Use multiple DSL circuits on the same network
Posted on 2007-04-01
I have a probably simple networking question for those individuals who are Cisco experts. From my initial Internet research, I know most everyone's first solution to this will be to buy a device that allows me to plug two ADSL circuits into it and share them equally. I stress, BUYING NEW EQUIPMENT IS NOT AN OPTION FOR ME.
I am going to install a LAN that provides ADSL service to approximately 100 people. There is no fiber going between the ISP and the MDF where the ADSL circuits will be terminated in.
Unfortunately, this limits us to home circuits that the ISP recommends for no more than 5 people. One good thing, however, is that I can get 6 of these home ADSL circuits to the building with the LAN. Realistically, each circuit should be able to service 15-20 people adequately so bandwidth should not be an issue using all 6 circuits.
Each user must be on the same network to facilitate a web application and printing. The ADSL circuits are evenly distributed on the 4 walls of the building (it’s an open gym) and I can use as many switches as I need to for the LAN drops. The ADSL routers provide the DHCP for the clients. Each ADSL router defaults to a 192.168.0.X/24 subnet with the ADSL router being the gateway. Essentially it gives this configuration:
IP Address <RANGE> 192.168.0.2 - 192.168.0.33
Gateway 192.168.0.1 <ADSL ROUTER>
DNS Server - 192.168.0.1 <ADSL ROUTER>
I have pretty new Cisco equipment and can bring a 3700 series router (2 FastEthernet ports) and 3750 Layer 3 switches to provide LAN connectivity to the users. (I could also bring a 6509 if this equipment does not cut it.
Here is my plan. Leave one ADSL router with the default subnet. Change the configuration of the other 5 routers to different subnets. (Each DHCP range will be changed accordingly like the 192.168.1.X example below):
192.168.1.X/24 DHCP <RANGE> (192.168.1.2 - 192.168.1.33)
Each router will service a section of the building. However, each switch from each subnet will be connected. I will put a router on the network to route between these subnets in order to facilitate the web application and printing mentioned above.
Question 1: Is this a good plan?
Question 2: If this IS a good plan, then how should I configure the router? I’m guessing I need to use router on a stick since I only have 2 FastEthernet ports on the router?
Question 3: Was I smoking crack when I came up with this plan? If so, can someone suggest a better setup?