允许使用TCP扩展，可能对某些服务导致严重的性能影响(如SMTP转发)。(注意,该实现与BSD上面使用的tcp proxy一样,是违反了RFC中关于tcp连接的三次握手实现的,但是对于防御syn-flood的确很有用.)
sysctl -w  net.ipv4.tcp_tw_recycle = 0
#默认值是0
#打开快速 TIME-WAIT sockets 回收。除非得到技术专家的建议或要求﹐请不要随意修改这个值。(做NAT的时候，建议打开它)

sysctl -w  net.ipv4.tcp_abort_on_overflow = 0
#缺省值是0
#当守护进程太忙而不能接受新的连接，就象对方发送reset消息，默认值是false。这意味着当溢出的原因是因为一个偶然的猝发，那么连接将恢复状态。只有在你确信守护进程真的不能完成连接请求时才打开该选项，该选项会影响客户的使用。(对待已经满载的sendmail,apache这类服务的时候,这个可以很快让客户端终止连接,可以给予服务程序处理已有连接的缓冲机会,所以很多防火墙上推荐打开它)

sysctl -w  net.ipv4.tcp_stdurg = 0
#默认值为0
#使用 TCP urg pointer 字段中的主机请求解释功能。大部份的主机都使用老旧的 BSD解释，因此如果您在 Linux 打开它﹐或会导致不能和它们正确沟通。

sysctl -w  net.ipv4.tcp_rfc1337 = 0
#缺省值为0
#这个开关可以启动对于在RFC1337中描述的"tcp 的time-wait暗杀危机"问题的修复。启用后，内核将丢弃那些发往time-wait状态TCP套接字的RST 包.

sysctl -w  net.ipv4.tcp_max_syn_backlog = 1024
#对于那些依然还未获得客户端确认的连接请求﹐需要保存在队列中最大数目。对于超过 128Mb 内存的系统﹐默认值是1024 ﹐低于 128Mb 的则为 128。如果服务器经常出现过载﹐可以尝试增加这个数字。警告﹗假如您将此值设为大于1024﹐最好修改 include/net/tcp.h 里面的 TCP_SYNQ_HSIZE ﹐以保持TCP_SYNQ_HSIZE*16<=tcp_max_syn_backlog ﹐并且编进核心之内。(SYN Flood攻击利用TCP协议散布握手的缺陷，伪造虚假源IP地址发送大量TCP-SYN半打开连接到目标系统，最终导致目标系统Socket队列资源耗尽而无法接受新的连接。为了应付这种攻击，现代Unix系统中普遍采用多连接队列处理的方式来缓冲(而不是解决)这种攻击，是用一个基本队列处理正常的完全连接应用(Connect()和Accept() )，是用另一个队列单独存放半打开连接。这种双队列处理方式和其他一些系统内核措施(例如Syn-Cookies/Caches)联合应用时，能够比较有效的缓解小规模的SYN Flood攻击(事实证明<1000p/s)加大SYN队列长度可以容纳更多等待连接的网络连接数，所以对Server来说可以考虑增大该值.)

sysctl -w  net.ipv4.ip_local_port_range = 32768    61000
sysctl -w  net.ipv4.ip_local_reserved_ports =
sysctl -w  net.ipv4.igmp_max_memberships = 20
sysctl -w  net.ipv4.igmp_max_msf = 10
sysctl -w  net.ipv4.inet_peer_threshold = 65664
sysctl -w  net.ipv4.inet_peer_minttl = 120
sysctl -w  net.ipv4.inet_peer_maxttl = 600
sysctl -w  net.ipv4.inet_peer_gc_mintime = 10
sysctl -w  net.ipv4.inet_peer_gc_maxtime = 120
sysctl -w  net.ipv4.tcp_orphan_retries = 0
#在近端丢弃TCP连接之前﹐要进行多少次重试。默认值是7个﹐相当于 50秒 - 16分钟﹐视 RTO 而定。如果您的系统是负载很大的web服务器﹐那么也许需要降低该值﹐这类 sockets 可能会耗费大量的资源。另外参的考tcp_max_orphans 。(事实上做NAT的时候,降低该值也是好处显著的,我本人的网络环境中降低该值为3)

