# https://wiki.khnet.info/index.php/Conntrack_tuning

kernel.pid_max = 65536
kernel.randomize_va_space = 1

net.core.wmem_max = 8388608
net.core.rmem_max = 8388608

net.ipv4.tcp_synack_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 2048

net.ipv4.tcp_wmem = 4096 87380 8388608
net.ipv4.tcp_rmem = 4096 87380 8388608

net.ipv4.neigh.default.gc_thresh1 = 512
net.ipv4.neigh.default.gc_thresh2 = 1024
net.ipv4.neigh.default.gc_thresh3 = 6144

net.netfilter.nf_conntrack_expect_max = 4096
net.netfilter.nf_conntrack_generic_timeout = 600
net.netfilter.nf_conntrack_icmp_timeout = 10
net.netfilter.nf_conntrack_max = 8388608
net.netfilter.nf_conntrack_tcp_be_liberal = 0
net.netfilter.nf_conntrack_tcp_loose = 1
net.netfilter.nf_conntrack_tcp_max_retrans = 3
net.netfilter.nf_conntrack_tcp_timeout_close = 10
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 10
net.netfilter.nf_conntrack_tcp_timeout_established = 86400
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 10
net.netfilter.nf_conntrack_tcp_timeout_last_ack = 10
net.netfilter.nf_conntrack_tcp_timeout_max_retrans = 300
net.netfilter.nf_conntrack_tcp_timeout_syn_recv = 5
net.netfilter.nf_conntrack_tcp_timeout_syn_sent = 5
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 10
net.netfilter.nf_conntrack_udp_timeout = 10
net.netfilter.nf_conntrack_udp_timeout_stream = 180

net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.log_martians = 0
net.ipv4.conf.all.arp_filter = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1

net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.default.log_martians = 0
net.ipv4.conf.default.arp_filter = 1
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.default.arp_ignore = 1

net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1

net.ipv6.conf.default.accept_redirects = 0
net.ipv6.conf.default.accept_source_route = 0

net.ipv4.ip_forward = 1

# ipt-netflow
net.netflow.active_timeout = 300