arpaname: 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/arpaname - from package: bind

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

On Debian possible default full paths are:

/usr/sbin/arpaname - from package: bind9

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

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