Communicate between Different VLAN in same subnet

[ankitohc]

Hi Team,

I have one L3 switch and two PC with different VLANs

I know we can't have same subnet for different VLAN's however using this topology.. How can i archive this?

and I can add more devices on top however will not change the configuration.

how VLAN 1 will communicate with VLAN 2 - PC on left to PC on right

[Richard Burts]

The suggested environment where a device in vlan 1 with IP 10.10.2.1 wants to communicate with a device in vlan 2 with IP 10.10.2.2 breaks fundamental assumptions about how vlans work. The crux of the issue with that when 10.10.2.2 sends an arp request for 10.10.2.1 it will be forwarded to devices in vlan 1 but not to devices in vlan 2. This because a fundamental concept of vlan is that a vlan is a broadcast domain.  So a broadcast generated in vlan 1 will not be forwarded to vlan 2.
The suggestions about how to solve this involve ways to fool the environment into believing that there is a single broadcast domain (which happens to have 2 different IDs).
The suggestion to connect vlan 1 access port to vlan 2 access port will work. But what that does is to have a single vlan with different names on each switch. 

[Torbjørn]

I agree with you 100% that NAT is a good solution for many production scenarios that match this description(overlapping networks in separate layer 2 domains). Had this post not had the "aura" of a lab excercise I would not have suggested bridging the VLANs.

[MHM Cisco World]

@ankitohc dont make it long for you' 

Try add ARP in host pc or use router (emulate as PC)

This make each host not send broadcast ask mac of other host or ask for mac of gw.

So host send frame with mac address of destiantion' the sw receive this frame and use it mac table abd forward it to correct port.

That it.

MHM