Wifi router not talking to ADSL modem

[Guest]

I have a Speedtouch ADSL modem/router and a Linksys WRT54G wifi router.
I want to connect all my computers via the Linksys router, accessing
the internet only through it's firewall. Everything seems to be working
fine, except the router is not talking to the modem.
Here's the setup:
ADSL Modem LAN interface
IP address: 192.168.1.254
Subnet mask: 255.255.255.0
Primary DNS: 83.143.8.249
Secondary DNS: 83.143.8.246
DHCP: disabled
IP pool 192.168.1.64 thru 200

When I connect my laptop(s) directly to the modem, using fixed IP's, I
can connect to the internet:
IP address 192.168.1.64
Subnet mask: 255.255.255.0
Gateway: 192.168.1.254
Primary DNS: 83.143.8.249
Secondary DNS: 83.143.8.246

The wireless router is working fine with the same laptop reconfigured
without a fixed IP, both wired and wireless:
Linksys router LAN interface
IP address: 192.168.1.1
DHCP: enabled
IP Range: 192.168.1.10 thru 19
Subnet mask: 255.255.255.0

The problem comes when I connect the modems ethernet port to the router
uplink. The Linksys router Internet interface uses the same setup as
the successful laptop setup above:
IP address 192.168.1.64
Subnet mask: 255.255.255.0
Gateway: 192.168.1.254
Primary DNS: 83.143.8.249
Secondary DNS: 83.143.8.246

With the laptop connected to the Linksys router, I can't access the
internet. I can ping 192.168.1.64, which is the Linksys address, but I
can't ping the modem gateway or DNS servers. Is my TCP/IP setup wrong?
Any other ideas?

Thanks in advance.
--TJ

 

[Doug Sherman [MVP]]

It sounds like you have connected the Speedtouch to the Linksys's
WAN/Internet port. If so, this will not work because both of the Linksys
interfaces are on the same subnet and you cannot route between them. Either
change the LAN interface on the Linksys to something other than 192.168.1.x,
or connect the Speedtouch to a Linksys LAN port.

Doug Sherman
MCSE, MCSA, MCP+I, MVP

 

[Chuck]

It sounds like you have connected the Speedtouch to the Linksys's
WAN/Internet port. If so, this will not work because both of the Linksys
interfaces are on the same subnet and you cannot route between them. Either
change the LAN interface on the Linksys to something other than 192.168.1.x,
or connect the Speedtouch to a Linksys LAN port.

Doug Sherman
MCSE, MCSA, MCP+I, MVP

Doug and TJ,

A third possibility would be to run the Speedtouch as a modem, in Bridge mode.
I, personally, would do this, as I am used to Linksys and their NAT / firewall
setup.

If you put the Speedtouch into Bridge mode, you setup the Linksys as normally
used, when connected to a modem. You have to select it as either Fixed,
Dynamic, or PPPoE, depending upon your ADSL service.

 

[Doug Sherman [MVP]]

Not familiar with Speedtouch devices. If it supports bridging, then that
could work as well.

Doug Sherman
MCSE, MCSA, MCP+I, MVP

 

[Chuck]

Not familiar with Speedtouch devices. If it supports bridging, then that
could work as well.

One must hope that it will support bridging. There are too many combo units
being sold nowadays. You buy what you think is a modem, you're stuck with the
router too, and the features of most combo unit routers don't often equal
specialised NAT routers.