SNMP Introduction

SNMP VEQSIONS 
VEQSION 1 
VEQSION 2 
VEQSION 3 
SNMP VI - The Least Secure version of 
SNMP Protocol due to its lack of encryption. sending 
passwords over Plain Text 
SNMP v2 - Large improvements in over the first version, 
including transport mappings, MIB Structure elements 
and most importantly, improved authentication and 
security updates. 
SNMP v3 - Implemented "User-Based 
Security". This security feature allows you to 
set Authentication/Encryption based on the 
user requirements. The 3 levels of auth. 
are: NoAuthNoPriv, AuthNoPriv and Authpriv.

 

Basic command of SNMP:

 

      • GET: The GET operation is a request sent by the manager to the managed device. It is performed to retrieve one or more values from the managed device.
      • GET NEXT: This operation is similar to the GET. The significant difference is that the GET NEXT operation retrieves the value of the next OID in the MIB tree.
      • GET BULK: The GETBULK operation is used to retrieve voluminous data from large MIB table.
      • SET: This operation is used by the managers to modify or assign the value of the Managed device.
      • TRAPS: Unlike the above commands which are initiated from the SNMP Manager, TRAPS are initiated by the Agents. It is a signal to the SNMP Manager by the Agent on the occurrence of an event.
      • INFORM: This command is similar to the TRAP initiated by the Agent, additionally INFORM includes confirmation from the SNMP manager on receiving the message.
      • RESPONSE: It is the command used to carry back the value(s) or signal of actions directed by the SNMP Manager.

 

 

cclTT(01 
DIRECTORY (1) 
wa.2(1) 
SYSTEM 
MIB Tree Diagram 
MIB 
The Registered Tree 
Root 
MEMBER BODY 
AUTHORITY 
AUSTRALIA 
EXPERIMENTAL 
PRIVATE 
JOINT Iso.cclTr12? 
ORGANIZATION (3) 
DOD 
INTERNET 
SNMP

 

 

 

OID:

This is a sample structure of OD:

Iso(1).org(3).dod(6).internet(1).private(4).transition(868).products(2).chassis(4).card(1).slotCps(2)-cpsSlotSummary(1).cpsModuleTable(1).cpsModuleEntry(1).cpsModuleModel(3).3562.3

 

or just:

1.3.6.1.4.868.2.4.1.2.1.1.1.3.3562.3

 

Private OID:

Many manufactures can supply custom MIB files for their hardware ,such as temperature , fan speed.

The MIB file is hard to read, they are only meant to be imported, or "compiled " by a Management Station.

Below is an example of Cisco MIB file for environment monitoring.

计算机生成了可选文字:
S 2 iOOCISCOEnVMonVO ItagestatusEntry 
0 日 ] ECT —TY P E 囗 
SYNTAX 
M × 一 C 匚 E 5 5 not—accessibleO 
STAT 凵 5 
C 凵 r r e nt 囗 
凵 苁 n entry n the voltage S t at 凵 S 
D E 5 匚 R I PT 10 N 囗 
t 彐 匕 ] e , representing the S t at 凵 S 囗 
Of the associated 
testpoint maintained 匕 the environmentalO 
{ CiSCOEnVMonV01tageStatuSIndex } 囗 
m 囗 n ] t 囗 r 。 
I N D EX 
{ CiSCOEnVMonV01tageStatuSTab1e 1 } 囗 囗 
SEQUENCE { 囗 
Integer32 ( 0 . . 214 74 8 54 7 〕 , 囗 
Displ aystring , 囗 
dl_OW I e g e r 2 , 囗 
ciscoEnVMonVOltageThresholdHigh I nt e g e r 2 , 
CiSCOEnVMonV01tageLaStShutdown I e g e r 2 , 囗 
CiSCOEnVMonV01tageState 
匚 ] S C 囗 E 囗 n St 
CiSCOEnVMonV01tageStatuSIndex 0 日 ] ECT —TY P E 囗 
SYNTAX 
Integer32 ( 0 . . 21474H 547 〕 囗 
STAT 凵 5 
C 凵 r r e nt 囗 
M × 一 C 匚 E 5 5 not—accessibleO 
D E 5 匚 R I PT 10 N 囗 
index for the testpoint being 
This index S for 5 NM P purposes 囗 n ] , and has n 囗 囗 
] nt r ] n S ] C m e 彐 n ] n 0 。 凵 囗

 

Cisco MIB information:

http://snmp.cloudapps.cisco.com/Support/SNMP/do/BrowseMIB.do?local=en&step=2

 

Load MIB file:

The files below is F5 MIB file.

计算机生成了可选文字:
F5 一 8 《 G 《 P . 监 PM 一 M 《 8 
F5-BIGIP-COMMON-MIB 
F5 . 8 《 G 《 P . GLOB 监 L . M 化 
F5-81GIP-LOCAL-M18 
F5-81GIP-SYSTEM-M18 
2012 / 3 / 28 星 期 
2012 / 3 / 28 星 期 
2012 / 3 / 28 星 期 
2012 / 3 / 28 星 期 . 
2012 / 3 / 28 星 期 
交 本 交 栏 
交 本 交 栏 
交 本 交 栏 
交 本 交 栏 
交 本 交 栏 
105 KB 
30 KB 
1g5 KB 
5 31 KB 
401 KB

 

We can use MIB Browser to load these file ,and you can see the F5 private OID in the picture.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



posted @ 2016-10-27 13:24  rong-shao  阅读(...)  评论(...编辑  收藏