My girlfriend has just acquired an airport express to connect all of her apple devices. At the moment, I am running an Asus RT-N16 with Tomato firmware with multiple VPN clients setup within this router What I want to achieve is a seperate network for her, so if I configure the VPN to start on the Asus, it won't affect any of her devices. I am running a modem in bridge mode going to the Asus if that helps.
You can add it to the network & use it as an access point or double NAT for an internet address but unless you get multiple static IP's from your ISP you can't give her an internet connection that isn't effected by your router
I have an airport express and a wrt54g running tomato. I've not been able to achieve what you're after because i only get a single static IP address, and i don't believe the airport is vlan capable unless it was added in a recent revision. i believe one of the branches of tomato adds vlan support, check here: http://en.wikipedia.org/wiki/Tomato_(firmware) incidentally, I'm waiting on delivery of a proper (read: managed) switch which is vlan capable. I'm going to see if by attaching the airport express to it I can get that traffic properly tagged, but i suspect it won't work; that isn't why i bought the new switch, it just happens to have 802.1q supported.
smart switches and managed switches, usually have vlan support, your managed switch can indeed tag stuff going to and from the airport via a setting on the port the airport is connected to.
