D-Link NetDefend DFL-1660, Руководство пользователя

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Maximum Loss A single host is considered unreachable if this number of
consecutive ping responses to that host are not replied to.
Grace Period Do not allow the link monitor to trigger an action for this
number of seconds after the last reconfiguration. This avoids
false positives during initial link negotiation. The default
value is 45 seconds.
Send from Shared IP Address This option only appears in an HA cluster and should be used
if individual public IPv4 addresses are not available to the
devices in a cluster.
2.4.2. SNMP Monitoring
Overview
Simple Network Management Protocol (SNMP) is a standardized protocol for management of
network devices. An SNMP compliant client can connect to a network device which supports the
SNMP protocol to query and control it.
NetDefendOS supports SNMP version 1 and version 2. Connection can be made by any SNMP
compliant clients to devices running NetDefendOS. However, only query operations are permitted
for security reasons. Specifically, NetDefendOS supports the following SNMP request operations by
a client:
• The GET REQUEST operation
• The GET NEXT REQUEST operation
• The GET BULK REQUEST operation (SNMP Version 2c only)
The NetDefendOS MIB
The Management Information Base (MIB) is a database, usually in the form of a text file, which
defines the parameters on a network device that an SNMP client can query or change. The MIB file
for a device running NetDefendOS is distributed with the standard NetDefendOS distribution pack
as a file with the name DFLNNN-TRAP.MIB (where NNN indicates the model number of the
firewall).
This MIB file should be transferred to the hard disk of the workstation that will run the SNMP client
so it can be imported by the client software. When the SNMP client runs, the MIB file is read and
tells the client which values can be queried on a NetDefendOS device.
Defining SNMP Access
SNMP access is defined through the definition of a NetDefendOS Remote object with a Mode value
of SNMP. The Remote object requires the entry of:
• Interface - The NetDefendOS interface on which SNMP requests will arrive.
• Network - The IP address or network from which SNMP requests will come.
• Community - The community string which provides password security for the accesses.
The Community String
2.4.2. SNMP Monitoring Chapter 2. Management and Maintenance
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