Shulou(Shulou.com)06/03 Report--

Network foundation

IPv4 network

TCP4 layer

IP address: V4 version: 32 binary numbers, each 8-bit group, representing the identity of each computer in the network

192.168.1.1 192.168.2.1

Divided into network bits and host bits, the same network bits, different host bits can communicate

Five kinds of networks are defined according to the environment in which IP is used.

Divided into public IP and private IP

Special IP:169 start-automatic private IP address (IP address conflict and unable to obtain IP address)

127.0.0.1-Local Loopback-Localhost

Subnet mask: 32 binary digits, a set of 8 bits, consisting of consecutive identical 01s from left to right

192.168.1.100/30 192.168.1.1/24

255.255.255.252 255.255.255.0

11000000.10101000.00000001.01100100

11111111.11111111.11111111.11111100

11000000.10101000.00000001.01100100

192.168.1.100

11000000.10101000.00000001.00000001

11111111.11111111.11111111.00000000

11000000.10101000.00000001.00000000

192.168.1.0

The network segment to which the IP belongs is defined through the result of the "and" operation of the subnet and IP, and the IP of the same network segment can communicate.

You can define subnets to help configure IP addresses to achieve more networks & host = subnetting

Display mode: 255.255.255.0hammer 24

Gateway (GW)

When the IP addresses of two different networks need to communicate

You can use a device with IP address forwarding (router & switch) that is configured to match the desired IP address of the currently connected network

On computers on different networks, add the IP that can forward the IP address device to the "gateway" information of the local computer that matches the IP address network of the current computer.

When the local computer sends data to different networks, it first sends the data to the IP address in the Gateway information

DNS: domain name resolution

The client first submits the domain name that needs to be resolved by the DNS server, and DNS returns the information of the domain name submitted by the client (IP address)

Order of client domain name resolution: local cache: ipconfig / displaydns

/ flushdns

Local Hosts file

The IP address of the DNS server in the Nic settings

Get-DnsClientServerAddress

Nslookup uses the IP address of the local computer's DNS to query the information in the DNS server.

Set type=A,TXT,MX record type

Set IP address: Get-NetIPAddress

Set-NetIPAddress

Common tools: ipconfig,ping,tracert,telnet (manual installation required)

Network information analysis tool Microsoft Message Analyzer (protocol, message)

IPv6:

Huge address pool: 2001:DB8:0:2D4C:1CC:DD:1122:1234 recommends allocation through DHCP

IPv6 security: requires end-to-end encryption

Typical IPv6 address: local private address starting with fe80 = 169A

:: 1x 127.0.0.1

Configuration: some important servers (DC, mail) disable the IPv6 protocol in a network environment without IPv6

Https://github.com/bannedbook/fanqiang/wiki

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