linksys wrt54gx behind modem/router

[encinitas]

i have a remote user with a linksys behind the modem that acts like a router (with 4 ports). linksys was added for the wireless connection.
when plugged directly into modem, the gateway is 192.168.1.254

i'm having problems making the linksys work behind the modem. am i supposed to turn off NAT on the linksys? or assign static ip's with .254 as the gateway? i'm stumped.

thanks in advance

 

[encinitas]

anyone?

 

[CiscoGuy33]

encinitas,

I think you should check your documentation for your modem and see if it can be put in a "bridge" mode so that it is just your DSL connection and passes everything to the Linksys. The Linksys then could get an IP from the ISP through the modem.

If not then you will need to change the LAN address on the Linksys - by default Linksys uses 192.168.1.1 and since the modem is 192.168.1.254 it is already using the 192.168.1.x network. The Linksys WAN should be 192.168.1.x as long as you do not use 192.168.1.254 that is being used by modem.

You could change the Linksys to 192.168.2.1 (LAN) and then it should DHCP 192.168.2.100-199 to those that attach to it. The gateway for those devices would be 192.168.2.1 (the Linksys) and you might have to go into advanced routing features in the Linksys and setup so that any traffic other then 192.168.2.x is forwarded to the modem which will then send it to the Internet.

I hope this helps!



E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[encinitas]

thanks-
i disabled NAT on the router, and on the pc's i put in static ip's, using .254 as the gateway. i couldn't figure out how to get the wireless router to kick out dhcp addresses that include that address for the gateway, so i just input statics for now.
seems to work fine.
the modem is in spanish (brother lives in baja malibu), so i didn't want to mess with it!

thanks again.

 

[pudda]

Static your Linksys WAN port with an ip address within the dhcp range of the modem such as:
ip 192.168.1.25
subnet 255.255.255.0
gateway 192.168.1.254
DNS1 192.168.1.254 (this is what most people leave out and can't get it to work).
Then static the LAN on a different range:
ip 192.168.2.1
subnet 255.255.255.0
DHCP should be giving addresses in the 192.168.2.xxx range, or set them manually for as many/few as is needed.
If you have NAT turned on in the modem you do not need it in the router. A lot of modems use natting plus some sort of firewall, so having them in the router (and a firewall on your computer) is simply overkill in my opinion.

The test continues...