linux内核防synflood

转贴：

前两天服务器给人搞了一把，查到这个配置，打开内核的syncookies 还是有用的

sysctl -a | grep syn 看到：

QUOTE:

net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_syncookies = 0
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_syn_retries = 5

修改为：

QUOTE:

sysctl -w net.ipv4.tcp_max_syn_backlog=2048
sysctl -w net.ipv4.tcp_syncookies=1
sysctl -w net.ipv4.tcp_synack_retries=3
sysctl -w net.ipv4.tcp_syn_retries=3