noping: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/noping - from package: liboping

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/noping - from package: oping

You may install the required package with command apt-get install {package}

Error in other languages:
noping: bevel nie gevind nie
noping: comandă negăsită
noping: comando não encontrado
noping: commande introuvable
noping: command not found
noping: käsku ei ole
noping: không tìm thấy lệnh
noping: komanda nerasta
noping: Kommando nicht gefunden.
noping: kommandot finns inte
noping: komut yok
noping: nie znaleziono polecenia
noping: níor aimsíodh an t-ordú
noping: no se encontró la orden
noping: no s'ha trobat l'ordre
noping: opdracht niet gevonden
noping: parancs nem található
noping: perintah tidak ditemukan
noping: príkaz nenájdený
noping: příkaz nenalezen
noping: команда не найдена
noping: командата не е открита
noping: 命令找不到
noping: コマンドが見つかりません