debian-edu-update-netblock: command not found

Have You tried accessing the binary with the full path?

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/debian-edu-update-netblock - from package: debian-edu-config

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