Lightning SA MultiCom, User Manual, Page: 51 / 172

MultiCom Firewall User’s Manual 51
Special Configurations
Firewall itself)
• if the modem/ router is using IP addresses in the 10.0.0.0/255.0.0.0 subnet
then you will need to change the IP address and DHCP Server of the
Firewall’s LAN interface (because it uses this subnet by default.)
• if there is a router between the Firewall and the Modem then the router must
be configured correctly to reach the Internet through the Modem or some
other route
Option A: Broadband Modem is DHCP Server. The Broadband modem
receives all of the IP configuration directly from the ISP and uses its own
Network Address Translation to share the connection. In this case you can
simply plug in the MultiCom Firewall immediately between your network and
your xDSL, cable or wireless modem to use the default configuration. If the
Modem uses the 10.0.0.0/255.0.0.0 subnet then you will need to change the LAN
interface to a different subnet. For example you could configure the LAN
interface to use 192.168.0.1, subnet 255.255.255.0. If you change the IP address
of the LAN interface be sure to also change the IP addresses of the LAN’s DHCP
server, in this case to 192.168.0.17-192.168.0.117.
Option B: Static IP with Modem and Firewall. If the Broadband Modem does
not offer a DHCP server then you will need to use the Easy Setup’s Static IP
configuration to allow the MultiCom Firewall to reach it. Configure the WAN
interface of the Firewall to be on the same network as the Modem. For instance if
the Modem has an IP address of 192.168.0.1, subnet 255.255.255.0 then
configure the Firewall’s WAN IP address to be 192.168.0.2, subnet
255.255.255.0. The default gateway will be the IP address of the Modem, in this
example it is 192.168.0.1. The DNS parameters should be those of ISP.
Option C: Router between Modem and Firewall. In this case you will need to
use the Easy Setup’s Static IP configuration to allow the MultiCom Firewall to
reach the Router and the router must be configured to reach the Modem and/ or
Internet. Configure the WAN interface of the Firewall to be on the same network
as the router. For instance if the router has an IP address of 192.168.0.1, subnet
255.255.255.0 then configure the Firewall’s WAN IP address to be 192.168.0.2,
subnet 255.255.255.0. The default gateway will be the IP address of the router, in
this example it is 192.168.0.1. The DNS parameters should be those of ISP.
Option D: Router between Firewall and Local Network. In this case configure
the WAN interface using the Easy Setup for Internet Access. Then configure the
router to use the LAN interface of the MultiCom Firewall as the default gateway