Is it possible to share same subnet in 2 locations How does it work?
What is in routing tables in both locations.
A hospital wants to put a special purpose gateway server for a prioprietary IP intergrated nurse call system in a remote location. The gateway needs 2 needs 2 nic cards, one for data and one for voice (or it can use one sharing both) ,it makes it possible for devices on one vlan to talk to another.
After some further discussions of the Nurse Call network requirements we are very concerned about extending the Nurse Call VLAN through core of the hospital network since it was disclosed that there is no loop prevention mechanism on that VLAN and there is none in the core of the hospital network. A diagram shows a UTP connection to the hospital LAN in the 2nd floor presumably this is only to connect to the inside interface of the special purpose Gateway Server. If so, I feel it would be better to locate that gateway in inside hospital instead remote location to prevent the possibility of an nurse vlan loop affecting both networks. Although we typically prefer servers to be located in the remote Data Center, in this case it appears that the risk involved in extending that nurse VLAN to the Data Center outweigh any benefits, especially since there does not seem to be any redundancy built into the gateway. I believe it was stated in the meeting that the connection to the hospital LAN could be located in any onside center so we should consider locating it here with the infrastructure to support servers in the hospital building.
The client prefers servers at a remote location (all in one place) but there is a risk of extending vlan.
Can they do that? What would be their best solution?
Sure it's technically possible. And if the both sites are indeed in the same subnet, then there would be no routing done. So instead of routers between the two locations, you'd have network bridges. Or perhaps a VPN tunnel to tunnel the traffic through a routed connection.
One problem that comes to mind immediately is the size of the pipe connecting the two locations - since bridge will send all broadcast traffic through the slow connection, it can bottleneck quickly.