2 different subnets on single vlan

[cisconoobie]

I have this setup.

2 3750G switches stacked.

I have 2 servers with IP 10.10.10.1/30 and 10.10.10.2/30 connected into port g1/0/1 and g1/0/2 respectivily on switch1 both in vlan 100

I have another 2 servers with IP 10.10.20.1/30 and 10.10.20.2/30 connected into port g2/0/1 and g2/0/2 respectivily on switch2 both also in vlan 100.

I need to keep this same vlan across the stack. In theory servers on same subnet in vlan 100 should be able to communicate properly, or am I wrong?

What can I do to prevent broadcasts from propagating between subnets of this single vlan?

[jorgenolla]

vlan 100 with 2 servers:

10.10.10.1/30

10.10.10.2/30

vlan 100 with 2 servers:

10.10.20.1/30

10.10.20.2/30

These does not allow for another host in either of the subnets; meaning the two hosts will only be able to communicate to each other, since there is no address space for a gateway of last resort in either of the subnets. And still the actual broadcast domain will flood all four ports.

Private Vlan's will work to brake the broadcast domain; but you still don't have the address space for the gateway of last resort in either of the subnets.

[cisconoobie]

I wont need a gateway of last resort.

The 10.1/30 server will get 0.0.0.0 via 10.2/30

The 20.1/30 server will get 0.0.0.0 via 20.2/30

I will try creating 2 communities and see what happens.

These servers are bgp peers.

[jorgenolla]

Use a crossover cable between peers!