fwb_ipt: 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/fwb_ipt - from package: fwbuilder

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

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