[HCIA continuous update] WAN technology

WAN technology

WAN technology PPP

Overview of early WAN technology

1、 LAN is a kind of network that covers a relatively large area

2、 Wan is a way of renting ISP Network or self built private network to build a computer network covering a wide geographical area

Introduction to the role of Wan equipment

There are three kinds of basic Wan devices ,CE( User edge devices )、PE（ Service providers provide edge devices ） and P（ Service provider equipment ）

The specific definition is ：

CE:CE Connect one or more PE, Realize user access

PE:PE Simultaneous connection CE and P equipment , Is an important network node

P: The service provider does not connect to any CE The equipment

ppp Link establishment process

Link layer negotiation ： adopt LCP The message carries out link parameter negotiation , Establish link layer links

Authentication negotiation ： Negotiate the link parameters through the link establishment stage , Establish link layer links

Network layer negotiation ： adopt NCP Negotiation to select and configure a network layer protocol and negotiate network layer parameters

PPP Interface state machine

LCP Message format

PPP Authentication mode —— PAP

1、 After successful link negotiation , Conduct certification negotiation （ This process is optional ）. There are two modes of authentication negotiation ,PAP and CHAP

2、PAP Two handshakes between the certification parties . The negotiation content is disseminated in clear text

3、CHAP There are three handshakes between the certification parties . The negotiation message is encrypted before transmission on the link

NCP negotiation

static state IP Address negotiation

1、PPP After certification , Both sides enter NCP Negotiation stage , Negotiate the format and type of data packets transmitted on the data link . With the common IPCP For example, the protocol is divided into static IP Negotiation and dynamics IP negotiation

2、 static state IP Negotiation requires manual configuration at both ends of the link IIP Address

3、 dynamic IP Negotiation support PPP The first segment of the link is configured at the opposite end IP Address

PPP Authentication configuration command

1、 Configure the authentication method to PAP Mode authentication peer

local-user user-name password {cipher | irreversible-cipher} password
local-user user-name service-type ppp

ppp authentication-mode pap

2、 Configure the verified party to PAP The method is verified by the other party

ppp pap local-user user-name password {cipher | simple} password

WAN technology PPPoE

What is? PPPoE

PPPoE Basic configuration

1、 Configure origination through dial-up Planning PPPoE Conditions of conversation

dialer-rule

2、 Configure the dial-up interface user name , This user name must be the same as the opposite server user name

dialer user username

3、 Put the interface into a dial-up access group

dialer-group group-number

4、 Specify the dial-up binding used by the current dial-up interface

dialer-bundle number

5、 Connect the physical port with dialer-bundle Binding

pppoe-client dial-bundle-number number

The development of WAN technology

Segment Routing brief introduction

To solve the tradition ip Forwarding and MPLS Forwarding problems , The industry put forward SR.SR The forwarding mechanism of has been greatly improved , Mainly reflected in the following aspects

• Extend based on existing protocols
• Move in source routing mechanism
• The network is defined by the business