linux centos7.x下TCP/IP及内核参数优化调优

如下配置是写在/etc/sysctl.conf中，可使用sysctl -p生效

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

vm.swappiness = 0
net.ipv4.neigh.default.gc_stale_time=120

# see details in https://help.aliyun.com/knowledge_detail/39428.html
net.ipv4.conf.all.rp_filter=0
net.ipv4.conf.default.rp_filter=0
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_announce=2
net.ipv4.conf.all.arp_announce=2

# see details in https://help.aliyun.com/knowledge_detail/41334.html
#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
kernel.sysrq = 1

#optimize tcp
net.ipv4.tcp_keepalive_time=60
##表示当keepalive起用的时候，TCP发送keepalive消息的频度。缺省是2小时，改为120s。

net.ipv4.ip_local_port_range=1024 65000
###表示用于向外连接的端口范围。缺省情况下很小：32768到61000，改为1024到65000。

net.ipv4.tcp_