B. DHCP - automatic configuration
All the required IP addresses for Internet connection can, alternatively, be automatically retrieved
from an ISP's DHCP server by enabling the DHCP Client option for the interface connected to the
ISP. We enable this option by first selecting Ethernet > Interfaces in the navigation tree to
display a list of all the interfaces.
Click the
ge2
interface in the list to display its properties.
In the above screenshot, DHCP is enabled for this interface and this is the required setting if IP
addresses are to be retrieved automatically. Usually, a DHCP
Host Name
does not need to be
specified but can sometimes be used by an ISP to uniquely identify this Clavister Security
Gateway as a particular DHCP client to the ISP's DHCP server.
On connection to the ISP, all required IP addresses are retrieved automatically from the ISP via
DHCP and CorePlus automatically sets the relevant address objects in the address book with this
information.
For CorePlus to know on which interface to find the public Internet, a
route
has to be added to
the
main
CorePlus routing table which specifies that the network
all-nets
can be found on the
interface connected to the ISP and this route must also have the correct
Default Gateway
IP
address specified. This
all-nets
route is added automatically by CorePlus during the DHCP
address retrieval process.
After all IP addresses are set via DHCP and an
all-nets
route is added, the connection to the
Internet is configured but no traffic can flow to or from the Internet since there is no IP rule
defined that allows it. As was done in the previous option (A) above, we must therefore define an
IP rule that will allow traffic from a designated source interface and source network. (in this
example, the network
ge3_net
and interface
ge3
) to flow to the destination network
all-nets
and
the destination interface
ge2
.
C. PPPoE setup
For PPPoE connection, we must create a PPPoE tunnel interface associated with the physical
Ethernet interface. Assume that the physical interface is
ge2
and the PPPoE tunnel object created
is called
wan_pppoe
. Go to Interfaces > PPPoE in the navigation tree and select Add > PPPoE
Tunnel. These values can now be entered into the PPPoE Tunnel properties dialog.
Chapter 3: CorePlus Configuration
44