netgroup: 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 Debian possible default full paths are:

/usr/bin/netgroup - from package: ng-utils

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

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