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iptables -F
iptables -X
iptables -t nat -X
iptables -t nat -F
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -A FORWARD -o lo -j ACCEPT
iptables -A INPUT -j ACCEPT -m state --state ESTABLISHED,RELATED
iptables -A FORWARD -j ACCEPT -m state --state ESTABLISHED,RELATED
iptables -A OUTPUT -j ACCEPT -m state --state ESTABLISHED,RELATED

net.ipv4.ip_forward = 1
net.ipv4.ip_dynaddr = 1
net.ipv4.conf.default.rp_filter = 2
net.ipv4.conf.all.rp_filter = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.icmp_echo_ignore_all = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.ip_default_ttl = 128
net.ipv4.tcp_tw_recycle=1
net.ipv4.tcp_tw_reuse=1
net.ipv4.tcp_syncookies = 1
net.netfilter.nf_conntrack_tcp_timeout_established = 1800
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.all.secure_redirects = 1
net.ipv4.conf.default.secure_redirects = 1
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.ip_local_port_range = 32768 61569
net.ipv4.conf.net.arp_ignore = 0
net.ipv6.conf.all.disable_ipv6 = 0
net.ipv6.conf.default.disable_ipv6 = 0
net.ipv6.conf.lo.disable_ipv6 = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.tcp_syncookies = 1
net.ipv4.neigh.default.base_reachable_time = 86400
net.ipv4.neigh.default.gc_stale_time = 86400
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_moderate_rcvbuf = 1
net.core.netdev_max_backlog = 2500
net.core.rmem_default = 524288
net.core.wmem_default = 524288
net.ipv4.tcp_wmem = 4096 87380 524288
net.ipv4.tcp_rmem = 4096 87380 524288
net.ipv4.tcp_mem = 524288 524288 524288
net.core.rmem_max = 524288
net.core.wmem_max = 524288
net.ipv4.neigh.default.gc_thresh1 = 4096
net.ipv4.neigh.default.gc_thresh2 = 8192
net.ipv4.neigh.default.gc_thresh3 = 16384
net.ipv4.tcp_rfc1337 = 1
net.ipv4.ip_no_pmtu_disc = 0
net.ipv4.tcp_sack = 1
net.ipv4.tcp_fack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_ecn = 0