rfdump: 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/rfdump - from package: rfdump

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

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