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Routers -vs- Switches?
poochie asks "I'm currently in high school taking the Cisco first year course (semester 1 and 2). We're messing around with routers, and I'm starting to get the idea that routers are being outdated. We're learning switches next semester, but from what our instructor says, switches are just more specific to a LAN. In my mind, they seem more versatile in that they actually control their own ports, rather than having a router which is configured to support lans with switches on them, which have to be configured anyway, and make everything more confusing. I dunno about the purpose or the limitations of each, but from what I see, routers make life difficult for small networks. So I guess my question is twofold: Could anyone list resources on the Web about information on routers vs switches, and does anyone see switches taking over routers/hubs in the future, and making network administration a lot easier? "
A layer 2 (i.e. Ethernet) switch is stretching the definition and a layer 3 switch is just marketing hype.
A switch is a circuit oriented device. A switch such as the 4E, 5E, or DMS receives a connection initiation and responds by connecting an physical source port to a physical destination port. Everything coming into the source port goes right out the destination port.
The so called layer 2 and 3 switches are nothing of the kind. They receive individual packets or frames and examine them and decide which output port each should be sent to. I don't care whether they're examining the IP address, MAC address, or some other "tag". The function they're doing is routing.
I will grudgingly grant you the term Ethernet switch because each port on an Ethernet switch is connected to a device with a specific MAC address. You can sort of pretend that each Ethernet frame is a mini call and the switch is establishing a circuit from source to destination for the duration of a single frame.
A layer 3 switch is really a router. I don't care how many ASICs it has, it looks at each packet and sends it in the general direction of its destination based on information derived from routing protocols.