网络管理(Network Management)

Infrastructure for network management

Internet-standard management framework

SNMP overview: 4 key parts

Management information base (MIB):
- distributed information store of network management data
Structure of Management Information (SMI):
- data definition language for MIB objects
SNMP protocol
- convey manager<->managed object info, commands
security, administration capabilities
- major addition in SNMPv3

SMI: data definition language

Purpose: syntax, semantics of management data well-defined, unambiguous
base data types:
- straightforward, boring
OBJECT-TYPE
- data type, status, semantics of managed object
MODULE-IDENTITY
- groups related objects into MIB module

Basic Data Types:

INTEGER
Integer32
Unsigned32
OCTET STRING
OBJECT IDENTIFIED
IPaddress
Counter32
Counter64
Guage32
Time Ticks
Opaque

SNMP MIB:

SMI: object, module examples

OBJECT-TYPE: ipInDelivers

ipInDelivers OBJECT TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
     “The total number of input 
      datagrams successfully 
      delivered to IP user-
      protocols (including ICMP)”
      ::= { ip   9}

MODULE-IDENTITY: ipMIB

ipMIB MODULE-IDENTITY
  LAST-UPDATED “941101000Z”
  ORGANZATION “IETF SNPv2
             Working Group”
  CONTACT-INFO
     “ Keith McCloghrie
     ……”
  DESCRIPTION
     “The MIB module for managing IP
     and ICMP implementations, but
     excluding their management of
     IP routes.”
  REVISION “019331000Z”
 ………
::= {mib-2 48}

MIB example: UDP module

SNMP naming

question: how to name every possible standard object (protocol, data, more..) in every possible network standard??
answer: ISO Object Identifier tree:
- hierarchical naming of all objects
- each branchpoint has name, number