ping で即応答が得られるサーバーの生死確認
ping 192.168.10.1 -w 1 -c 1
ローカル（イントラ）ならほとんどの場合これで応答得られますね。 0% パケットロスならOKです。
たとえば１３台に一斉にPING出すには
for i in {1..13};
do
echo debian`printf %02d $i` ;
ping debian`printf %02d $i` -w 1 -c 1 | grep 0% ;
done;
実行結果
debian01 1 packets transmitted, 1 received, 0% packet loss, time 0ms #これは生きてる debian02 1 packets transmitted, 0 received, 100% packet loss, time 0ms #ココ以降は死んでる。停電対応 debian03 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian04 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian05 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian06 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian07 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian08 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian09 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian10 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian11 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian12 1 packets transmitted, 0 received, 100% packet loss, time 0ms debian13 1 packets transmitted, 0 received, 100% packet loss, time 0ms
