Inter VLAN Routing using same Subnet

[trumpcyclops1]

I am having 2 VLAN

VLAN1 - IP range 192.168.1.1 to 192.168.1.99 subnet 255.255.255.0 i.e. I have 100 host in VLAN1
VLAN2 - IP range 192.168.1.100 to 192.168.1.199 subnet 255.255.255.0 i.e. I have another 100 host in VLAN2

Now I want to communicate in between the above 2 VLAN, for that I can place router with multiple sub interface equal to number of VLAN's i.e. in our case 2. The issue is that same subnet IP cannot be assigned to different sub-interface over the router.

As a solution to this I see many tutorials using complete different set of IP having differing by subnet. But then what is point to subnet, since we already have altered the subnet. That can be done any way even without VLAN.

What is the solution keeping same subnet IP's. Do share some tutorial or configured .cpt file.

[Mark Malone]

Hi

The only way to have same ip ranges on same device is one would have to be isolated with something like a vrf in its own routing table so theres not a conflict in routing  , or above split the subnet between vlan 1 and 2 --255.255.255.128 that way you can have 126 hosts 192.168.0.1 -126 

[trumpcyclops1]

Ok assuming I used your 2nd idea, Now suppose I have to migrate 1 host from VLAN1 to VLAN2 now do I need to change my IP to other subnet prepared for VLAN2 ? 

[Mark Malone]

You would change the user ip to be in the range of that vlan if not part of dhcp and then change the access port that user connects to the same as the vlan id ther in

[Bernhard82]

VLANS are used to separate broadcast domains. VLAN 1 and 2 are all the the same broadcast domain.

If you change the same mask  this will work. ie 255.255.255.128

[trumpcyclops1]

I observed that even when we use 255.255.255.0 mask just by using VLAN I can separate broadcast domains. 

One more thing, what if I take IP range this way

VLAN1 - IP range 10.0.0.0 subnet 255.0.0.0 
VLAN2 - IP range 12.0.0.0 subnet 255.0.0.0 

[Mark Malone]

There separate ip ranges so separate broadcast domains , There class A so only the first octet counts in terms of range