broadcast domain

gojericho0

I understand if there is a router seperating two subnets, each subnet will have its own broadcast domain because broadcasts do not get forwarded outside the subnet or network. If each subnet however only had hubs attatched to the router connecting the nodes would the network have just one collision domain since the router only looks at the ip address portion of the packet and not care about the mac address portion? or would there be two collision domains, one on each subnet?

Webmaster

There will be two colissions domains... electrical signals on the one subnet cannot colide with signals on the other subnet.

Read the following entirely to get a better understanding:
www.techexams.net/technotes/networkplus/networkcomponents.shtml

Also check out this post:
www.techexams.net/forums/viewtopic.php?t=4896

gojericho0

thanks for the help

gojericho0

would it be due to cost or protocal your network is using not just to use routers instead of bridges or switches since it would create both collision and broadcast domains?

Webmaster

Creating colission and broadcast domains is not always the primary reason for installing a network device. You would choose to use a particular device (router, bridge, switch) for different reasons (i.e. interconnect LANs into a WAN (router), segment networks (switches), extend networks (bridges).

Again, I recommend you read the TechNotes I linked to in my previous post, it explains the function of each device and how it relates to colission and broadcast domains.

x_Danny_x

my book says "contention domains", that is the same as your "collision domain" description. That is one of the reasons why I got confused in the early going but the "collision domain" word is the one that is going to be seen in the test right?

Webmaster

yeah, colission domain is far more common. Contention refers to the fact they all the nodes in the same colission domain content for the same media. The nodes compete with each other to get access to the medium (i.o.w. to be allowed to place electrical signals on the cable, i.o.w. to send traffic)