Ingress filtering is an example of static filters.Rules in egress filtering are set manually by network administrators in against spoofed source IP addresses (Ferguson and Senie,1998).

• 入口过滤是静态过滤的一个例子，出口过滤中的规则由网络管理员手动设置以防御源IP地址欺骗(FergusonandSenie,1998)。