Bridging Networks

[b-forbes]

Due to corporate downsizing, we are now at the mercy of Consultants to configure our routers. I've been told we must change the configuration (pay a fee) in all four routers to bridge two networks. Can you confirm and give me an idea of the complexity of the change ?

Network 1.

Router A: Ethernet port 10.1.0.4 (255.255.0.0) connected to 48 port switch.

T1 Serial Port 10.2.1.1 (255.255.0.0) connected to Router B

Router B: T1 Serial Port 10.2.2.2 connected to Router A

Ethernet port 10.3.0.4 (255.255.0.0) connected to 48 port switch.

Network 2

Router C: Ethernet port 192.168.20.1 (255.255.0.0) connected to 24 port switch, T1 Serial port 192.168.20.101 (255.255.0.0) connected to Router D

Router D: Serial port 192.168.11.101 (255.255.0.0) connected to Router C, Ethernet port 192.168.11.1 (255.255.0.0) connected to 24 port switch.

What we need is for PCs on Router A (10.1.1.51 etc) to talk to Hosts on Router D (192.168.11.61 etc).

Both Router B and C reside in the same room. Their solution is to add an ethernet board to Router B (192.168.20.3) and connect it to the switch serviced by Router C. They would charge for the new hardware and 3 hours to install and reconfigure Router B. This seems a little high but they also claim they need 3 hours to reconfigure Router A and 3 hours to reconfigure Router C and 3 hours to reconfigure Router D. I can understand Router B but I don't understand Router A, C and D. Can you help a novice understand ?

[bacarpenter]

By connectiong Router B to the 192.168 network you are now creating the situation where devices on any network can communicate with devices on any other network. So if you don't want that to happen, they will be adding access lists to all the routers to prevent un-wanted communications between networks and to only allow the current communications (A-B) (C-D) and the new one (A-C). I use Routers instead of networks to explain cuz I'm in a hurry.

If this is what you want to accomplish then their plan sounds reasonable. AS for the hours estimate, I don't know.

If you don't care if every device can talk to every other than it's an hour job at most. Shut down Router, Add Ethernet interface, Power Up Router, Configure Interface, Test.