sysctl -w  net.ipv4.tcp_fack = 1
#缺省值为1
#打开FACK拥塞避免和快速重传功能。(注意，当tcp_sack设置为0的时候，这个值即使设置为1也无效)

sysctl -w  net.ipv4.tcp_reordering = 3
#默认值是3
#TCP流中重排序的数据报最大数量 。 (一般有看到推荐把这个数值略微调整大一些,比如5)

sysctl -w  net.ipv4.tcp_ecn = 2
#缺省值为0
#打开TCP的直接拥塞通告功能。

sysctl -w  net.ipv4.tcp_dsack = 1
#缺省值为1
#允许TCP发送"两个完全相同"的SACK。

sysctl -w  net.ipv4.tcp_mem = 753600    1004800    1507200
#tcp_mem(3个INTEGER变量)：low, pressure, high
#low：当TCP使用了低于该值的内存页面数时，TCP不会考虑释放内存。(理想情况下，这个值应与指定给 tcp_wmem 的第 2 个值相匹配 - 这第 2 个值表明，最大页面大小乘以最大并发请求数除以页大小 (131072 * 300 / 4096)。 )
#pressure：当TCP使用了超过该值的内存页面数量时，TCP试图稳定其内存使用，进入pressure模式，当内存消耗低于low值时则退出pressure状态。(理想情况下这个值应该是 TCP 可以使用的总缓冲区大小的最大值 (204800 * 300 / 4096)。 )
#high：允许所有tcp sockets用于排队缓冲数据报的页面量。(如果超过这个值，TCP 连接将被拒绝，这就是为什么不要令其过于保守 (512000 * 300 / 4096) 的原因了。 在这种情况下，提供的价值很大，它能处理很多连接，是所预期的 2.5 倍；或者使现有连接能够传输 2.5 倍的数据。 我的网络里为192000 300000 732000)
#一般情况下这些值是在系统启动时根据系统内存数量计算得到的。

sysctl -w  net.ipv4.tcp_wmem = 4096    16384    4194304
#tcp_wmem(3个INTEGER变量)： min, default, max
#min：为TCP socket预留用于发送缓冲的内存最小值。每个tcp socket都可以在建议以后都可以使用它。默认值为4096(4K)。
#default：为TCP socket预留用于发送缓冲的内存数量，默认情况下该值会影响其它协议使用的net.core.wmem_default 值，一般要低于net.core.wmem_default的值。默认值为16384(16K)。
#max: 用于TCP socket发送缓冲的内存最大值。该值不会影响net.core.wmem_max，"静态"选择参数SO_SNDBUF则不受该值影响。默认值为131072(128K)。（对于服务器而言，增加这个参数的值对于发送数据很有帮助,在我的网络环境中,修改为了51200 131072 204800）

sysctl -w  net.ipv4.tcp_rmem = 4096    87380    4194304
#cp_rmem (3个INTEGER变量)： min, default, max
#min：为TCP socket预留用于接收缓冲的内存数量，即使在内存出现紧张情况下tcp socket都至少会有这么多数量的内存用于接收缓冲，默认值为8K。
#default：为TCP socket预留用于接收缓冲的内存数量，默认情况下该值影响其它协议使用的net.core.wmem_default 值。该值决定了在tcp_adv_win_scale、tcp_app_win和tcp_app_win=0默认值情况下，TCP窗口大小为65535。默认值为87380
#max：用于TCP socket接收缓冲的内存最大值。该值不会影响 net.core.wmem_max，"静态"选择参数 SO_SNDBUF则不受该值影响。默认值为 128K。默认值为87380*2 bytes。（可以看出，.max的设置最好是default的两倍,对于NAT来说主要该增加它,我的网络里为 51200 131072 204800）

