As my network is gigabit and the servers are running in vmware, some of the fping return 0.00ms (which in fact the server is still alive but the network is too fast)
I edited src/zabbix_server/pinger/pinger.c
//SET_DBL_RESULT(&value, mseconds/1000);
SET_DBL_RESULT(&value, mseconds?mseconds/1000:0.0000001);
I edited src/zabbix_server/pinger/pinger.c
//SET_DBL_RESULT(&value, mseconds/1000);
SET_DBL_RESULT(&value, mseconds?mseconds/1000:0.0000001);