LAYER 2 VS. LAYER 3 NETWORKS



When the network gets large enough, the broadcast traffic begins to create congestion and decreases network efficiency. Anything transmitted Dedicated Servers in USA by one device is forwarded to all devices. Layer 2 networks forward all traffic, especially ARP and DHCP broadcasts.
Bridges forward broadcasts between two connected networks until they have located all hosts. Devices used on a Layer 2 Ethernet network Web hosting include network interface cards, hubs, bridges and switches. A switch works with MAC addresses at layer 2 of the OSI 7 layer model. Switches forward broadcast traffic only when it doesn’t know where a host is. The address of a computer can only be changed if the network interface card is changed. None of these devices have to disassemble or reassemble data, only forward it. Ethernet devices use ‘burned in’ MAC addresses to identify each host. Layer 2 networks are connected together using hubs, bridges and switches. Hubs take each frame that is received and send duplicate frames simultaneously out all other ports. These addresses are attached to network interface cards and cannot be changed. Because nothing is done to the data along the way, layer 2 networks are often considered to be ‘faster’ than a layer 3 network.
This requires stripping off the datalink layer frame information. All of this takes extra time. Dedicated Servers in USA In an IP layer 3 network, the IP portion of the datagram has to be read. Layer 3 networks are built to run on on layer 2 networks. A Layer 3 switch is a high-performance device for network routing. Once the protocol frame information is stripped, the IP datagram has to be reassembled. A router works with IP addresses at layer 3 of the model. Once the IP datagram is reassembled, the hop count has to be decremented, the header checksum has to be recalculated, a lookup for routing must be made, and only then can the IP datagram be chopped back up and inserted into frames and transmitted to the next hop.
By contrast, layer 3 devices restrict broadcast traffic such as ARP and DHCP broadcasts to the local network. This reduces overall traffic levels by allowing administrators to chop networks into smaller parts and restrict broadcasts to only that sub-network. A layer 3 network, prperly configured, can grow to any size Dedicated Servers in USA . This means there is a limit to the size of a layer 2 network.
LAYER 3 NETWORKS
LAYER 2 NETWORKS