sysctl -w  net.ipv4.tcp_app_win = 31
#默认值是31
#保留max(window/2^tcp_app_win, mss)数量的窗口由于应用缓冲。当为0时表示不需要缓冲。

sysctl -w  net.ipv4.tcp_adv_win_scale = 2
#默认值为2
#计算缓冲开销bytes/2^tcp_adv_win_scale(如果tcp_adv_win_scale > 0)或者bytes-bytes/2^(-tcp_adv_win_scale)(如果tcp_adv_win_scale <= 0）。
sysctl -w  net.ipv4.tcp_tw_reuse = 0
#默认值是0
#该文件表示是否允许重新应用处于TIME-WAIT状态的socket用于新的TCP连接(这个对快速重启动某些服务,而启动后提示端口已经被使用的情形非常有帮助)

sysctl -w  net.ipv4.tcp_frto = 2
sysctl -w  net.ipv4.tcp_frto_response = 0
sysctl -w  net.ipv4.tcp_low_latency = 0
#缺省值为0
#允许 TCP/IP 栈适应在高吞吐量情况下低延时的情况；这个选项一般情形是的禁用。(但在构建Beowulf 集群的时候,打开它很有帮助)
sysctl -w  
sysctl -w  net.ipv4.tcp_no_metrics_save = 0
sysctl -w  net.ipv4.tcp_moderate_rcvbuf = 1
sysctl -w  net.ipv4.tcp_tso_win_divisor = 3
sysctl -w  net.ipv4.tcp_congestion_control = cubic
sysctl -w  net.ipv4.tcp_abc = 0
sysctl -w  net.ipv4.tcp_mtu_probing = 0
sysctl -w  net.ipv4.tcp_base_mss = 512
sysctl -w  net.ipv4.tcp_workaround_signed_windows = 0
sysctl -w  net.ipv4.tcp_challenge_ack_limit = 100
sysctl -w  net.ipv4.tcp_limit_output_bytes = 262144
sysctl -w  net.ipv4.tcp_dma_copybreak = 4096
sysctl -w  net.ipv4.tcp_slow_start_after_idle = 1
sysctl -w  net.ipv4.cipso_cache_enable = 1
sysctl -w  net.ipv4.cipso_cache_bucket_size = 10
sysctl -w  net.ipv4.cipso_rbm_optfmt = 0
sysctl -w  net.ipv4.cipso_rbm_strictvalid = 1
sysctl -w  net.ipv4.tcp_available_congestion_control = cubic reno
sysctl -w  net.ipv4.tcp_allowed_congestion_control = cubic reno
sysctl -w  net.ipv4.tcp_max_ssthresh = 0
sysctl -w  net.ipv4.tcp_thin_linear_timeouts = 0
sysctl -w  net.ipv4.tcp_thin_dupack = 0
sysctl -w  net.ipv4.tcp_min_tso_segs = 2
sysctl -w  net.ipv4.udp_mem = 753600    1004800    1507200
sysctl -w  net.ipv4.udp_rmem_min = 4096
sysctl -w  net.ipv4.udp_wmem_min = 4096
sysctl -w  net.ipv4.conf.all.forwarding = 0
sysctl -w  net.ipv4.conf.all.mc_forwarding = 0
sysctl -w  net.ipv4.conf.all.accept_redirects = 1
sysctl -w  net.ipv4.conf.all.secure_redirects = 1
sysctl -w  net.ipv4.conf.all.shared_media = 1
sysctl -w  net.ipv4.conf.all.rp_filter = 0
sysctl -w  net.ipv4.conf.all.send_redirects = 1
sysctl -w  net.ipv4.conf.all.accept_source_route = 0
sysctl -w  net.ipv4.conf.all.src_valid_mark = 0
sysctl -w  net.ipv4.conf.all.proxy_arp = 0
sysctl -w  net.ipv4.conf.all.medium_id = 0
sysctl -w  net.ipv4.conf.all.bootp_relay = 0
sysctl -w  net.ipv4.conf.all.log_martians = 0
sysctl -w  net.ipv4.conf.all.tag = 0
sysctl -w  net.ipv4.conf.all.arp_filter = 0
sysctl -w  net.ipv4.conf.all.arp_announce = 2
