User Manual

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Users Manual of XGS-6350-24X4C
management side and agent.
SNMP management side can be part of the network management system (NMS, like CiscoWorks). Agent and
MIB are stored on the system. You need to define the relationship between network management side and
agent before configuring SNMP on the system.
SNMP agent contains MIB variables. SNMP management side can check or modify value of these variables.
The management side can get the variable value from agent or stores the variable value to agent. The agent
collects data from MIB. MIB is the database of device parameter and network data. The agent also can
respond to the loading of the management side or the request to configure data. SNMP agent can send trap
to the management side. Trap sends alarm information to NMS indicating a certain condition of the network.
Trap can point out improper user authentication, restart, link layer state(enable or disable), close of TCP
connection, lose of the connection to adjacent systems or other important events.
a) SNMP notification
When some special events occur, the system will send ‘inform’ to SNMP management side. For example,
when the agent system detects an abnormal condition, it will send information to the management side.
SNMP notification can be treated as trap or inform request to send. Since the receiving side doesn’t send any
reply when receiving a trap, this leads to the receiving side cannot be sure that the trap has been received.
Therefore the trap is not reliable. In comparison, SNMP management side that receives “inform request” uses
PDU that SNMP echoes as the reply for this information. If no “inform request” is received on the
management side, no echo will be sent. If the receiving side doesn’t send any reply, then you can resend the
“inform request”. Then notifications can reach their destination.
Since inform requests are more reliable, they consume more resources of the system and network. The trap
will be discarded when it is sent. The “inform request” has to be stored in the memory until the echo is
received or the request timeouts. In addition, the trap is sent only once, while the “inform request” can be
resent for many times. Resending "inform request" adds to network communications and causes more load
on network. Therefore, trap and inform request provide balance between reliability and resource. If SNMP
management side needs receiving every notification greatly, then the “inform request” can be used. If you give
priority to the communication amount of the network and there is no need to receive every notification, then
trap can be used.
This switch only supports trap, but we provide the extension for "inform request".
b) SNMP version
System of our company supports the following SNMP versions:
 SNMPv1---simple network management protocol, a complete Internet standard,which is defined in
RFC1157.
 SNMPv2C--- Group-based Management framework of SNMPv2, Internet test protocol, which is defined
in RFC1901.
Layer 3 switch of our company also supports the following SNMP:
 SNMPv3--- a simple network management protocol version 3, which is defined in RFC3410.