VLAN or L2 subnet between core router and firewall?

[the-lebowski]

Wondering if there is a best practice?  In my current office I used just a L2 subnet between the two. a routed interface on my core 3705.  I am wondering if I can just create a vlan and configure it that way instead?

[Antonio Knox]

I'll assume you meant a 3750 here.  Assuming a basic setup here, you should definitely house the SVI (Switched Vlan interface) on you core 3750 and propogate the vlans as needed throughout your network using VTP (Vlan Trunking Protocol).