vxi11-cli: 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/vxi11-cli - from package: python-vxi11

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

Error in other languages:
vxi11-cli: bevel nie gevind nie
vxi11-cli: comandă negăsită
vxi11-cli: comando não encontrado
vxi11-cli: commande introuvable
vxi11-cli: command not found
vxi11-cli: käsku ei ole
vxi11-cli: không tìm thấy lệnh
vxi11-cli: komanda nerasta
vxi11-cli: Kommando nicht gefunden.
vxi11-cli: kommandot finns inte
vxi11-cli: komut yok
vxi11-cli: nie znaleziono polecenia
vxi11-cli: níor aimsíodh an t-ordú
vxi11-cli: no se encontró la orden
vxi11-cli: no s'ha trobat l'ordre
vxi11-cli: opdracht niet gevonden
vxi11-cli: parancs nem található
vxi11-cli: perintah tidak ditemukan
vxi11-cli: príkaz nenájdený
vxi11-cli: příkaz nenalezen
vxi11-cli: команда не найдена
vxi11-cli: командата не е открита
vxi11-cli: 命令找不到
vxi11-cli: コマンドが見つかりません