Help Please with IP Addressing On Home Network

I have plans to reconfigure my home network and would like a little advice. First, here is my current configuration:

I have a DSL modem attached to a Netgear Wireless router which the 3 laptops in the household as well as my Dell Desktop access. I had problems setting the router up to begin with and the Netgear tech said it was because both the router and modem had the same IP addy so he had me make several changes. Everything works FINE BUT I would like to get everything on the same subnet, specifically, 192.168.1.XXX.

Subnet mask on everything, is of course, 255.255.255.0

DSL modem is 192.168.1.1

Netgear Router shows TWO IP addys: 192.168.1.47 and 192.168.20.1 NOTE: The 192.168.1.47 IP times out if pinged. I also have a trial version of Network Magic running which shows the router’s INTERNET IP to be 192.168.1.47 and simply it’s IP addy as 192.168.20.1.

My desktop and all three laptops are on the 192.168.20.xxx subnet. And all show the DHCP and DNS server{s} to be 192.168.20.1. My desktop has a cable ran from NIC card to the Netgear router.

If I go into my Westell DSL modem properties sheet, I see that it is set to “Private LAN” with a DHCP range of 192.168.1 to 192.168.1.47. It also has check marks in the two boxes which are, “Private LAN enable” and “Private LAN DHCP enable”. It also states that I have “Discovered Device” on the LAN {My Netgear router} located at IP addy 192.168.1.47 AND that it is inactive.

My plan, is to leave the modem set to 192.168.1.1, subnet mask 255.255.255.0. Then, configure all 3 laptops with an IP address on the 192.168.1.xxx subnet.

Three questions:

1. Using the 192.168.1.xxx subnet and putting all three laptops on that subnet, what should I show the DHCP server to be?
2. What IP address should I give to the wireless router?
3. What should be the configuration of the Dell desktop which currently is connected to the Netgear router via CAT 5 cable?

Thanks!

Jeff Farrar

A few questions for you:

1. Who is your ISP? What is the DSL modem model #?

2. It's generally a best practice IMHO to not use the 192.168.x.x and 10.x.x.x on your network. (It can cause a whole mess of problems when connecting to other networks (vpns and such)

Let me know, and we can help you configure your network to run more effectively.

bb

You only have one option and its super simple if your netgear has switchable lan ports or an uplink port.

Use your wireless router like a hub and forget about the wan port. This means you would plug your dsl modem into one of the lan ports. This will only work if the ports on the router are switchable you will have to refer to your netgear documentation. Most ports nowadays are switchable which is why you see uplink ports on hubs less and less. Then you would simply disable DHCP in your netgear and you are pretty much done. When you renew all of your ip addresses they will all be on the same subnet as the dhcp scope of your dsl modem. Just make sure you disable DHCP on the netgear and set a manual ip address on the lan side of your netgear to the 192.168.1.0 subnet so you can still access the netgear when you finish.

Just so you know, in order to use the wan and lan ports on your router you have to have 2 subnets. Consider it networking law.

There is one possibility here that could happen but is unlikely (at least I haven't ran into it on any soho router I have used). That is your wireless clients will not get an ip address assigned if dhcp is disabled in the netgear in which case you would disable dhcp in your dsl modem and leave dhcp enabled in the netgear but you need to copy the dns server entries from the dsl modem over to the netgear dhcp.

Also FYI you can't have two DHCP servers on the same segment of a subnet with the same scope.

I am curious what you feel the benefit of one subnet is considering your router and modem are working perfectly?

If you have the router set to provide DHCP, you don't need to set anything else except to put the computers to get an IP automatically.

Set the ip of the netgear to 192.168.0.1 and attach the modem either to the wan port (if it has one) or to one of the ports. If you post your modem and router models, I can be more specific.

Shut down all the computers. Restart the modem and then the router. When the modem lights are showing a stable connection, fire up the router. When the router has sorted itself out (give it a couple of minutes) fire up the computers one at a time. Each should be given an IP by the router. The modem get's its own IP from your ISP.

Each computer should then show a gateway ip of 192.168.0.1 and have an address 192.168.0.x

You can restrict the DHCP scope on the router if you like, if you only have a few computers, what point allowing the router to issue 253 IPs? Restrict it from 192.168.0.2 to 192.168.0.10 (note that 192.168.0.1 must not be in the scope since the router is using it and you don't want it handed out).