Hmmm... it's not "bad" per se, but more like confusing... Layer 2 is addressed by MAC addr's which are flat address space (non-routable) constructs; this creates a Layer 2 broadcast domain, also called a "segment". You can then map one or more IP networks (Layer 3 addressing) to a Layer 2 segment. If you map more than one L3 network to a segment, you can get into some headaches, such as having to address multiple IP addr's on each host and router interface (one for each network) with the attendant confusion, and also that broadcasts produced by each IP network (i.e. ARP requests) multiply, and bandwidth is consumed. Most networking professionals agree that it's best to only map one IP network to one Layer 2 segment, and that's what I was trying to convey here. I guess I could say something like the above if explanation is needed...