Cable modem

[Zeppelin]

I've just had cable broadband put in my house.

The installer chappie said that my Belkin wireless router would not work with Scientific Atlanta modem he had just put in. And he's right :(

Now being a simple soul, I thought by simply connecting the two together with an ethernet cable all should be fine. But no :{

So why do the two not work together and if I buy a new cable wi-fi thingey instead of the supplied one will that solve things?

Thanks for any help

[green granite]

A couple of sites that may or may not help, the second is for a linksys but the principle is the same.

[ Express] New Scientific Atlanta Modem Old Belkin Router - dslreports.com (http://www.dslreports.com/forum/r19884791-Express-New-Scientific-Atlanta-Modem-Old-Belkin-Router)

Getting a Linksys Router to work with Comcast (http://www.elifulkerson.com/articles/router-vs-comcast.php)

[Keef]

I'm surprised if a modem won't work with a wireless router. How would it even know the device connected to it isn't just a computer?

I changed to all-in-one devices a while ago, but I can't recall ever having a problem with a WAP disagreeing with a modem. But I don't use cable, so maybe they do things differently.

[bnt]

Does that Belkin normally connect to the Internet by a special "Internet" or "WAN" port? If so, try connecting it to the new cable modem by one of the normal ports, not the special port.

It sounds like the new cable modem is providing a NAT (http://computer.howstuffworks.com/nat.htm) function, and your old Belkin also provides a NAT function, if you use that special port. You don't want NAT on top of NAT, so if you use a normal port on the Belkin, it ought to act like a dumb "repeater" or "hub", not try to duplicate functions.

[amanoffewwords]

You need a router compatible with the cable modem as an ADSL-flavoured one won't work (see Netgear site (http://www.netgear.co.uk/home_wireless_cable_routers.php) for some info) due to difference in comms protocol.

Plugging it into a normal Ethernet port on your existing router is unlikely to work mainly because it will not release a local IP port to the PC you are connecting until the WAN port is active and even if it did the Internet won't work because there is no route to the outside world for the network traffic to be sent to/received from.