Fortinet FortiGate 30B - Manual (Page 21)

Configuring Configuring NAT mode
FortiGate-30B FortiOS 3.0 MR6 Install Guide
01-30006-0459-20080505
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4 Select OK.
5 Repeat this procedure for each interface as required.
Configure a DNS server
A DNS server is a service that converts symbolic node names to IP addresses. A
domain name server (DNS server) implements the protocol. In simple terms, it
acts as a phone book for the Internet. A DNS server matches domain names with
the computer IP address. This enables you to use readable locations, such as
fortinet.com when browsing the Internet.
DNS server IP addresses are typically provided by your internet service provider.
To configure DNS server settings
1 Go to System > Network > Options.
2 Enter the IP address of the primary DNS server.
3 Enter the IP address of the secondary DNS server.
4 Select Apply.
Adding a default route and gateway
A route provides the FortiGate unit with the information it needs to forward a
packet to a particular destination. A static route causes packets to be forwarded to
a destination other than the default gateway. You define static routes manually.
Static routes control traffic exiting the FortiGate unit-you can specify through
which interface the packet will leave and to which device the packet should be
routed.
In the factory default configuration, entry number 1 in the Static Route list is
associated with a destination address of 0.0.0.0/0.0.0.0, which means any/all
destinations. This route is called the "static default route". If no other routes are
present in the routing table and a packet needs to be forwarded beyond the
FortiGate unit, the factory configured static default route causes the FortiGate unit
to forward the packet to the default gateway.
Initial PADT Timeout Initial PPPoE Active Discovery Terminate (PADT) timeout in
seconds. Use this timeout to shut down the PPPoE session if it
is idle for this number of seconds. Your ISP must support
PADT. To disable the PADT timeout, set the value to 0.
Distance Enter the administrative distance, between 1 and 255 for the
default gateway retrieved from the DHCP server. The
administrative distance specifies the relative priority of a route
when there are multiple routes to the same destination. A
lower administrative distance indicates a more preferred route.
Retrieve default gateway
from server Enable to retrieve a default gateway IP address from the
DHCP server. The default gateway is added to the static
routing table.
Override internal DNS Enable to use the DNS addresses retrieved from the DHCP
server instead of the DNS server IP addresses on the DNS
page on System > Network > Options. On FortiGate-100
units and lower, you should also enable Obtain DNS server
address automatically in System > Network > Options.
Note: If you change the IP address of the interface you are connecting to, you must
connect through a web browser again using the new address. Browse to https:// followed by
the new IP address of the interface. If the new IP address of the interface is on a different
subnet, you may have to change the IP address of your computer to the same subnet.