A friend of mine said to me that Cisco does not allow MT to create APs with ROS. I have a Dell OptiPlex XM 590 and the card from Cisco, Aironet 4800. Planing to use an Omnidirectional antenna with it. I know that the server is an old one, but i will use it for a small area max. 30 clients.
I'm asking if this is possible?

Thank you

Are you sure that this card is supported ?
http://www.mikrotik.com/testdocs/ros/2. ... erlist.php

yes it is supported: Aironet ISA/PCI/PC4800 2.4GHz DS 11Mbit/s Wireless LAN Adapters (100mW)

Aironet doesn't support AP mode, only ad-hoc and infrastructure. you have to use a Atheros card