Fortinet 100A - Manual (Page 53)

System network Configuring interfaces
FortiGate-100A Administration Guide 01-28007-0068-20041203
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MTU
To improve network performance, you can change the maximum transmission unit
(MTU) of the packets that the FortiGate unit transmits from any interface. Ideally, this
MTU should be the same as the smallest MTU of all the networks between the
FortiGate unit and the destination of the packets. If the packets that the FortiGate unit
sends are larger, they are broken up or fragmented, which slows down transmission.
Experiment by lowering the MTU to find an MTU size for best network performance.
To change the MTU, select Override default MTU value (1500) and enter the
maximum packet size. For manual and DHCP addressing mode the MTU size can be
from 576 to 1500 bytes. For PPPoE addressing mode the MTU size can be from 576
to 1492 bytes.
Log
Select Log to record logs for any traffic to or from the interface. To record logs you
must also enable traffic log for a logging location and set the logging severity level to
Notification or lower. Go to Log & Report > Log Config to configure logging locations
and types. For information about logging see
“Log & Report” on page 339 .
Configuring interfaces
Use the following procedures to configure FortiGate interfaces and VLAN
subinterfaces.
• To bring down an interface that is administratively up
• To add interfaces to a zone
• To add an interface to a virtual domain
• To change the static IP address of an interface
• To configure an interface for DHCP
• To configure an interface for PPPoE
• To add a secondary IP address
• To configure support for dynamic DNS services
• To add a ping server to an interface
• To control administrative access to an interface
• To change the MTU size of the packets leaving an interface
• To configure traffic logging for connections to an interface
SSH To allow SSH connections to the CLI through this interface.
SNMP To allow a remote SNMP manager to request SNMP information by connecting to
this interface. See “Configuring SNMP” on page 98 .
TELNET To allow Telnet connections to the CLI through this interface. Telnet connections
are not secure and can be intercepted by a third party.
Note: In Transparent mode, if you change the MTU of an interface, you must change the MTU
of all interfaces to match the new MTU.