Can a router act as a switch?

.Instead of spending $- to purchase a brand new switch of comparable build quality to your old Wi-Fi router, it makes financial sense (and is environmentally friendly) to invest five minutes of your time tweaking the settings on the old router to turn it from a Wi-Fi access point and routing tool into a network switch–perfect for dropping behind your entertainment center so that your DVR, Xbox, and media center computer can all share an Ethernet connection.

Switches work on layer 2, which uses MAC addresses to identify hosts. A switch can only move frames to another host on that switch. There is an assumption that when you send frames to a MAC address, that it is on the same medium as yourself.

Routers work on layer 3, which uses IP addresses to identify hosts.

IP packets are independent of a medium; addresses not in private ranges are meant to be globally reachable. Layer 3 has the notion of a network to allow it not to care about the actual medium (or anything Layer 2 does).

Obviously though, you have local neighbors (on your switch, for example, or associated to your wireless AP) that are reachable directly, and then hosts you probably want to talk to outside of your network. Thus, the concept of a router or forwarder is needed. Hosts in the same network can reach each other directly, if they are not in the same network, then one or more routers need to hand off traffic between networks.

So routers do not send data to all computers on the network, but forward traffic between networks.

A multilayer switch also called L3 switch can perform the functions of a switch as well as that of a router at incredibly fast speeds

Some of the Modals of cisco MLS switches:3550,3560,3750,4500,6500,7000

YES, router maintain 3rd level of the network layer and switch maintain the 2nd lavel of the network layer. so router can do what switch can but switch can't do all what router can.

YES in the modular and also in some non modular router series..

Yes but some type of Router

Yes possible in managable switch

yes advance devices provide this facility.

yes in some models it is possible.

Yes, special switches can act as switch and a router