bombardment: 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/bombardment - from package: siege

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

On Debian possible default full paths are:

/usr/bin/bombardment - from package: siege

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

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