142

 

 

AT-TQ2403 - Management Software - User's Guide

 

 

 

 

 

 

 

 

 

 

 

Field

 

Description

 

 

Restrict the source of SNMP

 

You can restrict the source of permitted SNMP requests.

 

 

requests to only the

 

 

 

 

designated hosts or subnets

 

∙ To restrict the source of permitted SNMP requests, click

 

 

 

 

Enabled.

 

 

 

 

∙ To permit any source submitting an SNMP request, click

 

 

 

 

Disabled.

 

 

 

 

 

 

 

Hostname or subnet of

 

Specify the DNS hostname or subnet of the machines that can

 

 

Network Management

 

execute GET and SET requests to the managed devices.

 

 

System

 

As with community names, this provides a level of security on SNMP

 

 

 

 

 

 

 

 

settings. The SNMP agent will only accept requests from the

 

 

 

 

hostname or subnet specified here.

 

 

 

 

To specify a subnet, enter one or more subnetwork address ranges in

 

 

 

 

the form AddressRange/MaskLength where AddressRange is an IP

 

 

 

 

address and MaskLength is the number of mask bits. Both formats

 

 

 

 

NetAddress/NetMask and NetAddress/MaskLength are supported.

 

 

 

 

Individual hosts can be provided for this, i.e. I.P Address or Hostname.

 

 

 

 

For example, if you enter a range of 192.168.1.0/24 this specifies a

 

 

 

 

subnetwork with address 192.168.1.0 and a subnet mask of

 

 

 

255.255.255.0.

 

 

 

 

The address range is used to specify the subnet of the designated

 

 

 

 

NMS. Only machines with IP addresses in this range are permitted to

 

 

 

 

execute GET and SET requests on the managed device. Given the

 

 

 

 

example above, the machines with addresses from 192.168.1.1

 

 

 

 

through 192.168.1.254 can execute SNMP commands on the device.

 

 

 

 

(The address identified by suffix .0 in a subnetwork range is always

 

 

 

 

reserved for the subnet address, and the address identified by .255 in

 

 

 

 

the range is always reserved for the broadcast address).

 

 

 

 

As another example, if you enter a range of 10.10.1.128/25 machines

 

 

 

 

with IP addresses from 10.10.1.129 through 10.10.1.254 can execute

 

 

 

 

SNMP requests on managed devices. In this example, 10.10.1.128 is

 

 

 

 

the network address and 10.10.1.255 is the broadcast address. 126

 

 

 

 

addresses would be designated.

 

 

 

 

 

 

Configuring SNMP Traps

SNMP Traps facilitate asynchronous communication of messages from SNMP managed devices (like the AT-TQ2403 Management Software) to designated hosts. If a Network Management System (NMS) is responsible for monitoring a large number of devices on a network, it is not practical to periodically query every device on the network. By enabling SNMP event traps on the AP, individual devices can send messages directly to SNMP Managers or to other designated hosts on the NMS regarding some network events, such as network interfaces going up or down, clients failing to associate or authenticate with the access point, system power up or down and changes in the network topology.

SNMP traps save on network resources by eliminating redundant SNMP requests. They also make it easier for SNMP Managers to troubleshoot their network. For example, if an SNMP manager is responsible for a large network that supports many devices, and each device has a large number of objects, it is impractical to request information from every object on every device. The optimum solution is for each agent on the managed device to notify the manager of any unusual events. It does this