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.ipv6.conf.all.disable_ipv6 = 1

net.ipv6.conf.default.disable_ipv6 = 1

net.ipv6.conf.lo.disable_ipv6 = 1

net.ipv4.conf.lo.arp_announce=2

centos 7 阿里默认优化