njb-handshake: 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/bin/njb-handshake - from package: libnjb-tools

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

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