Snmp Versions; Snmpv1 Snmpv2C Snmpv3 - Avaya G350 Administration

Configuring SNMP

SNMP versions

•
Retrieve the value immediately after the variable you name — a get-next action.
The SNMP manager retrieves values from the MIB tree. Using the get-next function, you do not
need to know the exact variable name you are looking for. The SNMP manager takes the variable
you name and then uses a sequential search to find the desired variable.
•
Retrieve a number of values — a get-bulk action.
The get-bulk operation retrieves the specified number of instances of the requested MIB variable.
This minimizes the number of protocol exchanges required to retrieve a large amount of data.
NOTE:
Get-bulk is not supported in SNMPv1.
•
Change a setting on the agent — a set action.
The SNMP manager requests the agent to change the value of the MIB variable. For example, you
can run a script or an application on a remote device with a set action.
•
An agent can send an unsolicited message to the manager at any time if a significant,
predetermined event takes place on the agent. This message is called a trap.
When a trap condition occurs, the SNMP agent sends an SNMP trap message to the device
specified as the trap receiver or trap host. The SNMP Administrator configures the trap host,
usually the SNMP management station, to perform the action needed when a trap is detected.
NOTE:
For a list of traps and MIBS, see
SNMP versions
There are currently three versions of SNMP:
•
SNMPv1
•
SNMPv2c
•
SNMPv3
The Avaya G350 Media Gateway supports all three of these versions. The implementation of SNMPv3
on the G350 is backwards compatible. An agent that supports SNMPv3 will also support SNMPv1 and
SNMPv2c.
SNMPv1
SNMPv1 uses community strings to limit access rights. Each SNMP device is assigned to a read
community and a write community. To communicate with a device, you must send an SNMP packet with
the relevant community name.
By default, if you communicate with a device using only the read community, you are assigned the
security name ReadCommN. This security name is mapped to the ReadCommG group by default. This
allows you to view the agent's MIB tree, but you cannot change any of the values in the MIB tree.
98
Traps and MIBs on page 191.
Administration of the Avaya G350 Media Gateway
June 2004