TCP/IP plots

Basic knowledge of the network

ISO 7-layer model (P36)

Application layer:

Presentation layer:

Session Layer:

Transport Layer:

Network layer:

Data Link Layer:

Physical Layer:

Throughput and transfer speed: transfer speed between hosts, called throughput, unit bps

Repeater (physical layer): Connect two identical media

Hubs (P56): can also be seen as multiple repeaters

Self-learning Bridge (data Link layer): Ability to determine whether a message is sent to an adjacent network segment

3-tier Router

Layer 4-7 Switch

Packet Exchange: Divides the data into several ways to transmit it. which

Broadcasting:

Default route:

Loop routing

Full Duplex

Half Duplex

Network layer

Network identity

Host identification

Subnet mask

Network address

IP Address

1. Split processing and reorganization processing

2. Path MTU Discovery

IP protocol-related technologies (P179)

DNS (domain Name System)

Domain Name: http://www.jxust.cn/(Jiangxi Polytechnic University)

Domain Name server: The host of the management domain name, that is, each layer of the domain name server manages the following layer of the domain name server, for example, this tier server is the JP domain name, it manages the next layer of server domain name (co,ac domain name).

ARP Request (P181): A sending host sends an "IP address" via "broadcast" to the receiving host, gets the MAC address of the receiving host, caches the MAC address, but this address is subject to a certain period of time

ICMP (Transmission Control Message) (P185):

ICMP Redirect message: An ICMP Redirect message is returned to the host when a closer route is found.

ICMP Timeout message: Prevents the loop condition. (one field is the TTL, and each router that encounters it automatically decrements by 1, knowing that 0 will end.) ）

ICMP echo message: Used to determine whether the sent packet was successfully reached opposite. Send message to host side, receive end response reply

DHCP (P193): Free IP address assignment

NAT: Convert LAN IP address to global network IP address

6.1 Function of the Transport layer (P196)

TCP: Packet sequence control and packet loss control in order scrambling

UDP: High-speed transmission and real-time requirements

Socket: IP address to end (or host), port number

Same communication: Source address IP, Destination address IP, source port number, destination port number, protocol

Window control: (Do not understand) TCP flow control (flow control) (P229): The sender will be based on the receiving end of the instructions, the amount of data sent to control.

Congestion window: (not understood) (P231)

TCP/IP plots