rarpd: 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/rarpd - from package: rarpd

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

On Debian possible default full paths are:

/usr/sbin/rarpd - from package: rarpd

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

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