[Lackie]

It appears that you are using the same network range for your Visitors Mode or Office Mode as you are using for your internal network.

If your visitor mode or office mode IP range is the same as your internal Network then this will happen. Change to use a different IP range for your visitor mode or office mode.

If you use the same network for visitor mode or office mode when the destination will receive the packet and then try and route it back to the source. As it's on the same network it won't have to 'route' the packet because it's on the same network, thus it will arp for it waiting for a MAC address to send it to. As this IP address doesn't physically exist on this network then there will not be a reply for it to get a MAC address to send the packet back to. If you use a different network, then the destination will have to route the packet, usually to it's default route.