mkrfc2734: 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/mkrfc2734 - from package: libavc1394

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

On Debian possible default full paths are:

/usr/bin/mkrfc2734 - from package: libavc1394-tools

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

Error in other languages:
mkrfc2734: bevel nie gevind nie
mkrfc2734: comandă negăsită
mkrfc2734: comando não encontrado
mkrfc2734: commande introuvable
mkrfc2734: command not found
mkrfc2734: käsku ei ole
mkrfc2734: không tìm thấy lệnh
mkrfc2734: komanda nerasta
mkrfc2734: Kommando nicht gefunden.
mkrfc2734: kommandot finns inte
mkrfc2734: komut yok
mkrfc2734: nie znaleziono polecenia
mkrfc2734: níor aimsíodh an t-ordú
mkrfc2734: no se encontró la orden
mkrfc2734: no s'ha trobat l'ordre
mkrfc2734: opdracht niet gevonden
mkrfc2734: parancs nem található
mkrfc2734: perintah tidak ditemukan
mkrfc2734: príkaz nenájdený
mkrfc2734: příkaz nenalezen
mkrfc2734: команда не найдена
mkrfc2734: командата не е открита
mkrfc2734: 命令找不到
mkrfc2734: コマンドが見つかりません