Telecom Routers Switches Interview Question:

What are the differences between an Ethernet switch and a hub?

Submitted by: Administrator

In a hub, a frame is passed along or "broadcast" to every
one of its ports. It doesn't matter that the frame is only
destined for one port. The hub has no way of distinguishing
which port a frame should be sent to. Passing it along to
every port ensures that it will reach its intended
destination. This places a lot of traffic on the network
and can lead to poor network response times.

Additionally, a 10/100Mbps hub must share its bandwidth
with each and every one of its ports. So when only one PC
is broadcasting, it will have access to the maximum
available bandwidth. If, however, multiple PCs are
broadcasting, then that bandwidth will need to be divided
between all of those systems, which will degrade
performance.

A switch, on the other hand, keeps a record of the MAC
addresses of all the devices connected to it. With this
information, a switch can identify which system is sitting
on which port. So when a frame is received, it knows
exactly which port to send it to, which significantly
increases network response times. And, unlike a Hub, a
10/100Mbps switch will allocate a full 10/100Mbps to each
of its ports. So regardless of the number of PCs
transmitting, users will always have access to the maximum
amount of bandwidth. It's for these reasons
Submitted by: Administrator