Fortinet FortiGate FortiGate-50, Installation And Configuration Manual

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Fortinet Inc.
Configuring interfaces Network configuration
To change the MTU size of the packets leaving the external interface:
1 Go to System > Network > Interface .
2 For the external interface, select Modify .
3 Select Fragment outgoing packets greater than MTU.
4 Set the MTU size.
Set the maximum packet size in the range of 68 to 1500 bytes. The default MTU size
is 1500. Experiment by lowering the MTU to find an MTU size for best network
performance.
If you do not select Connect to PPPoE server, the FortiGate unit will not connect to a
PPPoE server. You can deselect this option if you are configuring the FortiGate unit
offline.
Configuring the management interface (Transparent mode)
In Transparent mode, you can configure the management interface for management
access to the FortiGate unit.
1 Go to System > Network > Management .
2 Change the Management IP and Mask as required.
This must be a valid address for the network from which you will manage the
FortiGate unit.
3 Add a default gateway IP address if the FortiGate unit must connect to a default
gateway to reach the management computer.
4 Select the management Access methods for each interface.
By default in Transparent mode, you manage the FortiGate unit by connecting to the
internal or dmz interface. However, you can configure the management interface so
that you can manage the FortiGate unit by connecting to any interface.
5 Select Apply to save your changes.
Note: If you connect to your ISP using DHCP to obtain an IP address for the external interface,
you cannot set the MTU below 576 bytes due to DHCP communication standards.
Note: You cannot set MTU size if the external interface is configured using PPPoE. The PPPoE
protocol configures optimum MTU size.
HTTPS To allow secure HTTPS connections to the web-based manager using the
management interface.
PING If you want the management interface to respond to pings. Use this setting to verify
your installation and for testing.
HTTP To allow HTTP connections to the web-based manager using the management
interface. HTTP connections are not secure and can be intercepted by a third party.
SSH To allow secure SSH connections to the CLI using the management interface.
SNMP To allow a remote SNMP manager to request SNMP information by connecting to
the management interface. See “Configuring SNMP” on page 106 .
TELNET To allow Telnet connections to the CLI using the management interface. Telnet
connections are not secure and can be intercepted by a third party.