mknic-nbi: 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/mknic-nbi - from package: drbl

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

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