3560 enabling L3 routing 1

[Mikecl]

Hi

Currently I have 2 * 3560 switches each connected to a trunked router, the 2 routers connect via MPLS between the sites the 3560's are not currently configured for routing.
I have the opportunity to connect a 100mb poini to point connection directly between the 3560's.
I plan to connect the circuit directly between the 3560's and enable l3 routing using the current subnets 172.16.1.0 & 172.16.3.0 ideally I want only the traffic between the two sites to use the link the remaining traffic uses the MPLS. I dont want to alter the other host devices (apart from G.way Address). I was planning to point some hosts to the new gateway to allow the traffic between the sites.

I can enable L3 assign an IP address on the interface but If I try and apply an address I get overlapping address as Mgmt Vlan is used on the switch already. The switch is remote from me so if I change the mgmt vlan address I will lose connectivity as the wan routing is managed externally.
I could use a different address range for the P2P link but then I will have to readress the clients which I dont want to do.
Any other ways of handling this?
Thanks
Is the only way to change the Mgmt vlan

 

[VinceWhirlwind]

If you enable IP routing, then "Mgmt VLAN" loses its meaning.

The issue you might have is that both switches are on different subnets but both using that subnet on the local VLAN1.

Perhaps you should create a "VLAN2" on both switches and assign 10.1.1.1 at one end and 10.1.1.2 at the other, then assign a port at each end into VLAN2, connect the two switches on these ports to the point-to-point connection, then you will need to add a route at each end
172.16.3.0 --> 10.1.1.2
172.16.1.0 --> 10.1.1.1