Simple Network Management Protocol SNMP Agents

1
Simple Network Management Protocol (SNMP) - Agents

• Jeramie Reese

2
Agenda

• SNMP Components
• Architecture
• Creating a SNMP Agent
• References

3
SNMP Components

• Three key components
• Management Information Base (MIB)
• SNMP Agent
• Network Management System (NMS)

4
SNMP Architecture
SNMP Architecture An SNMP message passes through
the protocol layers at both the manager and
agent. Each layer does a specific communication
task.4
5
Layered Communication
6
Creating a SNMP Agent

• Required Components
• MIB Definition File
• C header file
• C Implementation file
• Additional steps after template code is generated
• Implement GET and SET request functions

7
Management Information Base (MIB) file

• Object Identifier (OID) vs. Naming structure
• The first four numbers of the OBJECT IDENTIFIER
  are always 1.3.6.1, where
• 1 Intern. Stds Org (ISO)
• 3 Org. recognized by ISO
• 6 Dept. of Defense (DoD)
• 1 Internet community
• Internet Assigned Number Authority
  (http//www.iana.org)

The branch of the MIB object identifier tree.5
8
SNMP Development Tools

• Net-SNMP (previously known as UCD-SNMP)
• http//net-snmp.sourceforge.net/
• Perl/SNMP Module
• mib2c Generates template code for the agent
• C header file
• C implementation file
• Loriot

9
Lessons Learned

• Simple Network Management Protocol Simple?
• Utilize predefined MIB files
• Understand the limitations
• Security concerns
• Compatibility

10
Bibliography

• Blank-Edelman, N. David. Perl for System
  Administration. Cambridege OReilly, 2000. (2)
• Cisco Systems, Inc., Simple Network Management
  Protocol, 20 February 2002, lthttp//www.cisco.com
  /univercd/cc/td/doc/cisintwk/ito_doc/snmp.htmxtoc
  id1gt (22 November 2004). (3)
• Cohen, Yoram, SNMP - Simple Network Management
  Protocol, 01 April 1995, lt http//www2.rad.com/ne
  tworks/1995/snmp/snmp.htmgt (22 November 2004).
  (6)
• DenHartog, Marshall, SNMP Tutorial The Fast
  Track Introduction to SNMP Alarm Monitoring. DPS
  Telecom. 27 September 2004. (5)
• DPS Telecom, SNMP Tutorial Series 5 Quick Steps
  to Understanding SNMP and its Role in Network
  Alarm Monitoring, 13 February 2003,
  lthttp//www.dpstele.com/layers/l2/snmp_tutorials.h
  tmlgt (22 November 2004). (1)

11
Bibliography (cont.)

•  
• Kozierok, Charles M., The TCP/IP Guide, 20 June
  2004, lt http//www.tcpipguide.com/free/t_SNMPVersi
  on1SNMPv1MessageFormat.htmgt (22 November 2004).
• SkillSoft Press, Using SNMP to Manage Complex
  Networks, 03 May 2002, lthttp//www.books24x7.com/
  book/id_4502/toc.aspgt (22 November 2004).
• Steinke, Steve, Simple Network Management
  Protocol - SNMP The most widely adopted standard
  provides a way for devices and consoles to
  communicate, 01 February 1997,
  lthttp//www.networkmagazine.com/article/NMG2000072
  4S0050gt (22 November 2004).
• Window Security, Network Management Protocol
  Insecurity SNMPv1, 16 October 2002, lt
  http//www.secinf.net/misc/Network_Management_Prot
  ocol_Insecurity_SNMPv1_.htmlgt (22 November 2004).
• Lake, Craig. Simple Network Management Protocol
  (SNMP) online. Available WWW ltURL
  http//www.sei.cmu.edu/str/docs/SNMP.htmlgt
  (1996).