I have a 4 port module in my 3800 router, an HWIC-4ESW, that acts like a switch. I can configure IPs on each port if I do something like the following:
conf t int F1/1 switchport access vlan 20 <CTRL-Z> vlan database vlan 20 exit int vlan20 ip address 192.168.1.1 255.255.255.0
If I do this for multiple ports, and then connect different switches to each port:
- Do I need to do any configuring of the vlans on those switches? I would think not since I am using switchport access instead of trunking?
- If I configure multiple ports this way, will the clients be able to talk to each other via Layer 3 (Through the router) and not layer 2? I have seen some posts that vlans are not entirely secure, but my research makes me question that.... (Maybe that is another question)
- How does this end up being different from having multiple interfaces in the router?