atmarp: 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/atmarp - from package: atm-tools

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

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