Securing a LAN

I have a LAN configured with private IP adresses and a machine doing nat to
go out to the Internet. I have a DHCP configured in the gateway, and I have
an Ethernet network. I would like to add some authentication in this
network, now anyone can go there plug a cable in the hub an the dhcp will
assign him an ip address and will be able to use the Internet, this maybe is
not feasible with an Ethernet but it is with a Wi-Fi access network.

I think that with DHCP is possible to filter by MAC address only giving an
IP to a certain MAC, but I heard something about RADIUS, that is a server
used for authentication, I actually have no idea about what is a RADIUS and
how to configure it, but I would like some information about which are the
extra functionalities that RADIUS provide over a simple filtering by MAC
address and some clues to start learning about it.

Thanks a lot

Daniel Camps <(E-Mail Removed)> wrote:
> I have a LAN configured with private IP adresses and a machine doing nat to
> go out to the Internet. I have a DHCP configured in the gateway, and I have
> an Ethernet network. I would like to add some authentication in this
> network, now anyone can go there plug a cable in the hub an the dhcp will
> assign him an ip address and will be able to use the Internet, this maybe is
> not feasible with an Ethernet but it is with a Wi-Fi access network.
>
> I think that with DHCP is possible to filter by MAC address only giving an
> IP to a certain MAC, but I heard something about RADIUS, that is a server
> used for authentication, I actually have no idea about what is a RADIUS and
> how to configure it, but I would like some information about which are the
> extra functionalities that RADIUS provide over a simple filtering by MAC
> address and some clues to start learning about it.

What you're looking for is 802.1X authentication. A google search should turn
up ample documentation on it. Note that it's pretty uncommon for consumer
grade ethernet switches to support 1X authentication.

--
Frank Sweetser fs at wpi.edu
WPI Network Engineer
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