Cable Modem IP vs Router IP

[mainit123]

I have a Siemens Speedstream 4100 modem providing DSL service. This device comes with a default IP of 192.168.0.1 and that has been the active IP address on that device from day one. I am now installing a D-Link 2310 broadband router that comes with the same default address of 192.168.0.1 It would seem like I should re-address the D-Link router to 192.168.0.2 in order to avoid an address conflict. I am going with DHCP on the D-Link router to automatically provide addresses to the 3 PCs that will connect to the D-Link router. Alternatively, if I went with static IP addressing, I would specify 192.168.0.3, .4, and .5 for each of the PCs.
Is this IP addressing scheme correct?

 

[Crowtalks]

As long as the speedstream does not have dhcp enabled, you shouldn't have an address. If the computers are receiving dhcp and dns info from the dlink, make sure you tell the nics to receive dns from 192.168.0.2 I would assign a different addressing scheme to the dlink myself. Something like 192.168.10.xx or 172.16.100.xx, just for the heck of it and then you don't have to worry what the speedstream does or doesn't do. Of course you are setting up a double NAT situation which provides a little more security but can create vpn headaches.

 

[Crowtalks]

What does this have to do with cable, by the way?

 

[Crowtalks]

I meant for the first sentence to end in 'address problem'
Sorry

 

[jimbopalmer]

This will go better if you admit you have a Siemens Speedstream 4100 router and you are trying to add a second router, a D-Link 2310 broadband router for some reason.

http://www.calweb.com/dsl/SpeedStream_4100.pdf

If you renumber the D-Link 2310 broadband router to some other subnet, say 192.168.1.1 it will work better.

A more fundamental question is why do you want two routers, it is almost never the best way.


I tried to remain child-like, all I acheived was childish.

 

[mainit123]

Gentlemen:
Thank you all so much for a series of prompt and robust replies!
Of course, I have to give myself 50 lashes for implying this Siemens Speedstream is doing DSL when in fact it is cable. My apologies to Crowtalks. I am dealing with Cox Cable installing cable service in a new business in Oklahoma City so it is truly cable.
In fact, the actual cable modem they are supplying is a MYSTERY until tomorrow morning. By this time tomorrow, I will be able to report on what they furnish unless someone out there knows already what their default choice is for business customers. I have the Speedstream 4100 at home so that was my only reference point.

I will request that the Cox installer NOT enable DHCP on whatever cable modem they supply. I was assuming I was not overkilling this scenario by installing the D-Link router as I didn't know of any other way to furnish DHCP. If in fact, when an ISP supplies a cable modem, it is already capable of furnishing DHCP to the three downstream PCs, then it sounds like my D-Link is probably extraneous?

More specifically regarding Crowtalks' post, if the D-Link is set to 192.168.10.xx or even 172.16.100.x, how can the cable modem at 192.168.0.X see the D-Link unless it is within that 192.168.0.X subnet? I know that sounds like a newbie network question but is the bottom line that it really doesn't matter what the D-Link is set to (assuming it is one of the private non-routable addresses), it will still pass traffic back and forth through the cable modem?

Finally for jimbopalmer, is the Speedstream 4100 considered a router? I am going to assume what Cox supplies tomorrow is truly a modem, not a router. I wasn't trying to deceive anyone with my description of this scenario but it sounds like a Speedstream with a D-Link EBR2310 is considered a two router environment.
So, how does giving the D-Link an address of 192.168.1.1 with the cable modem at 192.168.0.1 allow it to work better?
Again, thanks for your great help so far.

 

[Crowtalks]

Every router has a WAN (to the world) and a LAN (to my clients) side. If your speedstream 4100 is in the subnet of 192.168 0.1 then you could assign the WAN of your DLink to 192.168.0.2 with a /24 mask (255.255.255.0) and a gateway of 192.168.0.1 this tells your Dlink that it's next hop router is the speedstream.

This allows you to set up a LAN behind the DLink using a different private addressing scheme, such as 192.168.1.1, with the DLink as 192.168.1.1, or something else, this makes the DLink master of your local network.

Actually, your Cox Cable modem will most likely have a public IP to assign the WAN side of your DLink router. Just make sure you get the gateway IP, your subnet mask, your available IP and your DNS server addresses (should be two).

You should see the fields in the DLink WAN info where you enter this info.

Be sure and do your ping tests and maybe trace routes from a client pc for connectivity.

I wouldn't concern myself about DHCP between the two devices if you choose different subnets for your devices.

 

[jimbopalmer]

OK the Siemens Speedstream 4100 router is not involved at all and was just added to the discussion to insure bad advice, right? This has nothing to do with DSL?

All you really have to install is some modem the cable guy brings and the D-Link 2310 broadband router, right? If the modem is JUST a modem, that should be fine, no special instructions needed. If the modem is also doing IPTV or VOIP then it is more than a modem and we are back to two routers.


I tried to remain child-like, all I acheived was childish.