dibbler-relay: 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 CentOS possible default full paths are:

/usr/sbin/dibbler-relay - from package: dibbler-relay

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/dibbler-relay - from package: dibbler-relay

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

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