bridge: 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:

/sbin/bridge - from package: iproute

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

On Debian possible default full paths are:

/sbin/bridge - from package: iproute2

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

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