l2ping: 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/bin/l2ping - from package: bluez

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

On Debian possible default full paths are:

/usr/bin/l2ping - from package: bluez

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

Error in other languages:
l2ping: bevel nie gevind nie
l2ping: comandă negăsită
l2ping: comando não encontrado
l2ping: commande introuvable
l2ping: command not found
l2ping: käsku ei ole
l2ping: không tìm thấy lệnh
l2ping: komanda nerasta
l2ping: Kommando nicht gefunden.
l2ping: kommandot finns inte
l2ping: komut yok
l2ping: nie znaleziono polecenia
l2ping: níor aimsíodh an t-ordú
l2ping: no se encontró la orden
l2ping: no s'ha trobat l'ordre
l2ping: opdracht niet gevonden
l2ping: parancs nem található
l2ping: perintah tidak ditemukan
l2ping: príkaz nenájdený
l2ping: příkaz nenalezen
l2ping: команда не найдена
l2ping: командата не е открита
l2ping: 命令找不到
l2ping: コマンドが見つかりません