AT&T U-Verse with external wifi router running DD-WRT software

 

I don't like the way wi-fi connection is handled by CPE (Customer Premise Equipment, such as the provider's home gateway/router), so I want to use the Wi-Fi capability of Linksys.  DD-WRT gives features in handling L2 connections (MAC filtering etc.),  but I still want the CPE to handle DHCP and NAT services.  Basically, I just want to make the Linksys router acts like a Wi-Fi and Wired switch, as an extender of the existing CPE.

 The objects in yellow box represents component in the Wi-Fi router (in this case, a Linksys WRT54G running DD-WRT firmware).

DHCP server on U-Verse CPE is configured to give IPs in 192.168.0.x subnet.  The CPE address is set manually to 192.168.0.1

Here's what I want:

CPE internal IP address = 192.168.0.1

Linksys Internal IP address = 192.168.0.2

IP range for Clients = 192.168.0.3 - 192.168.0.254

CPE setting:

• Wireless  disabled
• Configure DHCP to assign IP range: 192.168.0.3 - 192.168.254

DD-WRT settings:

• WAN connection type = disable
• Local IP = 192.168.0.2/24
• DHCP server = forwarding to 19.168.0.1 (CPE)
• Check option box to assign WAN port to switch (NAT is thus disabled; it is now acting like a pass-thru to switch)
• Wiress network configuration = bridged (so all Wi-Fi clients are seen by CPE as they're directly connected)
• Wiress Tx Power = 250 mW
• Advanced routing = router (doesn't matter actually)
• Disable CPI firewall
• Routing = disable

This way, all Wi-Fi is handled by Linksys router/switch, but only its L1-L2 layers.  Everything else is handled by the CPE.  We can also relocate the Linksys somewhere else, no need to be close to CPE as long as we have long ethernet cable or by using Powerline extender.