PPP PointtoPoint Protocol Prof Choong Seon HONG Kyung

PPP (Point-to-Point Protocol) Prof. Choong Seon HONG Kyung Hee University 1

15. 1 천이상태(Transition State) q. PPP 연결이 이루어지는 단계 Kyung Hee University 3

15. 3 링크 제어 프로토콜(계속) q. LCP 패킷 필드 v코드(code) : LCP 패킷 종류 v. ID : used to match a request with the reply v길이 : LCP 패킷 전체 길이 v정보 : LCP 패킷에 필요한 정보 Kyung Hee University 9

15. 3 링크 제어 프로토콜(계속) q. LCP패킷 Code Packet Type Description 0116 Configure-request Contains the list of proposed options and their values 0216 Configure-ack Accepts all options proposed 0316 Configure-nak Announces that some options are not acceptable 0416 Configure-reject Announces that some options are not recognized 0516 Terminate-request Requests to shut the line down 0616 Terminate-ack Accepts the shut-down request 0716 Code-reject Announces an unknown code 0816 Protocol-reject Announces an unknown protocol 0916 Echo-request A type of hello message to check if the other end is alive. 0 A 16 Echo-reply The response to the echo-request message 0 B 16 Discard-request A request to discard the packet Kyung Hee University 10

15. 3 링크 제어 프로토콜(계속) q구성 패킷 v양 단말간 선택사항 협상 l Configure-request l Configure-ack l Configure-nak l Configure-reject Kyung Hee University 11

15. 3 링크 제어 프로토콜(계속) q 링크 종료 패킷 v. Terminate-request v. Terminate-ack q 링크 감시와 디버깅 패킷 v. Code-reject v. Protocol-reject v. Echo-request v. Echo-reply v. Discard-request Kyung Hee University 12

15. 3 링크 제어 프로토콜(계속) q선택사항 v두 단말간에 이루어지는 협상 Option Default Maximum receive unit 1500 Authentication protocol None Protocol field compression Off Address and control field compression Off Kyung Hee University 13

15. 4 인증 (Authentication) q자원 접근을 원하는 사용자 신원 증명 v PPP is designed for use over dial-up links where verification of user identity is necessary. v Authentication means validating the identity of a user who needs to access a set of resources q. PAP : Password Authentication Protocol q. CHAP : Challenge Handshake Authentication Protocol Kyung Hee University 14

15. 4 인증(계속) q. PAP 패킷 v. PPP 프레임에 캡슐화 Kyung Hee University 16

15. 4 인증(계속) q. CHAP(Challenge Handshake Authentication Protocol) v 3 way handshake 인증 프로토콜 v Password is never sent on-line Kyung Hee University 17

15. 4 인증(계속) q. CHAP 패킷 v. PPP 프레임에 캡슐화 Kyung Hee University 18

15. 5 네트워크 제어 프로토콜(계속) q. IPCP 패킷의 코드 값 Code Kyung Hee University IPCP packet 01 Configure-request 02 Configure-ack 03 Configure-nak 04 Configure-reject 05 Terminate-request 06 Terminate-ack 07 Code-reject 21

15. 6 예 Kyung Hee University 22