Controlling management access to the external interface
Use the following procedure to control management access to the DFL-500 through the external interface.
You can configure the DFL-500 so that you can access the web-based manager and CLI by connecting to the
external interface. You can also control whether a remote SNMP manager can connect to the external
interface to download management information from the DFL-500.
·
Go to
System > Network > Interface
.
·
For the external interface, select Modify
.
·
Check or uncheck the following Access parameters for the external interface:
HTTPS
To allow secure HTTPS connections to the web-based manager through the external interface.
PING
If you want the external interface to respond to pings. Use this setting to verify your installation and for
testing.
SSH
To allow secure SSH connections to the CLI through the external interface.
SNMP
To allow a remote SNMP manager to request SNMP information by connecting to the external interface.
See
.
Checking HTTPS for the external interface allows remote administration of the DFL-500 using the web-based
manager from any location on the Internet. Checking SSH for the external interface allows remote
administration of the DFL-500 using the CLI from any location on the Internet. Checking SNMP for the
external interface allows remote SNMP management of the DFL-500 from the Internet.
·
Select OK.
You can control the IP addresses from which administrators can access the web-based manager. See
editing administrator accounts
.
Changing external interface MTU size to improve network performance
To improve the performance of your internet connection, you can adjust the maximum transmission unit (MTU)
of the packets that the DFL-500 transmits from its external interface. Ideally, you want this MTU to be the
same as the smallest MTU of all the networks between the DFL-500 and the Internet. If the packets the DFL-
500 sends are larger, they get broken up or fragmented, which slows down transmission speeds.
Trial and error is the only sure way of finding the optimal MTU, but there are some guidelines that can help.
For example, the MTU of many PPP connections is 576, so if you connect to the Internet via PPP or PPPoE,
you might want to set the MTU size to 576. DSL modems may also have small MTU sizes. Most ethernet
networks have an MTU of 1500.
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.
To change the MTU size of the packets leaving the external interface:
·
Go to
System > Network > Interface
.
·
For the external interface, select Modify
.
·
Select Fragment outgoing packets greater than MTU.
·
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.
DFL-500 User Manual
118
