Modem -> (WAN)Router1(Ethernet4) -> (WAN)Router2(Ethernet2) -> Laptop but no internet

Ok heres my current setup

Cable modem -> WAN port of Router1 (it is the DHCP server)

all devices and dumb switch (and devices attached to it) connected to the ethernet port (or wireless) of Router1 works fine and can go online and talk to each other.

now from Router1/ethernetport 4 I connect to the WAN port of Router2. (router2 have DCHP enabled also)

now I connect a desktop / laptop to etherenet port of Router2. They get no internet access :( but can still ping each other.

Is there any setting I should do to Router1 or Router 2 to get devices connected to router2 to have internet access?

ohh router1 is a DD-WRT router and router 2 is a cisco small business router

BEFORE YOU SAY IT: I can.
1) just add a dumb or managed switched to the etherent port of Router1 to add more devices
2) disable DHCP of router2 and do Router2/Ethernet <-> Router1/Ethernet. in essence using router2 like a switch/bridge

The reason I am not using those two method is I want more security and total isolation of devices on router2 from being access by crap on router1.

You may say I can just use VLAN to isolate the two networks with the above method. but that is just not taking advantage of the security features of router2 also...

let say router1 or devices attached to it is compromised, the hacker will have to tackle another layer to get to the devices behind router2.

Do you guys have any comment or suggestion? I'm just working with what I have and don't want to put like a bunch more $$ on security apliances .

Is the network flat or segmented?
Does each router have routes to direct traffic to the internet or keep it on the LAN?
If the network is flat, try using a LAN port instead of the WAN port on router 2.
DD-WRT has the capability to assign the WAN port to the the LAN.
Does the Cisco router have that capability?

Provided that the devices are configured correctly it should work under such topology.

Network segregation - http://www.ezlan.net/shield.html


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thanks I got it towork by changin the network IP.

strange though. my internet speed is 50mb down and 8mb up.

on the 2nd router I can't get speed test beyond 26mbps down (8mb up is fine)

I know the speed is well over 50mbps as I did the same speed test on another machine attached to the router1 right after doing a speed test on router2


btw: all the ports on the router are gigE ports

Some routers don't have the throughput to push 50mbps. If you switch the routers (or only use router #2), do you get 50 mb down from it?

It's also possible that the double-NATing is causing inefficiencies, but I think a throughput issue is more likely.