login.radius: 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/sbin/login.radius - from package: radiusclient-ng-utils

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

On Debian possible default full paths are:

/usr/sbin/login.radius - from package: libfreeradius-client-dev

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

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