netconvert: 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/netconvert - from package: sumo

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

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