Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual page 646

Understanding SNMPv3
Figure 36-1 SNMP Entity for Traditional SNMP Agents
UDP
Message Processing Subsystem
The message processing subsystem accepts outgoing PDUs from the dispatcher and prepares them for
transmission by wrapping them in a message header and returning them to the dispatcher. The message
processing subsystem also accepts incoming messages from the dispatcher, processes each message
header, and returns the enclosed PDU to the dispatcher. An implementation of the message processing
subsystem may support a single message format corresponding to a single version of SNMP (SNMPv1,
SNMPv2c, SNMPv3), or it may contain a number of modules, each supporting a different version of
SNMP.
Security Subsystem
The security subsystem authenticates and encrypts messages. Each outgoing message is passed to the
security subsystem from the message processing subsystem. Depending on the services required, the
security subsystem may encrypt the enclosed PDU and some fields in the message header. In addition,
the security subsystem may generate an authentication code and insert it into the message header. After
encryption, the message is returned to the message processing subsystem.
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
36-8
IPX Other
Dispatcher
Transport Mapping
Message Dispatcher
PDU Dispatcher
Proxy
foward
applications
MIB Instrumentation
SNMP Entity
Message Processing
Subsystem
v1MP
v2c MP
v3MP
otherMP
Command Notification
responder
applications applications
Chapter 36
SNMP Engine
Security Access Control
Subsystem Subsystem
User-based View-based
security access control
model
Other
access control
security
model
originator
SNMP Applications
Configuring SNMP
model
Other
model
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