Package for synchronous serial link (serail point-to-point link)3.1-hdlc/ppp High-level Data link Control HDLC (high-level Data Link controls): is a bit-oriented synchronous data Link layer protocol developed by ISO, developed by the SDLC protocol. HDLC Specifies the encapsulation on a synchronous serial line by using frame characters and checksums, and HDLC is generally not recommended ;HDLC does not support multiprotocol Ip;cisco in order to enable it to support multiple protocols and add a private bit to its frame header format: Multi-protocol support Ip/ipx/at (AppleTalk) but no longer compatible with other brands;HDLC does not support authentication and therefore cannot guarantee network security;Cisco's devices default encapsulation HDLC. dot-to-Point Protocol PPP (point-to-point Protocol): PPP is the industry's open standards, supporting multi-protocol environment, compatible with all brands; Huawei's devices default package PPP;the predecessor of PPP is the Serial Line protocol slip (Serial lines Interface Protocol), which tends to be phased out due to the single function;  PPP is divided into two parts: Link Control Protocol LCP (link control protocol Responsible for the establishment, control and maintenance of the L1 physical layer; Network Control protocol NCP (network control protocol=IPCP+CDPCP " is responsible for L3 network layer down provides an undifferentiated interface (*CP "), so it can also be said that PPP is Two-layer semi-protocol which is a L3 protocol with some L2 functions; LCP contains 4 large network modules: authentication (authentication)/compression (Compress)/ callback (Callback)/ Multilink Bundle (mulit-link). PPP Certification: ∵PPP is the L2 protocol ∴PPP authentication is link authentication → Once the authentication is successful, the link is no longer authenticated before the link is down; there are two types of PPP authentication:PlainText Password Authentication pap (Password authentication Protocol): Two-time handshake (the authenticated party sends the account password → The main authentication party compares the account password and responds according to the result ); PAP's account password is spread on the internet, not safe. ;Ciphertext Password Authentication chap (Challenge Handshake Authentication Protocol): Three-time handshake ( The main authentication party sends garbled challenge→ both sides use the MD5 irreversible arithmetic operation and the authentication party sends the result → The main authentication party compares the result to respond according to the result ; chap's account password is not transmitted on the network, security is good, recommended use. PPP negotiation process: 1:interface Serial0, changed state-to-up (L1up); 2:lcp:state is Open;3:PPP Certification ( This is an optional project, if the certification, it must be successful, only the NCP work );4-1:se1 ipcp:state is Open (IP);4-2:se1 cdpcp:state is Open (CDP:show CDP neighbor);5:line protocol on interface serial1,changed state to Up (L2up). ----------------------------------------------------------------------------LAB1: Use HDLC to encapsulate point-to-point links: STEP1: Encapsulates HDLC between interfaces (default): build topology to confirm L1/l2/l3 Tongda (l1:v.35/l2:hdlc/l3:routed network protocol IP and Routing pathfinding protocol Rip); then view (sh in S 0): L1 is up,l2 are up ... Encapsulation HDLC;STEP2: Run RIP:----------------------------------------------------------------------------LAB2: Use PPP to encapsulate point-to-point links: STEP1: Encapsulates PPP between interfaces on a serial link: connected to a topology, the interface between the R1/R3: (c-i) #encapsulation ppp; You can open the debug post sh/no SH interface to view PPP negotiation:# debug ppp encapsulation:l1 State was UP→LCP State is op EN→IPCP State was OPEN→CDPCP state was Open→l2 state was up;re-View interface information (sh in S 0): L1 is up,l2 are up ... Encapsulation PPP,LCP is open OPEN:IPCP,CDPCP ... ;after the view, it is best to close debug:#no debug ppp encapsulation; STEP2: Ping each other between R3 and R1: It 's going to work! Why? How Routing Works ...32-bit host routes on the R1#PPP Link's interface: C 13.0.0.3/32; (c) #in S1→no peer Neighbor-route ( only valid for this r ). Route (Route V. verb): The core word forwarding forwarding, the process for the router to receive information from the interface after the L2 frame header frame (source address and destination address is the previous router to send this information frame and this information frame to receive this message router), and then view the L3 Layer header packet (source address and destination address is the origin of this packet router and To receive the final router for this packet), then query its own routing table to find the outbound interface to the destination address and the next router (Next hop), And according to the encapsulation between the two L2 frame head frame (the source address and destination address is the router that sends this information frame and the next router to receive this frame) and emit this frame from the outbound interface; package → unpack → package → unpack → package: hop count (Hops) thus affects the cost of routing. ----------------------------------------------------------------------------LAB3:PPP's Certification: STEP1: For PAP certification: First make sure that the R1/R3 link is already PPP encapsulated (SH in S 0): L1 is up,l2 are up ... Encapsulation PPP; then create an account/password for each other on both routers: (c) #use rname r3n password r3p and ... ;then on both sides of the interface selected authentication mode for PAP: (c-i) #Ppp authentication pap;finally enter the account/password on both interfaces: (c-i) #ppp pap sent-username r1n password r1p and ... ;You can open the debug post sh/no SH interface to view PPP negotiation: #Debug ppp encapsulation;The mutual ping between R3 and R1 can pass, why; STEP2: For CHAP authentication: this time on the R1/R2, first make sure that the link between the links is already PPP package, not on the change (c-i#en p);then the same is on both sides of the router to establish an account/password for each other : (c) # use Rname R2 password r1r2p and ... Special note: The passwords of both sides must be consistent Oh, otherwise the results of the MD5 operation must be different, there are accounts to use the other side of the router name , you can try separately;then on both sides of the interface selected authentication Mode PPP: (c-i) #Ppp authentication cHap;if the name is different:: (c-i) #Ppp authentication chap→ppp chap hostname r2→ppp cHap password r1r2p good trouble ...You can open the debug post sh/no SH interface to view PPP negotiation: #Debug ppp encapsulation. ----------------------------------------------------------------------------LAB4:PPP MLP (multilink Protocol): STEP1: Building a topology:The original configuration of the redundant link interface is removed; it needs to be at both ends of the DCE-→R2 clock. The MLP is L2 redundant, comparing the L3 redundancy of RIP: L3 The convergence rate of redundancy is usually slower than that of the routing protocol;before the experiment with #sh controllers serial view:HD Unit 0, IDB = 0x939294, driver structure at 0x940860......buffer size 1524 HD Unit 0, v.35 DCE cable, Clockrate 64 000......CPB = 0xe1, EDA = 0x5078, CDA = 0x508c ... RX ring with + entries at 0xe15000; STEP2: The interfaces on both ends of the link encapsulate PPP and run MLP: (c) #in S0→en PPP→PPP multilink; STEP3: Create a virtual template interface on both routers: (c) #Interface virtual-template 1→ip add 24.0.0.2 255.255.255.252→ppp multilink; STEP4: In MLP, call the virtual template: R2/R4 (c) #multilink virtual-template 1after setting the virtual interface, the bandwidth doubles with #sh in Virtual-a 1: Interface address is 35.0.0.1/30 ... BW 3088 Kbit ...The MLP has 32-bit host routing on both ends (hostRoute):: C 12.0.0.1/32 is directly connected,serial 0;you can turn off the PPP host route interface serial 0→no peer Neighbor-route in the interface.
From for notes (Wiz)
3.1-hdlc/ppp
