You CAN use a hub, but I would not recommend it.. What happens when you use a hub instead of a router is that all of the computers on the hub get IP addresses, and your local traffic goes over the local cable node first. Very bad, and the cable company will not like you for it.
The cable routers are generally firewalls, DHCP servers and 10/100 switching hubs.. The Linksys has port forwarding, and you can set one computer on the router to be in the "DMZ" (Demilitarized zone) which means it isn't behind the firewall at all.
As for being too secure, I haven't had any problems so far. Everything works, although some things (like ICQ transfers) take 30 seconds or so to start..
Cheers,
Backov
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