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! 如果槼則庫通過了這個數據包，本次會話被添加狀態檢測表中。所有後續的包都會和狀態檢測表比較而被通過。 返回 pingable