libnetcfg: 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/libnetcfg - from package: perl-devel

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

On Debian possible default full paths are:

/usr/bin/libnetcfg - from package: perl

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

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