Hcip first day notes

HCIA---- Huawei junior network engineer certification

HCIP---- Senior Network Engineer under Huawei certification system

HCIE---- Expert network engineer under Huawei certification system

Abstract language --- code

code --- Binary system

Binary system --- Electrical signals

Process electrical signals

agreement , standard , application , service

1、OSI Seven layer reference model （ Open Systems Interconnection Joint Reference Model ）

formula ： Should watch can transmit network data

application layer ： Provide various application services . You can convert abstract languages into code .

The presentation layer ： Convert the encoding to binary .

The session layer ： Maintain the session connection between the network application and the network server .

Transport layer ： Realize end-to-end transmission 、 Application to application transfer .

Port number （ The address of the transport layer ）： Distinguish and calibrate different applications , It's usually used 16 Bit binary structure （1-65535）

The network layer ： Realize logical addressing between hosts .

Get the target IP Address method ：
1、 Directly know each other's IP Address
2、 Access through domain name IP Address （DNS- Domain name resolution ）
3、 Direct access through the application
4、 radio broadcast – scanning
Data link layer ： Control physical hardware , Convert binary to electrical signal .

The network layer ： Realize logical addressing between hosts .

2、TCP/IP Model

TCP/IP Four layer model — TCP/IP The standard model

TCP/IP Five layer model — TCP/IP peer model

PDU--- Protocol data unit

3、PDU — Protocol data unit

L1PDU

L2PDU

..

7PDU

4、 Data type corresponding to each layer

application layer --- The data packet

Transport layer --- Data segment

The network layer --- Data packets

Data link layer --- Data frame

The physical layer --- Bit stream

5、 Encapsulation and de encapsulation

Encapsulation and de encapsulation

application layer --- There is encapsulation in the application layer , Depending on the application

Transport layer --- Port number ---TCP,UDP

The network layer ---IP Address ----IP

Data link layer ---MAC Address --- Ethernet protocol

The physical layer

 TCP/IP Models and OSI The difference between models ：TCP/IP The model supports cross layer encapsulation
TCP/IP The cross layer packaging of is generally used in the short-range communication between directly connected devices .
There are two main forms of cross layer packaging ：
1. Cross four layer packaging - - Routers are connected to each other - - OSPF - - Agreement No 89
8 Bit agreement , Assist in packaging across four layers , The third floor is for slicing .
2. Span three , Four layer package — Between directly connected switches —STP.
 

  MTU— Maximum transmission unit 1500
SOF— Frame header delimiter
DSAP- - A byte - - Indicates the upper layer protocol type of data frame reception
SSAP- - A byte - - Indicates the upper layer protocol type of the data frame transmission source
Control- - Two modes , One is connectionless , One is to establish reliable LLC conversation . It can complete the slicing operation .

6、IP Address — IP agreement （ Internet Protocol ）

IPV4 — 32 Bit binary structure — dotted decimal
IPV6 — 128 Bit binary structure — It's hexadecimal

7、IP Classification of addresses
A,B,C — Unicast address — It can be used as a source IP It can also be a goal IP Use
D — Multicast address — Only as a target IP Use , Cannot be used as a source IP Use .
E — Reserved address
A： Benchmarking large networks 255.0.0.0
B： Benchmarking medium-sized networks 255.255.0.0
C： Benchmarking small networks 255.255.255.0
stay IP In the address space , Some addresses are called private networks IP Address , The rest is called the public network IP Address .
A：10.0.0.0 - 10.255.255.255 — Equivalent to one A Class segment
B：172.16.0.0 - 172.31.255.255 ---- amount to 16 paragraph B Class segment
C：192.168.0.0 - 192.168.255.255 ---- amount to 256 individual C Class segment
We will generally use private networks IP The network of address communication is called private network , Will use the public network IP The address communication network uses the public network .

8、VLSM — Variable length subnet mask
192.168.1.0/24
192.168.1.0 0000000 --192.168.1.0/25
192.168.1.1 0000000—192.168.1.128/25

9、CIDR — No inter domain routing
Take the same , Go different ----- For binary

10、 route
The router will generate the routing information of the direct network segment by default
1, Dual interface UP;
2, The interface must be equipped with IP Address .
Get unknown route information of network segment ：
Static routing ： Routing entries manually configured by the network administrator
Dynamic routing ： Open the same routing protocol on all routers , after , Communicate through routers , negotiation , The final calculation generates routing entries .
Advantages of static routing ：
1, Will not take up additional resources
2, Because the routing administrator decided , therefore , Relatively more reasonable
3, More secure
Disadvantages of static routing ：
1, In a complex network environment , Large amount of configuration ;
2, Static routing cannot automatically converge based on the change of topology . ---- Static routing only
Used in small and simple network environment .
Basic configuration of static routing ：
Method 1 ：[r1]ip route-static 192.168.3.0 24 192.168.2.2 — direct
Write down the next jump — You need to find the interface recursively .
Method 2 ：
[r1]ip route-static 192.168.3.0 24 GigabitEthernet
0/0/1 ---- Just write the interface ---- You need to activate the router's proxy ARP function
[r2-GigabitEthernet0/0/0]arp-proxy enable — Activate the interface proxy
Method 3 ：[r1]ip route-static 192.168.3.0 24 GigabitEthernet 0/0/1
192.168.2.2 — Write the next jump and exit interface directly .
Method four ：[r1]ip route-static 192.168.4.0 24 192.168.3.2 — Just write down two jumps , But you need to find recursively , The recursive route must be written in advance
Static routing extension configuration
1. Load configuration
2. Manual configuration
3. Routing black holes
4. Default route
5. Empty interface routing
6. Floating static routing

 

 

​​​​​​​