Network Config

[chingching]

Hello All,

In our building we have about 5 computers on a router. One guy has configured his wireless router which he uses to hook his laptop up to , to use the ip. address 192.168.1.2

My feeling is this conflicts with all other users trying to hook to the internet with the "default gateway" of 192.168.1.1

So one question is : 1. does each separate computer use a unique gateway to the router? So if the 1st computer to go online grabs 192.168.1.1, is that address closed to all other computers, or can other computers use the SAME gateway at the SAME time?

2. Is there somewhere possible to see what gateway is being used. ipconfig on XP shows the default gateway, but doesn't say what the actual one might be. Is this the same as DHCP server ?

3. If 192.168.1.1 is the default gateway and that is not available, does the computer search for another gateway in a particular order, e.g. 192.168.1.2 1.3 1.4 etc ?

[ignis]

Hello All,

In our building we have about 5 computers on a router. One guy has configured his wireless router which he uses to hook his laptop up to , to use the ip. address 192.168.1.2

My feeling is this conflicts with all other users trying to hook to the internet with the "default gateway" of 192.168.1.1

So one question is : 1. does each separate computer use a unique gateway to the router? So if the 1st computer to go online grabs 192.168.1.1, is that address closed to all other computers, or can other computers use the SAME gateway at the SAME time?

2. Is there somewhere possible to see what gateway is being used. ipconfig on XP shows the default gateway, but doesn't say what the actual one might be. Is this the same as DHCP server ?

3. If 192.168.1.1 is the default gateway and that is not available, does the computer search for another gateway in a particular order, e.g. 192.168.1.2 1.3 1.4 etc ?

Under 'Connection' > 'Lan' you can set as Auto, and it should find all

or click 'Advanced' and set it yourself.. = info from your provider, then the number of cable in your router..

myself 192.168.1.2 = this PC, 192.168.1.1 = TV Dreambox, 192.168.1.3 = Bedroom TV Dreambox, 192.168.1.4 = Upstairs PC, 192.168.1.5 = Laptop

Problems still? phone your ADSL provider and they will talk you through it all, here out in the sticks 50km from BKK there is only one option TRUE, they came out and set it up for me and also came to 2 others at different times when we had problems, Big supprise NO Charge FREE

[RKASA]

If the router is connected to the ISP's modem be it ADSL or sat or DSL should not matter, If set up is using DHCP router will give an local IP to anything when it gets connected. Mine even changes local IP if I switch OS's that I am using with the same PC. When first connecting the router it sets the gateway normal the first local IP in the range of the router. Then the NAT routing table in the router will auto provide a IP to PC and devices that connect to it by ether a cat cable to port of router or by the wireless. If you use dhcp and the last IP you had is in use it will just give you a new one. It normal best that DHCP mode be in use. edit add: if he is up linking his wireless router to the router that everybody else is using then it should be in DHCP mode and it will connect as if its a device or another PC and his wireless will take care of his local IP for him.

Edited September 3, 2007 by RKASA

[autonomous_unit]

Hmm, reading the replies so far I am not sure if your problem is being addressed... I assume that you mean there is a router in the building supporting multiple users and using the subnet 192.168.1.0/24 (most likely with the router using 192.168.1.1 as its own address and providing DHCP to allocate addresses for users in the building).

Your neighbor should just configure his own router to use DHCP on the WAN port to get an address from the building router, or else coordinate with the operator of the building router to set a static address which is outside the DHCP allocation range for the building router. Otherwise, yes, there is a risk that his chosen static address could conflict with DHCP assignments being given to other users. The configuration of the building router would have to be viewed to be certain of the situation... usually there is a simple DHCP server configuration section which gives an address range or "pool" to dynamically allocate.

I know on my own routers, the default usually starts with, e.g., 192.168.1.2 and goes up to 192.168.1.64 or something like that. It is not necessary to use the entire subnet for automatic allocation unless you really have 254 users etc.

Once he gets a non-conflicting address for the WAN port of his router, it shouldn't matter how many devices he puts behind it, as they will all share the single address via his own router's NAT function. He would probably need to configure his own router's LAN subnet to a different address, e.g. 192.168.2.0/24 to avoid problems, as some NAT implementations might not cope well with the same subnet address being used on both LAN and WAN interfaces.

[tjo o tjim]

Not enough info to really tell what is going on; the wireless network and wired network could be on separate NAT segments. By calling is wireless access point a "router," that infers that it performs NAT (Network Address Translation). So, he could wirelessly give out 192.168.0.7, while another computer uses 192.168.0.7 from the wired network. This should work just fine, although it is confusing and ugly.

