Avaya C360 - Manual (Page 74)

Establishing Switch Access
74 Installation and Configuration Guide Avaya C360 Multilayer Stackable Switches, version 4.5
● 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.
● 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 enable or disable a port.
● 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
specified 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.
SNMPv1
SNMPv1 uses community strings to limit access rights. Each SNMP device is assigned to a
read community and a read-write community. To communicate with a switch, you must send an
SNMP packet with the relevant community name.
By default, if you communicate with a switch 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 cannot change any of the values in
the MIB tree.
If you communicate with a switch using the write community, you are assigned the security
name "WriteCommN". This security name is mapped to the "WriteComm" group by default. This
allows you to view the agent's MIB tree and change any of the values in the MIB tree.
!
CAUTION:
CAUTION:
If you delete the ReadCommN or WriteCommN users, the ReadCommG or
WriteCommG groups, or the SNMPv1View you may not be able to access the
switch using SNMPv1.
In addition, traps are sent to designated trap receivers. Packets with trap information also
contains a trap community string.
SNMPv2c
SNMPv2c is very similar to SNMPv1. However, SNMPv2c adds support for the get-bulk action
and supports a different trap format.