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Network Management Security. CS 678 Network Security, Dept. of Computer Science, Long Island University,Brooklyn, NY. Outline. Basic Concepts of SNMP SNMPv1 Community Facility SNMPv3 Recommended Reading and WEB Sites. Basic Concepts of SNMP.
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Network Management Security CS 678 Network Security, Dept. of Computer Science, Long Island University,Brooklyn, NY CS 678 P. T. Chung
Outline • Basic Concepts of SNMP • SNMPv1 Community Facility • SNMPv3 • Recommended Reading and WEB Sites CS 678 P. T. Chung
Basic Concepts of SNMP • An integrated collection of tools for network monitoring and control. • Single operator interface • Minimal amount of separate equipment. Software and network communications capability built into the existing equipment • SNMP key elements: • Management station • Managament agent • Management information base • Network Management protocol • Get, Set and Notify CS 678 P. T. Chung
PRINCIPLE OPERATION CS 678 P. T. Chung
SNMP STRUCTURE CS 678 P. T. Chung
Protocol context of SNMP CS 678 P. T. Chung
Proxy Configuration CS 678 P. T. Chung
SNMP v1 and v2 • Trap – an unsolicited message (reporting an alarm condition) • SNMPv1 is ”connectionless” since it utilizes UDP (rather than TCP) as the transport layer protocol. • SNMPv2 allows the use of TCP for ”reliable, connection-oriented” service. CS 678 P. T. Chung
SNMP PROTOCOL CS 678 P. T. Chung
OVERVIEW OF PDUs CS 678 P. T. Chung
TO REQUEST THE VALUE OF 1 OR MORE VARIABLES POSSIBLE ERRORS: • • noSuchName Object does not exist / Object is not a leaf • • tooBig Result does not fit in response PDU • • genErr All other causes CS 678 P. T. Chung
EXAMPLE MIB CS 678 P. T. Chung
GET EXAMPLES get(1.1.0) • response(1.1.0 => 130.89.16.2) • get(1.2.0) • response(error-status = noSuchName) • get(1.1) • response(error-status = noSuchName) • get(1.1.0; 1.2.2.0) • response(1.1.0 => 130.89.16.2; 1.2.2.0 => 123456) • get(1.3.1.3.5.1) • response(1.3.1.3.5.1 => 2) • get(1.3.1.1.5.1) • response(1.3.1.1.5.1 => 5) • get(1.3.1.1.5.1, 1.3.1.2.5.1, 1.3.1.3.5.1) • response(1.3.1.1.5.1 => 5, 1.3.1.2.5.1 => 1, 1.3.1.3.5.1 => 2) CS 678 P. T. Chung
MESSAGE & PDU STRUCTURE CS 678 P. T. Chung
Comparison of SNMPv1 and SNMPv2 CS 678 P. T. Chung
SNMPv1 Community Facility • SNMP Community – Relationship between an SNMP agent and SNMP managers. • Three aspect of agent control: • Authentication service • Access policy • Proxy service CS 678 P. T. Chung
SNMPv1 Administrative Concepts CS 678 P. T. Chung
SNMPv2 PROTOCOL OPERATIONS CS 678 P. T. Chung
GET-BULK • NEW COMMAND getBulk IN SNMPv2 • TO RETRIEVE A LARGE NUMBER OF VARBINDS • IMPROVES PERFORMANCE! CS 678 P. T. Chung
GETBULK PERFORMANCE CS 678 P. T. Chung
GET-BULK EXAMPLE • getBulk(max-repetitions = 4; 1.1) response(1.1.0 => 130.89.16.2 1.2.1.0 => printer-1 1.2.2.0 => 123456 1.3.1.1.2.1 => 2 ) CS 678 P. T. Chung
GET-BULK EXAMPLE • getBulk(max-repetitions = 3; 1.3.1.1; 1.3.1.2; 1.3.1.3) response(1.3.1.1.2.1 => 2; 1.3.1.2.2.1 => 1; 1.3.1.3.2.1 => 2 1.3.1.1.3.1 => 3; 1.3.1.2.3.1 => 1; 1.3.1.3.3.1 => 3 1.3.1.1.5.1 => 5; 1.3.1.2.5.1 => 1; 1.3.1.3.5.1 => 2 ) CS 678 P. T. Chung
SNMPv3 • SNMPv3 defines a security capability to be used in conjunction with SNMPv1 or v2 CS 678 P. T. Chung
SNMP v3 DESIGN DECISIONS • ADDRESS THE NEED FOR SECURY SET SUPPORT • DEFINE AN ARCHITECTURE THAT ALLOWS FOR LONGEVITY OF SNMP • ALLOW THAT DIFFERENT PORTIONS OF THE ARCHITECTURE • MOVE AT DIFFERENT SPEEDS TOWARDS STANDARD STATUS CS 678 P. T. Chung
SNMP v3 DESIGN DECISIONS • ALLOW FOR FUTURE EXTENSIONS • KEEP SNMP AS SIMPLE AS POSSIBLE • ALLOW FOR MINIMAL IMPLEMENTATIONS • SUPPORT ALSO THE MORE COMPLEX FEATURES, • WHICH ARE REQUIRED IN LARGE NETWORKS • RE-USE EXISTING SPECIFICATIONS, WHENEVER POSSIBLE CS 678 P. T. Chung
SNMPv3 Flow CS 678 P. T. Chung
SNMPv3 ARCHITECTURE CS 678 P. T. Chung
Traditional SNMP Manager CS 678 P. T. Chung
Traditional SNMP Agent CS 678 P. T. Chung
SNMPv3 MESSAGE STRUCTURE CS 678 P. T. Chung
SNMP3 Message Format with USM CS 678 P. T. Chung
User Security Model (USM) • Designed to secure against: • Modification of information • Masquerade • Message stream modification • Disclosure • Not intended to secure against: • Denial of Service (DoS attack) • Traffic analysis CS 678 P. T. Chung
Key Localization Process CS 678 P. T. Chung
View-Based Access Control Model (VACM) • VACM has two characteristics: • Determines wheter access to a managed object should be allowed. • Make use of an MIB that: • Defines the access control policy for this agent. • Makes it possible for remote configuration to be used. CS 678 P. T. Chung
Access control decision CS 678 P. T. Chung
SECURE COMMUNICATION VERSUS ACCESS CONTROL CS 678 P. T. Chung
USM: SECURITY THREATS CS 678 P. T. Chung
USM MESSAGE STRUCTURE CS 678 P. T. Chung
IDEA BEHIND REPLAY PROTECTION CS 678 P. T. Chung
IDEA BEHIND DATA INTEGRITY AND AUTHENTICATION CS 678 P. T. Chung
IDEA BEHIND AUTHENTICATION CS 678 P. T. Chung
IDEA BEHIND THE DATA CONFIDENTIALITY (DES) CS 678 P. T. Chung
IDEA BEHIND ENCRYPTION CS 678 P. T. Chung
VIEW BASED ACCESS CONTROL MODEL • ACCESS CONTROL TABLE • MIB VIEWS CS 678 P. T. Chung
ACCESS CONTROL TABLES CS 678 P. T. Chung
MIB VIEWS CS 678 P. T. Chung
SNMPv3 RFCs CS 678 P. T. Chung
Recommended Reading and WEB Sites • Subramanian, Mani. Network Management. Addison-Wesley, 2000 • Stallings, W. SNMP, SNMPv1, SNMPv3 and RMON 1 and 2. Addison-Wesley, 1999 • IETF SNMPv3 working group (Web sites) • SNMPv3 Web sites CS 678 P. T. Chung