Fortinet FortiGate 4000 User Manual

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164
Fortinet Inc.
Configuring DHCP services
Network configuration
You can add multiple scopes to an interface so that the DHCP server added to that 
interface can supply IP addresses to computers on multiple subnets.
Add multiple scopes if the DHCP server receives DHCP requests from subnets that 
are not connected directly to the FortiGate unit. In this case, the DHCP requests are 
sent to the FortiGate unit through DHCP relay. DHCP relay packets contain DHCP 
relay IP, which is the IP address of the subnet from which the DHCP relay received the 
request.
If the DHCP request received by the DHCP server is not forwarded by a DHCP relay, 
the DHCP server decides which scope to use based on the IP address of the interface 
that received the DHCP request; usually the scope with the same subnet as the 
interface.
If the DHCP request received by the server is forwarded by a DHCP relay, the relay IP 
is used to select the scope.
To add a scope to a DHCP server
1
Go to System > Network > DHCP.
2
Select Address Scope. 
3
Select an interface.
You must configure the interface as a DHCP server before it can be selected.
4
Select New to add an address scope.
5
Configure the address scope.
6
Select Advanced if you want to configure Advanced Options.
7
Select OK.
Scope Name
Enter the address scope name. 
IP Pool
Enter the starting IP and ending IP for the range of IP addresses that this 
DHCP server assigns to DHCP clients. 
Netmask
Enter the netmask that the DHCP server assigns to the DHCP clients.
Lease Duration
Enter the interval, in days, hours and minutes, after which a DHCP client 
must ask the DHCP server for a new address. 
If you select Unlimited, DHCP leases never expire. 
Domain
Optionally enter in the domain that the DHCP server assigns to the DHCP 
clients.
Default Route
Enter the default route to be assigned to DHCP clients. The default route 
must be on the same subnet as the IP pool.
DNS IP
Enter the addresses of up to 3 DNS servers that the DHCP server assigns 
to the DHCP clients. 
WINS Server IP  Add the IP addresses of one or two WINS servers to be assigned to DHCP 
clients.
Exclusion Range Optionally enter up to 4 exclusion ranges of IP addresses within the IP pool 
that cannot be assigned to DHCP clients.