ifdata: 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/ifdata - from package: moreutils

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

On Debian possible default full paths are:

/usr/bin/ifdata - from package: moreutils

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

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