atftp: 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/atftp - from package: atftp

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

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