Specifications

© 2006 Cisco Systems, Inc.
All rights reserved.
Introduction 1-15
NAM / Traffic Analyzer v3.5 Tutorial
© 2006 Cisco Systems, Inc. All rights reserved.
Introduction 1-15
NAM / Traffic Analyzer v3.5 Tutorial
Network Performance Monitoring
Understanding the Basics
Network Performance Monitoring
Understanding the Basics
GAUGEs
TIMERs
0 9 1 2 3
COUNTERs TABLEs
FILEs
Operating System Data Structures
Manageable Switch or Router
show
Commands
Web
Server
SNMP
SNMP
AGENT
AGENT
HTTP/S
SNMP
MIBs
• MIB II
• RMON
• ART
• HCMON
• And more
TRAPS
telnet
CLI
Interfaces
Layer N Forwarding
Understanding the Basics
Let’s now look inside an intelligent switch or router. Many network-based devices have built-in intelligence to
assist in management activities. As traffic traverses the device interfaces, information about the amount and
type of traffic seen is stored in various operating system data structures, consisting of counters, gauges,
tables, timers, and files. The retrieval and/or modification of this information can be achieved through
numerous communication protocols (depending on the device type) including the traditional Command-Line
Interface (CLI), telnet, HTTP, Syslog, and TFTP.
In an effort to standardize the mechanism used for device status information necessary for network
management tasks, the Management Information Base (MIB) information model was created. The
information stored in these data structures is stored in standardized MIBs. The content within the MIBs are
well documented and easy to access using the MIB object identifier.
Likewise the Simple Network Management Protocol (SNMP) was chosen as the standardized
communication model for retrieving information held by the MIB, as well as alert IT managers to conditions
occurring within the managed device using SNMP traps.