Hello Can someone tell me what collision domain does in a LAN. I think it is when you send a message to a computer and the networking will send it to all computers connected to the LAN and LANS connected to that. Not sure if that is right or not. Thanks in advance Steve

A collision is when two computers on the same Ethernet network node try to send data at the same time. As the network can only carry data from one computer at a time, a collision occurs. When this happens, both computer back off and wait a random period and retransmit. The ransom period will only be a few milli seconds but enough for one computer to get its data in while the other waits. A collission domain is an area where a particular group of computers are likely to have collisions. I think you might be refering to a question earlier when somebody was discussing the relative merits of Switches and hubs where the collision domain of switches is smaller than that of a hub. This is because with a switch only any two computers on the network are likely to collide, the sender and the reciever. While with a hub any computer connected to the hub is likely to collide. Collision detection and avoidance is a whole specialised subject in itself. Hope this explains it a little bit. Stuart

Thanks for you help, that explain a lot to me. Thanks