iptables-restore: 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:

/sbin/iptables-restore - from package: iptables

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

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