randomip: 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/randomip - from package: ndjbdns

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

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