neutron-vpn-agent: 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/neutron-vpn-agent - from package: neutron-common

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

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