sysctl -w  net.ipv4.conf.all.arp_ignore = 0
sysctl -w  net.ipv4.conf.all.arp_accept = 0
sysctl -w  net.ipv4.conf.all.arp_notify = 0
sysctl -w  net.ipv4.conf.all.proxy_arp_pvlan = 0
sysctl -w  net.ipv4.conf.all.disable_xfrm = 0
sysctl -w  net.ipv4.conf.all.disable_policy = 0
sysctl -w  net.ipv4.conf.all.force_igmp_version = 0
sysctl -w  net.ipv4.conf.all.promote_secondaries = 0
sysctl -w  net.ipv4.conf.all.accept_local = 0
sysctl -w  net.ipv4.conf.all.route_localnet = 0
sysctl -w  net.ipv4.conf.default.forwarding = 0
sysctl -w  net.ipv4.conf.default.mc_forwarding = 0
sysctl -w  net.ipv4.conf.default.accept_redirects = 1
sysctl -w  net.ipv4.conf.default.secure_redirects = 1
sysctl -w  net.ipv4.conf.default.shared_media = 1
sysctl -w  net.ipv4.conf.default.rp_filter = 0
sysctl -w  net.ipv4.conf.default.send_redirects = 1
sysctl -w  net.ipv4.conf.default.accept_source_route = 0
sysctl -w  net.ipv4.conf.default.src_valid_mark = 0
sysctl -w  net.ipv4.conf.default.proxy_arp = 0
sysctl -w  net.ipv4.conf.default.medium_id = 0
sysctl -w  net.ipv4.conf.default.bootp_relay = 0
sysctl -w  net.ipv4.conf.default.log_martians = 0
sysctl -w  net.ipv4.conf.default.tag = 0
sysctl -w  net.ipv4.conf.default.arp_filter = 0
sysctl -w  net.ipv4.conf.default.arp_announce = 2
sysctl -w  net.ipv4.conf.default.arp_ignore = 0
sysctl -w  net.ipv4.conf.default.arp_accept = 0
sysctl -w  net.ipv4.conf.default.arp_notify = 0
sysctl -w  net.ipv4.conf.default.proxy_arp_pvlan = 0
sysctl -w  net.ipv4.conf.default.disable_xfrm = 0
sysctl -w  net.ipv4.conf.default.disable_policy = 0
sysctl -w  net.ipv4.conf.default.force_igmp_version = 0
sysctl -w  net.ipv4.conf.default.promote_secondaries = 0
sysctl -w  net.ipv4.conf.default.accept_local = 0
sysctl -w  net.ipv4.conf.default.route_localnet = 0
sysctl -w  net.ipv4.conf.lo.forwarding = 0
sysctl -w  net.ipv4.conf.lo.mc_forwarding = 0
sysctl -w  net.ipv4.conf.lo.accept_redirects = 1
sysctl -w  net.ipv4.conf.lo.secure_redirects = 1
sysctl -w  net.ipv4.conf.lo.shared_media = 1
sysctl -w  net.ipv4.conf.lo.rp_filter = 0
sysctl -w  net.ipv4.conf.lo.send_redirects = 1
sysctl -w  net.ipv4.conf.lo.accept_source_route = 1
sysctl -w  net.ipv4.conf.lo.src_valid_mark = 0
sysctl -w  net.ipv4.conf.lo.proxy_arp = 0
sysctl -w  net.ipv4.conf.lo.medium_id = 0
sysctl -w  net.ipv4.conf.lo.bootp_relay = 0
sysctl -w  net.ipv4.conf.lo.log_martians = 0
sysctl -w  net.ipv4.conf.lo.tag = 0
sysctl -w  net.ipv4.conf.lo.arp_filter = 0
sysctl -w  net.ipv4.conf.lo.arp_announce = 2
