Netopia 3346N-ENT User Guide (en)

Monitoring Tools   9-11
Setting the Read-Only and Read-Write community strings to the empty string will block all SNMP requests to the 
gateway. (The gateway 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 gateway and to provide more 
granular control over the allowed SNMP operations to the gateway.
Setting only the Read-Write community string to the empty string will block SNMP Set Requests to the 
gateway, 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 Router 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 Router) 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 Netopia Firmware Version 8.6.1 include the following:
An authentication failure trap is generated when the gateway detects an incorrect community string in a 
received SNMP packet. Authentication Traps Enable must be On for this trap to be generated.
A cold star t trap is generated after the gateway is reset.
An inter face down trap (ifDown) is generated when one of the gateway’s inter faces, such as a por t, stops 
functioning or is disabled.
An inter face up trap (ifUp) is generated when one of the gateway’s inter faces, such as a por t, begins 
Netopia Firmware Version 8.6.1 sends traps using UDP (for IP networks). 
You can specify which SNMP managers are sent the IP traps generated by the Netopia Firmware Version 8.6.1. 
Up to eight receivers can be set. You can also review and remove IP traps.
To go to the IP Trap Receivers screen, select IP Trap Receivers. The IP Trap Receivers screen appears.