dnsmap-bulk: 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/dnsmap-bulk - from package: dnsmap

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

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