nettee: 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/nettee - from package: nettee

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

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