fping -a参数为什么显示ping不通的信息

fping -a -f ./ip_list.txt 为什么会显示ping不通的信息 ， 如下所示

10.4.31.61

10.4.31.56

10.4.31.79

10.4.31.73

10.4.31.26

10.4.31.55

10.4.31.37

10.4.31.81

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.39

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.27

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.22

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.24

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.86

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.85

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.84

ICMP Host Unreachable from 10.4.31.231 for ICMP Echo sent to 10.4.31.83