mktap: 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/mktap - from package: python-twisted-core

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

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