Computer network (Network Part II) 1–2 days

Second, the answer

Day 01

1. What is the role of IP address? IP address classification?
The role of an IP address: The network address used to identify a node.
IP Address Classification: class A 1-127
Class B 128-191
Class C 192-223

2. What is the subnet mask? Default A B class C subnet mask?

The role of the subnet mask: The network bit and the host bit used to identify the IP address.
Class A: 255.0.0.0
Class B: 255.255.0.0
Class C: 255.255.255.0

3. What is the role of the gateway?

The gateway's role: from one network to another.

4. What is the role of public and private addresses and the scope of private addresses?

Public Address: Public address can also be called a public address, through which he can directly access the Internet, he is in the WAN category
Of
The function of private address: Private address can also be called a special network address, specifically for the internal use of the organization, he is within the scope of the LAN,
Out of the local area network is unable to access the Internet.

Range of private addresses:
A: Class 10.0.0.1-10.255.255.254
B: Class 172.16.0.1-172.31.255.254
C: Class 192.168.0.1-192.168.255.254

5. How to view the Windows host IP address with a command, how to view the Windows host MAC address with a command?
Start-command prompt-run ipconfig

View IP in Linux: Run Ifconfig directly
View MAC Address: Start-command prompt-run ipconfig/all.

Day 02

1. What is the function of the computer network?
Function of network: Data communication resource sharing increases reliability and improves system processing ability

2. Conversion of computer storage units?
Computer storage can be measured in bits and bytes
8 Guests
1 bytes
1024 byte 1KB
1024KB 1MB
1024MB 1GB
1024GB 1TB
1024TB 1PB
1024PB 1EB

3. How many layers does the OSI reference Model have? name and function of each layer?
OSI Reference Model A total of seven layers from bottom to top are physical layers-data Link layer-network layer-Transport Layer-session Layer-presentation layer-should
Use layer

The meaning of each layer:
Physical layer: Establishes, maintains, disconnects the physical connection, defines the interface and the medium, realizes the transmission of the bit stream.
Data Link layer: the establishment of logical links, hardware address addressing, error checking and other functions, through the MAC address to achieve data communication,
Frame wrapping, frame transfer, frame synchronization. The switch works at the data link layer.
Network layer: Logical address addressing, the realization of communication between different networks, the definition of IP address, for data transmission selection of the best path
The router works at the network layer.
Transport Layer: Defines the protocol port number of the transmitted data, as well as the flow control and error checking, realizes the interconnection between program and program, reliable and not
Reliable transmission.
Session Layer: Establish, manage, abort sessions, such as breakpoint continuation.
Presentation layer: The representation of data, such as encryption, compression.
Application layer: An excuse for Web services and end users

4. Four-layer data unit under OSI Seven-layer Reference Model
Transport Layer Segment segment
Network Layer Pack Packet

Data Link Layer Frames frame
Physical layer bit bit

What are the layers of the 5.TCP/IP agreement? What's the name?
The TCP/IP protocol consists of five layers or four layers:
TCP/IP layer four
Network interface Layer
Network layer
Transport Layer
Application Layer
TCP/IP layer Five
Physical Layer
Data Link Layer
Network layer
Transport Layer
Application Layer

6. Application, transmission, Network layer protocol?
Application layer: Http,https,ftp,tftp,smtp,pop3,snmp,dns,telnet
Transport Layer: TCP,UDP
Network layer: Icmp,igmp,ip,arp,rarp

7. TCP/IP five layers per layer of equipment
Application-tier computers
Transport Layer Firewall
Network layer Routers
Data Link Layer Switches
Physical Layer NIC

Computer network (Network Part II) 1–2 days