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Architecture
1.2
Five major energy supply domains
1.3
Four parts of the network management system
Manager, agent, network protocol, mib
NME network management entity
Centralized distributed distinction
centralized management station a plurality of managed objects
distributed management of a plurality of co-station managed objects, wherein the managed domain
agency
When there are non-standard equipment to be managed, an agent is required
1.4
Communication between management station and agent (polling: request and response, event report: trap)
1.5
Network monitoring
Two calculations (emphasis):
availability
Utilization rate: failure-free time/total time
series and parallel, probability
calculation steps are Three times, calculate the probability of two at the first time, and calculate the probability of one at the
second time. The second time the peak and non-peak availability are calculated. The
third weighted
response time is
divided into going and returning.
Utilization (load, capacity, relative load, relative utilization) is
a simple eg: Link 1: Relative load: 30/200, capacity 40/400, utilization rate 0.15/0.1=1.5
1.6
Browse
** Identify what is that functional domain
Two important points, but no small points, no doubts.
2.2
BNF (interger page 89) is legally selected
One and two are correct, one is a number, a positive number, and the other is an identifier. There is no such
ColorType capitalization type definition of identifier (integer)
Other BNF does not look
coloerA lowercase, value definition
Master ASN.1
Pay attention to case
Name case
Type definition
Value definition (no memory space allocated)
Label definition:
2.1 Table five types
set no need to watch
Tag category: universal, application, context-specific, private
Data type: simple (INTEGER, OCTET STRING is left unchecked), structured, tagged, ohter
eg: abc is the son of 13614, number 88
hardware is the son of abc, number For the first
question, you can try to give information and then make a tree diagram. The
five types are that sequence is a structural type.
Learn to define
the difference between a sequence type and a sequence of. For
other types, look at the choice, there is no label. Then confirm the assignment to confirm the tag. The
above is just a type reference, and the tags and tags of the previous type are used.
The
original type of the label type has a new label.
Implicit and explicit 
. Subtype: value range, can be recognized when you see it
2.3
Master all BER coding
Five general types + 5/6 types of snmp applications
Tag only remembers the short format
00000001 00000000 is 256
1 is fixed, which means there will be more later. 10000010 means the following 10 means there are two more bytes
length
Value is
because boolean is universal 01, so t is 01 and
depends on null, the positive and negative of the integer,
oid short and long format,
oid type
1*40+3=43/16=2B (combined only the first two digits),
long format:
seven One group and then make up eight digits. The
last octet one is 0
sequence, 30->00 1 10000 (16),
pay attention to the specific type and label
Implicit and explicit
Note here, even if it is a simple type, the PC bit here is 1. The explicit internal is an integer 02 (00 0 00002) L Note that it is 03
2.4
Module definition
EXPORTS FROM can be exported
IMPORTS FROM can be imported
Remember this DEFINITIONS
Macro Definition
Chapter 3
The community name is registered in the agent. The
get community name is wrong
. A trap will be sent, but it is not a response. It has nothing to do with get.
Four RFC
SMI
MIBs (the first five general types and five application types)
define management objects.
There are four managed objects. Elements
Object identifier (text name, OID), grammar, access, status, description (V2)
A managed object corresponds to a unique object type.
1212 adds many options to 1155. Improvements.
Managed objects are all leaf node
aggregation objects: table objects , Row objects (not leaves, no management information, tables should correspond to rows, rows correspond to columns. Also correspond to management objects),
non-aggregated objects: scalar objects, column objects (managed objects),
so distinguish between management objects and Tube object.
Scalar objects are leaf nodes.
Column objects are also leaf nodes. There are multiple instances.
Row object attributes are
column objects. The definition of the first column object
There is only one scalar object, so .0 at the end means an instance.
General rule:
fill in the last digit.
Special rule:
First determine that it is a variable-length string with special rules,
and then find the index column xyz to
find the abc identifier 1.3.6.1.2.1.2.2.2.1.2
Example 22 is written as follows.
Object identifiers do not know that you can write column names.
Indexes can be written as host
. Four characters, write 4 in the middle
1.3.6.1.2.1.2.2.2.1.2.4.104.111.115.116
that is, the
abc.4.host
network address, add 1 in the middle to indicate that it is an IP address
NetworkAddress type because it is a multiple choice question, The option has only one IpAddress,
so 1 is not the number of bytes written in it,
and the index of NetworkAddress is an ip, 
so OID.1.ip
itself is an OID type, and a few value
column objects must be added in between. Because there are multiple instances, so Index is needed. The
order of
the
dictionary is to be filled when the hole is dug . The order of the dictionary is getnext. The
mib-2
system group knows all.
For sysServices, it is necessary to count
which level of the device 76 = 64+8+4 application layer, transport layer, network layer
interface group You can see that the scalar object and the table object are brothers. The
interface group must master ifnumber
The child of the table object is the row object (emphasis)
The child of the row object is the column object
A look at the template of Experiment 1 is the key to understanding the importance of those groups
4.2 (Key points)
The trap is sent by the agent to the management station, and it is one-way.
As shown in the figure, the PDUs are all label types, and the trap is [4]
five types of PDU (ASN.1, BER must be mastered)
version number -1,
0 is v1
1 is
the
general PDU before the v2 community name : request identification, error status, error index, variable binding table.
Error status
getrequset/set is relatively simple.
getnext returns the next OID and value
L is a byte, 38 bytes.
Note that the PDU is all It is the SEQUENCE type.
If it is 2b 06 01 02 01 01 14, it is not 1.3.6.1.2.1.1.14, 14 is 20 to write 20
TrapPDU: manufacturer, proxy address, general trap type, special trap type, time stamp, variable binding The
first six types of the table are general traps, and the value 6 requires special traps.
161 for general PDU, 162 for trap
The son of the leaf node is his instance
4.7 (Key points)
inform (between management stations)
can be mixed without V1V2
In V2, the error may appear in the variable binding table, the error state, index 0 also depends on the variable binding table, there may be nosuchname and the
last one is the manufacturer ID: remember that it is not the system manufacturer, but the trap maker
Calculation
Error status (get)
4.5
Polling frequency
0.202 is 50ms 4+1ms 2=0.202s
4 50+2 500=1.2s
4.6
2578 Improve SMI for 1212
4.8V3
soctPDU
Chapter 5 The
difference between data table and control table
Utilization rate is the actual transmission bit number/theoretical
denominator bandwidth speed
Molecular formula packet overhead (64 preamble, 96 frame interval) + number of bytes*8
Draw stars (warning group).
This 123 is only at the beginning. The
remaining alarms have nothing to do with 123.
Chapter 6
Experiment 1
Write command (back system)
table operation
Chapter 7
Network management tasks 13
Chapter 8 Experiment 4
.
