Security: Cameras in the same subnet with WLAN ans Computers

Hello everybody

I need some suggestions on how to configure my network for security reasons.

Configuration now: I have a subnetwork ( 192.168.2.X ) which includes
around 40 linux and win boxes, there are also 2 WLan Accesspoints in the
subnet. There is also a linux gateway with firewall for access to the
public internet. DHCP is also installed and delivers IPs for example,
Laptops, which connect to the WLAN AP.

Now we get some Cameras with ethernet connection, to watch some secret
things :-) The problem ist now, i connect this cameras into the same
subnet, but it's now a security problem with this WLAN APs. Just known
computer should have access. The cameras delivers the viedo stream by an
java applet.

Accesspoint has MAC - AccessControl and WEP (128bit) and the cameras has
also a password control.

My first thinking was, create a second subnet (192.168.3.x) put the
cameras into it and connect the computers from the other subnet via
ipsec. <- good idea ???

I hope some of your expert guys could give me good suggestions.

Volkan