net: 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/bin/net - from package: samba4-common
/usr/bin/net - from package: samba-common

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

On Debian possible default full paths are:

/usr/bin/net - from package: samba-common-bin

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

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