Gateway vs. routers vs. bridges

Question

Explain the followīng sentences with an example ?

A). "Bridge is used to connect different LAN's in the same network"

B). "Router is used to connect different similar networks"

C). "Gateway is used to connect different dissimilar networks"

Comments

A). "Bridge is used to connect different LAN's in the same network"

Brides are used to connecting two different LANs in the same network. for knowing this, we should the basics of bridges. A bridge is a Layer-2 device, it works on a physical as well as data link layer, it can look into the MAC addresses by looking into the frames and based on that it will forward the packets.

Now the thing Bridges does not know about IP addresses, so if we have to talk to other networks, we must have the IP address of that So bridges can never be used to connect LANs in a different network.

Eg: we can connect Ethernet to the token ring via bridges or Ethernet to WiFi etc..within same network only

B) "Router is used to connect different similar networks"

Yes, we know that Router is a Layer 3 device, It can look the IP addresses and make several decisions. It is used to connect two different similar networks..

for eg: we connect one TCP/IP network to the other TCP/IP network and one ATM networks to the other  ATM network etc..

The drawback of the router is, we cannot connect two different Networks, I mean we can not connect ATM networks to TCP/IP networks that why Gateways are evolved..

C). "Gateway is used to connect different dissimilar networks"

Yes, Gateway has all the layers present in it. It is used to connect two different dissimilar networks.

we can connect TCP/IP networks to ATM. networks..;