Guest networks unsafe?

[Rrrr]

Hi

I have a hard time to understand how setting up a guest network can be made really safe.

My network:
1. Main cable router (DHCP 192.168.10.1) and switch
2. RT-N66U Connected with WAN port to switch.
Can be set as:
a) wireless router for use by guests only
b) wireless access point for use by guests only.
3. Office computer (192.168.10.11), connected to switch. Assume for arguments sake, this computer has no internal firewall.

I have set the RT-N66U (RT-N66U_3.0.0.4_374.35_4-sdk5) as 2a-wireless router (DHCP 192.168.100.1), configured a Guest network and set AP isolated.

-> not safe as guests on the WLAN can still connect to 192.168.10.11 as this address is seen as external to the guest network.

How do I ensure my office computer stays safe and guests cannot reach it??

 

[AndersF]

Enable the guest network option and allow internet traffic only. This option gives the possibility to give the guest network an SSID of its own with own key login.

 

[Rrrr]

Thanks but I have no such option.
I have an option to set Access Intranet which is set to off.