Snmp traps – Netopia 4553 User Manual
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Monitoring Tools 12-189
2.
Select System Location and enter the router’s physical location (room, floor, building, etc.).
3.
Select System Contact and enter the name of the person responsible for maintaining the router.
System Name, System Location, and System Contact set the values returned by the Netopia 4553 SNMP agent
for the SysName, SysLocation, and SysContact objects, respectively, in the MIB II system group. Although
optional, the information you enter in these items can help a system administrator manage the network more
efficiently.
Community strings
The Read-Only Community String and the Read/Write Community String are like passwords that must be used
by an SNMP manager quer ying or configuring the Netopia 4553. An SNMP manager using the Read-Only
Community String can examine statistics and configuration information from the router, but cannot modify the
router’s configuration. An SNMP manager using the Read/Write Community String can both examine and
modify configuration parameters.
By default, the read-only and read/write community strings are set to public and private, respectively. You
should change both of the default community strings to values known only to you and trusted system adminis-
trators.
To change a community string, select it and enter a new value.
Star ting with the version 4.3 firmware, setting the Read-Only and Read-Write community strings to the empty
string will block all SNMP requests to the router. (The router may still send SNMP Traps if those are properly
enabled.)
Previously, if either community string was the empty string, SNMP Requests specifying an empty community
string were accepted and processed.
This change is designed to allow the administrator to block SNMP access to the router and to provide more
granular control over the allowed SNMP operations to the router.
■
Setting only the Read-Write community string to the empty string will block SNMP Set Requests to the
router, but Get Requests and Get-Next Requests will still be honored using the Read-Only community string
(assuming that is not the empty string).
■
Setting only the Read-Only community string to the empty string will not block Get Requests or Get-Next
Requests since those operations (and Set Requests) are still allowed using the (non-empty) Read-Write
community string.
Even if you decide not to use SNMP, you should change the community strings. This prevents unauthorized
access to the Netopia 4553 through SNMP. For more information on security issues, see
.
SNMP traps
An SNMP trap is an informational message sent from an SNMP agent (in this case, the Netopia 4553) to a
manager. When a manager receives a trap, it may log the trap as well as generate an aler t message of its own.
Standard traps generated by the Netopia 4553 include the following:
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An authentication failure trap is generated when the router detects an incorrect community string in a
received SNMP packet. Authentication Traps Enable must be On for this trap to be generated.