divertctrl: 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/sbin/divertctrl - from package: isdnutils-base

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

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