Subnet Help plz.

[befire]

Hi,

I work in for a small business. We have 3 offices and about 40 computers. I have 1 win2000 server that acts as a pdc, dns server, dhcp server, etc. The three locations are on the same subnet and are connected via a bridged T1 connection and one outbound dsl connection for internet access. I am trying to lower the network utilization to improve the speed between the remote sites to the server. Ive been doing some googleing around and it seems that i need to create 3 subnets. One subnet for each location to reduce broadcast traffic and such.

On top of this I want to change the maner at which the T1's interact. I spoke to covad today and apparently each time data is being accessed from one site to another, the entire groups bandwidth is effected. So as a solution I would like to do the following. Since the two remote sites do not really need to communicate with each other, I would like to create two seperate connections to the main office. Meaning the main office will have two T1 lines. So this means two bridge groups. This way each remote office has a dedicated 1.5mbps vs sharing the 1.5mps connection between the three offices.

The way the T1 lines are connected to the network at each location is simple. There is a netopia T1 router at each location, which is setup by covad for bridge group. I have a switch that sits after this router where all my network components are attached. All components get their ip from the dhcp server located in the main office.

If anyone can shed some light on my issue I would be grateful. I am not quite sure of where to start right now. I am still researching online to see what a typical setup should look like. Im not fully understanding the way vlans, trunk ports, layer 3 switches interact to create a good solution.

[AlexAckley]

This is a fairly simple setup.

What you want to do is setup DHCP at each office on the routers and create static routes on those back to the main office so they can find the AD controller and such.

Put each office in a different subnet... like 192.168.1.x; 192.168.2.x; 192.168.3.x... this way traffic meant to remain at each location such as printing and perhaps file sharing remains within that office and only traffic needed to go the main office or to the internet travels along the T1 pipes.

[befire]

will this setup allow me to browse through the network into other subnets? We use pcanywhere to support users in the remote sites, will I be able to see the pcanywhere hosts in the remote sites from the main office?

[befire]

Thanks, I was totally tunnel vision about this. However I am wondering if this solution will help out on the speed issues.

So this is what i will be doing:

3 subnets-
192.168.1.x - main office
192.168.4.x - remote #1
192.168.8.x - remote #2

at remote #1 I connect a router immediately after the netopia T1 router and set static ip to 192.168.1.249. And set dhcp to 192.168.4.x. Back at the main office router i set static routing to match these.

at remote #2 pretty much same settings as #1.

The only thing that is a turn off is that you cant browse the network across the subnets. Also will this network scheme in fact help lower the bandwidth usage? The added routers seem to be a point of congestion. Then again im not sure of that. any light?

[ua549]

You can assign your PC's NIC multiple IP addresses, one on each subnet. Whether that will accomplish what you want is another matter. I have my notebook PC assigned to my main 10.x.x.x network as well as a 192.x.x.x network. I can access nodes on both networks.

[davis]

Just My 2c.

Filtering broadcast traffic will help a little bit towards reducing bandwidth, but it won't do anything if your actual bandwidth demands go beyond what a T1 Line can provide (which by today's standards is fairly light).

As for the network browsing; you should be able to browse all offices as long as you're at the "Hub" office where the server is located. You'd need to create static routes at the hub as well to tell your packets where to go. Once that's done I can't see any reason why you can't browse the other offices unless the routers are blocking your requests.

A little more detail about the types of applications you're running, where resources are located on the network, types of devices used could help us help you. You should also monitor your traffic to see what types of traffic cause the bottleneck or spikes in the bandwidth.

*Edit*
I just saw your last paragraph, and i recently helped someone out with that here http://forums.enterpriseitplanet.com/showthread.php?t=3142

[befire]

We are definitely not at full capacity on the T1 line. my users are complaining that when accessing the database software from the remote sites, it is sluggish.

From my understanding each time you hit a router in a network you lose "speed". I was wondering whether adding these routers will speed up the network or slow it down. Hopefully you guys can give me some input on the situation.

[davis]

What you've heard isn't entirely wrong. Each router adds a "hop" or a point where the traffic is read up to the 3rd layer to discern which port it needs to go out. however, the speed is effected by the device's cpu, the amount of traffic, and the actual lines the data has to transfer.

To do a test, simply ping from inside the internal networks, and then run ping tests accross the T1 lines at different times of the day. for most applications, you don't want latency to go over 80ms otherwise it becomes noticeable.

Do you have network monitoring software in place to ensure the t1's don't become saturated?

It's also possible that if the only issue is the database application you may need a server upgrade, not a network based one. you need to find the choke point/application at fault before you can resolve.