sysctl -w  net.ipv4.conf.lo.arp_ignore = 0
sysctl -w  net.ipv4.conf.lo.arp_accept = 0
sysctl -w  net.ipv4.conf.lo.arp_notify = 0
sysctl -w  net.ipv4.conf.lo.proxy_arp_pvlan = 0
sysctl -w  net.ipv4.conf.lo.disable_xfrm = 1
sysctl -w  net.ipv4.conf.lo.disable_policy = 1
sysctl -w  net.ipv4.conf.lo.force_igmp_version = 0
sysctl -w  net.ipv4.conf.lo.promote_secondaries = 0
sysctl -w  net.ipv4.conf.lo.accept_local = 0
sysctl -w  net.ipv4.conf.lo.route_localnet = 0
sysctl -w  net.ipv4.conf.eth0.forwarding = 0
sysctl -w  net.ipv4.conf.eth0.mc_forwarding = 0
sysctl -w  net.ipv4.conf.eth0.accept_redirects = 1
sysctl -w  net.ipv4.conf.eth0.secure_redirects = 1
sysctl -w  net.ipv4.conf.eth0.shared_media = 1
sysctl -w  net.ipv4.conf.eth0.rp_filter = 0
sysctl -w  net.ipv4.conf.eth0.send_redirects = 1
sysctl -w  net.ipv4.conf.eth0.accept_source_route = 0
sysctl -w  net.ipv4.conf.eth0.src_valid_mark = 0
sysctl -w  net.ipv4.conf.eth0.proxy_arp = 0
sysctl -w  net.ipv4.conf.eth0.medium_id = 0
sysctl -w  net.ipv4.conf.eth0.bootp_relay = 0
sysctl -w  net.ipv4.conf.eth0.log_martians = 0
sysctl -w  net.ipv4.conf.eth0.tag = 0
sysctl -w  net.ipv4.conf.eth0.arp_filter = 0
sysctl -w  net.ipv4.conf.eth0.arp_announce = 2
sysctl -w  net.ipv4.conf.eth0.arp_ignore = 0
sysctl -w  net.ipv4.conf.eth0.arp_accept = 0
sysctl -w  net.ipv4.conf.eth0.arp_notify = 0
sysctl -w  net.ipv4.conf.eth0.proxy_arp_pvlan = 0
sysctl -w  net.ipv4.conf.eth0.disable_xfrm = 0
sysctl -w  net.ipv4.conf.eth0.disable_policy = 0
sysctl -w  net.ipv4.conf.eth0.force_igmp_version = 0
sysctl -w  net.ipv4.conf.eth0.promote_secondaries = 0
sysctl -w  net.ipv4.conf.eth0.accept_local = 0
sysctl -w  net.ipv4.conf.eth0.route_localnet = 0
sysctl -w  net.ipv4.ip_forward = 0
sysctl -w  net.ipv4.xfrm4_gc_thresh = 2097152
sysctl -w  net.ipv4.ipfrag_high_thresh = 4194304
sysctl -w  net.ipv4.ipfrag_low_thresh = 3145728
sysctl -w  net.ipv4.ipfrag_time = 30
sysctl -w  net.ipv4.icmp_echo_ignore_all = 0
sysctl -w  net.ipv4.icmp_echo_ignore_broadcasts = 1
sysctl -w  net.ipv4.icmp_ignore_bogus_error_responses = 1
sysctl -w  net.ipv4.icmp_errors_use_inbound_ifaddr = 0
sysctl -w  net.ipv4.icmp_ratelimit = 1000
sysctl -w  net.ipv4.icmp_ratemask = 6168
sysctl -w  net.ipv4.rt_cache_rebuild_count = 4
sysctl -w  net.ipv4.ping_group_range = 1    0
sysctl -w  net.ipv4.ip_no_pmtu_disc = 0
sysctl -w  net.ipv4.ip_forward_use_pmtu = 0
sysctl -w  net.ipv4.ipfrag_secret_interval = 600
sysctl -w  net.ipv4.ipfrag_max_dist = 64
sysctl -w  net.unix.max_dgram_qlen = 10