HowTo: http://support.clouditsp.com/index.php?/Knowledgebase/Article/View/102/0/how-to-setup-a-guest-wifi-network-on-a-mikrotik Additional Info: http://forum.mikrotik.com/viewtopic.php?t=81061

If you need any wired ports to be part of the guest network, you'll need to create a bridge br-guest and bridge the vAP and desired Ethernet ports and adjust the following as necessary.

The existing NAT (masquerade) rule may be sufficient to NAT both the LAN and the Guest networks. For example, if the existing NAT rule masquerades all traffic going out ether1, that is probably sufficient for both networks.