rmcpping: 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/sbin/rmcpping - from package: freeipmi

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

On Debian possible default full paths are:

/usr/sbin/rmcpping - from package: freeipmi-tools

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

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