常见例句#define ICMP_ECHO 8 /* Echo Request */ you might allow it incoming for trusted addresses (note some NICs will require you to make your primary DNS Server pingable! 如果规则库通过了这个数据包，本次会话被添加状态检测表中。所有后续的包都会和状态检测表比较而被通过。 返回 pingable