hub vs switch

Hi all,

these are the differences between hub and switch , which i have read
in the book, "A practical guide to Ubuntu Linux", is there any other
point important points which the book book has not mentioned

Hub

A hub (sometimes called a concentrator) is a device that connects
systems so they are all part of one network segment and share the
network bandwidth. Hubs work at the physical layer of the IP and OSI
models (layer 1).

A nonswitched (hub-based) broadcast network can run in only half-
duplex mode.

Switch

A switch connects network segments. A switch inspects each data packet
and learns which devices are connected to which of its ports. The
switch sorts packets and sends each packet only to the device it is
intended for. Because a switch sends packets only to their destination
devices, it can conserve network bandwidth and perform better than a
hub. A switch may have buffers for holding and queuing packets.
Switches work at the data link layer of the IP and OSI models (layer
2 ).

Some Ethernet switches have enough bandwidth to communicate
simultaneously, in full-duplex mode, with all connected devices. Full-
duplex Ethernet further improves things by eliminating collisions.
Theoretically, each host on a switched network can transmit and
receive simultaneously at speed of the network (e.g., 100 megabits per
second) for an effective bandwidth between hosts of twice the speed of
the network (e.g., 200 megabits per second), depending on the capacity
of the switch.

annalissa wrote:
> Hi all,
>
> these are the differences between hub and switch , which i have read
> in the book, "A practical guide to Ubuntu Linux", is there any other
> point important points which the book book has not mentioned
>
> Hub
>
> A hub (sometimes called a concentrator) is a device that connects
> systems so they are all part of one network segment and share the
> network bandwidth. Hubs work at the physical layer of the IP and OSI
> models (layer 1).
>
> A nonswitched (hub-based) broadcast network can run in only half-
> duplex mode.
>
> Switch
>
> A switch connects network segments. A switch inspects each data packet
> and learns which devices are connected to which of its ports. The
> switch sorts packets and sends each packet only to the device it is
> intended for. Because a switch sends packets only to their destination
> devices, it can conserve network bandwidth and perform better than a
> hub. A switch may have buffers for holding and queuing packets.
> Switches work at the data link layer of the IP and OSI models (layer
> 2 ).
>
> Some Ethernet switches have enough bandwidth to communicate
> simultaneously, in full-duplex mode, with all connected devices. Full-
> duplex Ethernet further improves things by eliminating collisions.
> Theoretically, each host on a switched network can transmit and
> receive simultaneously at speed of the network (e.g., 100 megabits per
> second) for an effective bandwidth between hosts of twice the speed of
> the network (e.g., 200 megabits per second), depending on the capacity
> of the switch.
>


One of the uses of a hub is bandwidth monitoring. Its very easy to
connect computers together using a hub, and have a third computer
monitor the transfer.

On Oct 3, 10:47 pm, Maxwell Lol <nos...@com.invalid> wrote:
> Carl <c...@never.com> writes:
> > One of the uses of a hub is bandwidth monitoring. Its very easy to
> > connect computers together using a hub, and have a third computer
> > monitor the transfer.
>
> As an alternative, you can get a switch with "port mirroring"
> capability. You can configure one of the ports to mirror all of the
> packets seen on the other ports.
>
> Dell makes one for just $100 (8 ports) to $400 (48 ports).

-Using any kind of switches you can monitor the traffic even if has
not the "port mirroring" function. Using ARP spoofing. Many
applications on both Linux and Windows will help doing so easily. You
can also do this manually on Linux. If you want example on Windows you
can check a program called winarpspoof . It's a free ware and will
help you to monitor the whole network without using the "port
mirroring" capability. But this is forbidden to do on some networks
specially if you are not the dmin for the network. So every body
should check first.
Regards,

On Oct 3, 10:47 pm, Maxwell Lol <nos...@com.invalid> wrote:
> Carl <c...@never.com> writes:
> > One of the uses of a hub is bandwidth monitoring. Its very easy to
> > connect computers together using a hub, and have a third computer
> > monitor the transfer.
>
> As an alternative, you can get a switch with "port mirroring"
> capability. You can configure one of the ports to mirror all of the
> packets seen on the other ports.
>
> Dell makes one for just $100 (8 ports) to $400 (48 ports).

-Using any kind of switches you can monitor the traffic even if has
not the "port mirroring" function. Using ARP spoofing. Many
applications on both Linux and Windows will help doing so easily. You
can also do this manually on Linux. If you want example on Windows you
can check a program called winarpspoof . It's a free ware and will
help you to monitor the whole network without using the "port
mirroring" capability. But this is forbidden to do on some networks
specially if you are not the admin for the network. So every body
should check first.
Regards,