randpkt: 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/randpkt - from package: wireshark

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

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