Keeping Tabs on Your Network First, a Horror Story Types of Management Tools What is SNMP?...
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Transcript of Keeping Tabs on Your Network First, a Horror Story Types of Management Tools What is SNMP?...
Keeping Tabs on Your Network
First, a Horror Story
Types of Management Tools
What is SNMP?
Dartmouth’s Net Management
InterMapper demo
Questions
Rich Brown
Dartware, LLC
20 May 2005
A Horror Story
What happened…
How could it have been prevented?
What is Network Management?
A set of tools that:– Help you know what’s happening in your net– Help you administer your network– Make you look good with your customers...– By actually doing a good job
Network Management System
MonitoringSystem
Servers Servers
Routers &Routers & SwitchesSwitches
Wireless gearWireless gear
EnvironmentalEnvironmentalSensorsSensors
Power SystemsPower Systems
E-mail, PagersE-mail, Pagers & Sounds& Sounds
Web Pages/Web Pages/Remote ViewsRemote Views
Strip ChartsStrip Charts
Diagram of Diagram of the the networknetwork
Log FilesLog Files
Types of Management Tools
Fault Management Configuration Management Security Management Performance Management Accounting Management Asset Management Planning Management Content Management
What is SNMP?
SNMP is a protocol (set of rules) for conveying management or status information from devices such as servers, workstations, routers, switches, radios and other gear to a management station.
Two ways to get data from a device– Management station “pulls” data from a device
being tested (the SNMP Agent)– Agent “pushes” a trap to the management station
The data values are defined by a MIB
What’s a MIB?
“Management Information Base” MIB defines the kinds of data a device tracks MIBs for various devices
– Router or Switch: traffic (packet & byte counts) & error counts (receive, transmit, discards, etc)
– Web Server MIB shows pages served, 404s, 401s, etc.– Mail Server MIB shows messages processed, queue lengths– Environmental sensors: temperatures, switch closures,
water on floor, door alarm, others– Typical Radio MIB: RSL, BER, number of subscribers,
bandwidth, inside/outside temperature, etc.
What’s an OID?
“Object Identifier” The “name” of the variable Always starts with 1.3.6.1…
– 1.3.6.1.2.1… for standardized MIBs– 1.3.6.1.4.1… for vendor specific MIBs
Four Basic SNMP Operations
– Get Retrieves the value of a MIB variable stored on the agent
machine (gauge, counter, string, or address of another MIB variable)
– GetNext Retrieves the value of the “next” MIB variable
– Set Changes the value of a MIB variable
– Trap An unsolicited notification sent by an agent to a
management application (typically a notification of something unexpected, like an error)
Traps
Traps are unsolicited reports that are sent to a management system by an SNMP agent process
When an interesting event occurs, an agent generates a trap message and sends it to a designated network address
Many events can be configured to signal a trap, like a network cable fault, failing NNIC of hard drive, a general protection fault, or a power supply failure
Ports & UDP
SNMP uses User Datagram Protocol (UDP) as the transport mechanism for SNMP messages
Like FTP, SNMP uses two well-known ports to operate:– UDP Port 161 SNMP Get/Set Messages– UDP Port 162 SNMP Trap Messages
Advantages of using SNMP
Standardized Widely supported by many vendors Distributed management access Lightweight protocol
SNMP Management Solutions
Open Source – Nagios, Big Brother, MRTG, perl scripts
Commercial SMB – InterMapper, WhatsUp Gold, IPMonitor
Commercial Enterprise – OpenView, Tivoli, Unicenter, BMC Patrol
Dartmouth’s Net Management
A variety of tools...– InterMapper– Aruba wireless monitoring tools– Spam filtering – NAT for entire campus
InterMapper Demo
InterMapper is a fault management tool Monitors network equipment and servers
24x7 to alert the manager about troubles Some performance management tools Get a demo from
http://www.intermapper.com
Questions
Ask now, or e-mail me– [email protected]
Thanks!
Bonus Slides
These slides didn’t fit into the presentation, but we kept them for your information...
Why is it Important?
To give Good Service and be professional A management system helps you to:
– Know about problems before the phone rings– Know how your network’s configured—documentation– Know how your network is operating– Know about network limits before you hit the wall
You can start small– Fault and Performance Management are critical– Implement other tools as your network grows
Types of Network Management
Fault Management: Reactive and proactive network fault management
Performance Management: Number of packets dropped, timeouts, collisions, CRC errors, response times
Configuration Management: Inventory, configuration, provisioning
Planning Management: Analysis of trends to help justify a network upgrade or a bandwidth increase
Security Management: SNMP doesn't provide much here Accounting Management: Cost management and chargeback
assessment Asset Management: Statistics of equipment, facility and
administration personnel
Benefits of using SNMP
Vendor Neutral Tools for Monitoring Universal Support Monitor lots of interesting information
Client Pull & Server Push
SNMP is a client “pull” model– The management system (client) “pulls”
data from the agent (server) SNMP also provides “server push” model
– The agent (server) “pushes” out a trap message to a (client) management system
Fault Management
Discover that a problem exists Notify the responsible parties Isolate the problem; show what is working Possibly fix the problem
Configuration Management
Configure critical devices consistently– e.g. Routers and Servers
Take inventory of important software on workstations
Update computers automatically
Security Management
Controlling access to information on the network
Setting up accounts; testing passwords Firewalls & Intrusion Detection Systems
Performance Management
Collecting and analyzing data about use Setting thresholds for alarms Simulating alternatives to find maximum
performance Study trends and make predictions
Accounting Management
Tracking individual or group use of network resources
Billing for use Controlling use of network
Stand-alone vs. Platform
Stand-alone programs solve specific problems; can be well-targeted and inexpensive; usually are easy to set up; but often duplicate notification, logging, databases, etc.
Platforms provide base services plus plug-in modules; unified notifications, logging, databases; but can be very expensive to buy and hard to set up
Which ones do I need?
Everyone needs security management tools: at least a firewall and access control– This will become true at your home when you
get cable modem or DSL service Fault management tools give timely warnings For the other tools, it depends…