To confirm if that is the case, type the following command from the command prompt on a wireless client: tracert google.com

The first hop should be the wireless router (say 192.168.0.1), and then you might see a second hop with the same address. I think this is a double-NAT configuration.

What is a problem is if the wireless router is set with a fixed "gateway" IP address that is in the DHCP range of the wired router-- then two machines can actually be trying to use the same address on the same NAT.

Hope this helps...

[Firefoxx]

A gateway is, to put it simply, the "gateway" or door for the computers on the network to get to other networks (in this case, the internet). In most cases, there is only one gateway (the "default"). It's usually assigned either the lowest (.1) or the highest (.254) ip. The rest of the computers get assigned unique (as in different from each other) IPs, and all will use the same gateway (ie. the router). Normally, for a home setup, the router will have a DHCP function, which does the job of automatically assigning unique IPs to client computers when they are booted up into the OS. You normally don't need to assign them manually on the individual computers.

Since you have that one guy who has a problem, you have a few choices:

1. Make that guy configure his other router so that it uses DHCP.

2. Make your own router's DHCP settings work with that one guy.

3. Kick that guy out.

4. Make that guy use an "alternate" TCP/IP setting.

[nikster]

Hello All,

In our building we have about 5 computers on a router. One guy has configured his wireless router which he uses to hook his laptop up to , to use the ip. address 192.168.1.2

My feeling is this conflicts with all other users trying to hook to the internet with the "default gateway" of 192.168.1.1

So one question is :

1. does each separate computer use a unique gateway to the router? So if the 1st computer to go online grabs 192.168.1.1, is that address closed to all other computers, or can other computers use the SAME gateway at the SAME time?

No, all computers use the same gateway.

The DHCP server assigns addresses to any device that asks. It will happily assign 192.168.1.2 to some device, because it doesn't know that your friends WiFi router is already at that address.

The solution to your problem is that you can set up your DHCP server to start its pool of IP addresses at, say 30. Then, you can use 192.168.1.2 - ...29 for devices on your network that want a fixed IP address. Your friend can then make his wireless router use .2, for example.

Whatever happens, each device on the network needs to have its own IP address.

You then also need to check the wireless router's settings and make sure it's not set to act as DHCP server. It needs to be set up such that your main router is the one and only DHCP server on your network. Two DHCP servers will cause problems.

2. Is there somewhere possible to see what gateway is being used. ipconfig on XP shows the default gateway, but doesn't say what the actual one might be. Is this the same as DHCP server ?

It's the same because in a normal setup the same box acts as both the DHCP server and the DNS server.

3. If 192.168.1.1 is the default gateway and that is not available, does the computer search for another gateway in a particular order, e.g. 192.168.1.2 1.3 1.4 etc ?

No. It doesn't search.

Edited September 3, 2007 by nikster

[technocracy]

Hello All,

In our building we have about 5 computers on a router. One guy has configured his wireless router which he uses to hook his laptop up to , to use the ip. address 192.168.1.2

My feeling is this conflicts with all other users trying to hook to the internet with the "default gateway" of 192.168.1.1

So one question is : 1. does each separate computer use a unique gateway to the router? So if the 1st computer to go online grabs 192.168.1.1, is that address closed to all other computers, or can other computers use the SAME gateway at the SAME time?

Gateway is just another name for a router - all PCs will have a single default gateway. Nothing more nothing less. The default gateway if you have DHCP enable is provided to the PC by the DHCP server.

2. Is there somewhere possible to see what gateway is being used. ipconfig on XP shows the default gateway, but doesn't say what the actual one might be. Is this the same as DHCP server ?

The main concern here is does the wireless router have DHCP enabled also? The wireless will be seen as just an extension of the Ethernet segment once the wireless device is connected it should get it's IP address provided by your existing router (non-wireless).

3. If 192.168.1.1 is the default gateway and that is not available, does the computer search for another gateway in a particular order, e.g. 192.168.1.2 1.3 1.4 etc ?

Computers do not search for routers - if more than one is configured it will attempt to load balance packets between the routers - but there is no need for this to be configured.

First off I am guessing the wireless router is a broadband router but the broadband isn't connected?

In this scenario the Wireless router having an IP address is just for management nothing else - since the only time it would be routing traffic is if it was 'routing' between the Ethernet/wireless segment onto the broadband interface.

The wireless router is just acting as a LAN extension for wireless access - nothing else. All DHCP, NAT functionality etc should be disabled.