ipsort: 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/ipsort - from package: pnscan

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

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