Linux Network Setup (second edition)--Internet addressing process

LinuxNetwork Settings--Internet addressing process

1.Comparison ofTCP/IP and OSI Reference Models

	Tcp / ip	Osi
Physical Layer	Card
Data Link Layer	*	MAC Address
Network layer	IP,ICMP,ARP Protocol
Transport Layer	Tcp,udp
Session Layer	*	Client – server
Presentation Layer	*	Data encryption, compression
Application Layer	SSH,Apache and other practical applications

2. Internet addressing process

1) MAC address

DC:0E:A1:D5:8A:B2 "Hardware address:6 section, three- input Writing"

Vendor identification ( front ): Network card identification ( rear )

Attached-Linux view:ifconfig eth0

Windows View:ipconfig/all

2)IP address

192.168.14.127 "IPv4: Three-position,4 - paragraph,ten - in writing"

"IPv6: The five-bit, write- in"

Expand-dos "Denial of service attack" Synflood ( like flooding request package , Yahoo is stopped , IPv6 to the issue of security strengthened )

3) TCP/UDP

TCP: Reliable, three-time handshake (breakpoint Reset, timer) "Two military issues" "point to points " full duplex

UDP: Fast, such as: QQ, audio / video sharing

4) fqhn- full computer name [ domain name ]

www.sdust.cn.

Host name "www". level two domain " Sdust " . Top-level domain " . CN " . root Domain " . "

Domain Hierarchy Service Structure

"The World has a group root domain Server"

4) ARP Address Resolution Protocol

ARP Parsing Process

Arp-a# viewing the ARP Cache table

arp-d [IP address ]# Delete ARP record

Arp-s [IP address ] [MAC address ]#添加ARP static record "added with caution , permanent effect "

5)RARP Reverse Address Resolution Protocol # know your MAC address and ask for your IP Address

Attached-if a host goes to access the WebServerof the B - host Port ,A The port of the host should be a Randomly allocated high port above

6) Domain name resolution becomes IP address

A)Hosts parsing mode "earliest":/etc/hosts file Save " also has save under Windows system"

Format:IP Address host name / domain name alias

This file has been used so far, such as some anti-virus software will be the IP address of an illegal website to 127.0.0.1 This native address

b)nis–network information System"Sun Company Development"

#文件的集中管理

C)dns–domain name System#domain domain name, realm

#整个互联网都是基于DNS Domain name resolution, where BIND is the most popular domain name resolution software

Delegated Management of domains

recursive query [ speed not fast ]

Client ----> www.csdn.net

1. Native DNS Server "cache (generalized cache)"

Therefore: if access to a Web site is slow, (1) may be insufficient bandwidth of optical cable, (2)theDNS Server does not have the site cache, need to first recursive parsing, ( 3 ) Poor server performance

2, root domain .

→.net

3.top-level domain . Net

→csdn.net

→ Return to DNS server

→ Return to Client

Caching mechanism

Generalized caching: If www.csdn.netis already located, the root domain will not be queried againthe next time youaccess www.263.net . ", instead of directly locating the . NET server If this is the re-access java.263.net , it was directly anchored to the 263.net server instead of accessing it again . NET Server

Attached:1, a MAC address can correspond to multiple IP addresses

Ifconfig eth0:1 192.168.1.1# Add a new virtual NIC eth0:1

2. One IP address can correspond to multiple MAC addresses

such as:cluster cluster technology for round-robin load, the average load due to different MAC address

Two NICs can be tied to an IPon Linuxfor acceleration

3, a domain name can correspond to multiple IP addresses

Under Windows : nslookup domain # You can view the IP addresses that are owned by the site

4, one IP can correspond to multiple domain names

Linux Network Setup (second edition)--Internet addressing process