I was looking into the CARP tutorial http://pfsense.iserv.nl/tutorials/carp/carp-cluster-new.htm.
I would like to know the kind of switch which I can use as indicated in the figure (the upper layer switch). Can I use Layer 2 switch only? Or it should be Layer 3 switch?
GruensFroeschli last edited by
A switch is per definition on Layer2.
A Layer3-Switch (i dont like this expression) is not much more than a router with many many ports.
But to answer your question directly: a Layer2 switch is sufficient. (you could even use a hub –> Layer1).
I think what originally brought on the "layer 3" switch term was that the ports on the switch still remain as switch-ports and the switch has the capability of multiple switch virtual interfaces (addresses on a VLANs) and a routing table. The actual switching is still performed by ASIC hardware.
Many of them now; however, allow an interface to be directly addressed as a routed port now which does make it hard to tell if you have multi-port router or a switch.
It's a safe assumption that when people mention a switch, they are not referring to a routing capable device.
The ports need to be on the same broadcast domain. That can be accommodated (or not properly accommodated) with a L2 or L3 switch.