izattach: command not found

Have You tried accessing the binary with the full path?

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/sbin/izattach - from package: lowpan-tools

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