named: 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/named - from package: bind

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

On Debian possible default full paths are:

/usr/sbin/named - from package: bind9

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

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