测试结果，要求pc_3可以ping同pc_5,pc_4可以ping同pc_6
pc_3 ping pc_5
pc_3 ping pc_4
pc_3 ping pc_6
Ping 192.168.1.5 (192.168.1.5): 56 data bytes, press CTRL_C to break
56 bytes from 192.168.1.5: icmp_seq=0 ttl=255 time=1.649 ms
56 bytes from 192.168.1.5: icmp_seq=1 ttl=255 time=0.971 ms
56 bytes from 192.168.1.5: icmp_seq=2 ttl=255 time=0.968 ms
56 bytes from 192.168.1.5: icmp_seq=3 ttl=255 time=0.872 ms
56 bytes from 192.168.1.5: icmp_seq=4 ttl=255 time=0.878 ms
--- Ping statistics for 192.168.1.5 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss
round-trip min/avg/max/std-dev = 0.872/1.068/1.649/0.294 ms
\
^
% Unrecognized command found at '^' position.
Ping 192.168.1.4 (192.168.1.4): 56 data bytes, press CTRL_C to break
Request time out
Request time out
Request time out
Request time out
Request time out
--- Ping statistics for 192.168.1.4 ---
5 packet(s) transmitted, 0 packet(s) received, 100.0% packet loss
Ping 192.168.1.6 (192.168.1.6): 56 data bytes, press CTRL_C to break
Request time out
Request time out
Request time out
Request time out
Request time out
--- Ping statistics for 192.168.1.6 ---
5 packet(s) transmitted, 0 packet(s) received, 100.0% packet loss
Inactive timeout reached, logging out.