VLANs setup using Cisco 3750G
Posted on 2011-05-05
I have been assigned a task to re-organize network with very minimum resources and in a very short time, below is the current setup:
There are 5 different locations with distance of 200-300 meter among them, each location has multiple small 8-ports or 16-ports unmanaged network switches, but these 5 locations are connected to a central location through fibre optic backbone.
As of now there is no organization of IPs, 4 different series of IP addresses are used in clients and servers, 128.128.x.x, 192.168.1.x, 192.168.2.x, 192.168.10.x, all PCs are assigned fixed IP addresses and most of them have multiple IP addresses assigned to reach servers available on different IP address range, very bad network, i know, but that is how it came to me.
Now my task is to bring everyone on one IP address which should be assigned by a DHCP address, I'm planning to divide this network in different VLANs managed by a 3750G switch, but challenge is we cannot stop/change existing servers IP addresses untill unless all clients are new IP address scheme which is not a very easy task.
5 VLANs, 1 for each location + Server VLAN for devices/servers directly connected to core switch (3750G)
Connect all servers (10 in number) to 3750G switch.
Connect all 5 cables coming from 5 different locations to 3750G switch
Let servers running in their old IP addresses until all clients are on new IP address scheme, let 3750G do the routing for us.
Suppose, cable coming from location A is connected to port number 12 of switch and we configure it as VLAN1, we have to change all clients to obtain IP addresses automatically, we'll configure a proper scope in our DHCP server to assign IP addresses for VLAN1 but request will come from 3750G switch, please note that DHCP server would be running in old IP address range i.e. 128.128.x.x
First of all, I would like to know what I'm thinking, is it practically possible? if yes, then how client and server which are on different IP address range will communicate to each other? How about internet traffic which has to pass through an internet gateway (also connected to core switch 3750G switch) but on a different IP address range?
Please note that I have only 1 manageable switch in this whole network and that is at core.
Sorry for such a long post.