router: 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/router - from package: jabberd

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

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