rundig: 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/rundig - from package: htdig

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

On Debian possible default full paths are:

/usr/bin/rundig - from package: htdig

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

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