Notes on the fourth day

Physics line --- 1, cost ;2, Geographical constraints

 

VPN--- Virtual private network
VPN The core of Technology --- Tunnel technology --- Packaging technology

GRE--- Generic routing encapsulation

The way we want to go
SIP: 192.168.1.1 DIP:192.168.2.1 data

The real way
SIP: 12.0.0.1 DIP: 23.0.0.2   data
SIP:12.0.0.1  DIP:23.0.0.2  GRE  SIP:192.168.1.1   DIP:192.168. 2.1   data  

Tunnel technology --- At both ends of the tunnel, a data channel is established in the public network through encapsulation and de encapsulation , Use this data channel for transmission .

GRE Configuration method :                                                                                                                               .

1. Create a tunnel interface

[r1]interfaceTunnel0/0/0                                                                                                                    

[r1-Tunnel0/0/0]

2. Interface configuration IP Address

[r1-Tunnel0/0/0]ip address192.168.3.124

3. Define encapsulation method
[r1-Tunnel0/0/0]tunnel-protocol gre

4. Define the content of the package

[r1-Tunnel0/0/0]source 12.0.0.1

[r1-Tunnel0/0/0]destination 23.0.0.2

NHRP--- Next - Hop Resolution Protocol ---NHS--- Next - Jump to the resolution server --- principle : You need to select a device with a fixed exit physical address in the private network as NHS, All remaining branches should know the tunnel address and physical address of the center , then ,NHRP All branches are required to integrate their own physical interfaces and tunnel interfaces IP The mapping relationship of the address is sent to NHS, If the physical address changes , You need to resend . such NHS You can get the mapping relationship of the addresses of all branches . If the branches need to communicate with each other , You need to apply to the center to obtain the mapping relationship table --- This architecture is called hub-spoke framework .

MGRE Configuration of

Configuration of the center :

        1. Create a tunnel interface

[r1]interfaceTunnel0/0/0                   [r1-Tunnel0/0/0]

        2. Interface configuration IP Address

Tr1-Tunnel0/0/0lip address192.168.3.124

        3. Define encapsulation method

[r1-Tunnel0/0/0]tunnel-protocol gre p2mp

        4. Define the content of the package

[r1-Tunnel0/0/0]source 15.0.0.1

        5. establish NHRP Domain

[r1-Tunnel0/0/0]nhrp network-id 100

Configuration of branches :
        1. Create a tunnel interface
[r1]interface Tunnel0/0/0[r1-Tunnel0/0/0]

        2. Interface configuration IP Address
[r1-Tunnel0/0/0]ip address 192.168.3.124

        3. Define encapsulation method
[r1-Tunnel0/0/0]tunnel-protocol gre p2mp

        4. Define the content of the package
[r2-Tunnel0/0/0]sourceGigabitEthernet0/0/1

        5. Join the center to create NHRP domain
[r2-Tunnel0/0/0]nhrp network-id100

        6. Report information to the center
[r2-Tunnel0/0/0]nhrp entry 192 168.5.115.0.0.1 register
                                              Tunnel address         Physical interface address

[r1-Tunnel0/0/0]display nhrp peer all--- see NHRP Registration of neighbors

MGRP Environment when sending data , It is still a point-to-point tunnel , So data transmission is still point-to-point transmission . therefore ,MGRE The environment is similar to NBMA Environment .

RIP Realization MGRE Environmental problems :

1, Only the center gets the routing information of the branch , And the branch did not get to start the pseudo broadcast on the center
[r1-Tunnel0/0/0]nhrp entry multicast dynamic
2, After the center turns on the pseudo broadcast , The branch can only receive the routing information of the center , But there are no branches .
        reason ---RIP The horizontal segmentation mechanism of
        resolvent :[r1-Tunnel0/0/0]undo rip split-horizon--- close RIP The horizontal division of

OSPF--- Open shortest path first protocol

        Lu Jia Xuan , Fast convergence , Less occupied resources

RIP Version of ---RIPV1,RIPV2---IPV4
                    RIPNG---IPV6
OSPF Version of ---ospfv1( Days off in the Laboratory ),ospfv2---IPV4
                        ospfv3--- IPV6

RIPV2 and OSPFV2 Similarities :

        1.RIPV2(224.0.0.9) and ospfv2(224.0.0.5,2240.0.6) They all send information in the form of multicast .----224.0.0.X The multicast address of --- Local link multicast ---- TTL Set to 1

        2.RIPV2 and OSPFV2 Are called classless routing protocols .

        3.OSPFV2 and RIPV2 All support manual authentication

        4.OSPFV2 and RIPV2 All support equal overhead load balancing

RIP and OSPF Difference point :

RIP It can only be used in small networks ,OSPF It can be applied to medium and large networks --- OSPF Support structured deployment --- Zoning --- Purpose -- Transfer topology information within the region , Transfer routing information between regions .

OSPF If the network has only one area , Such a network is called a single area OSPF The Internet ; If there are multiple areas , It is called multi region OSPF The Internet .

Area border router ---ABR--- Belong to multiple areas at the same time , An interface corresponds to an area , And there is an interface in the area 0 in .
There can be multiple... Between regions ABR equipment , One ABR It can also correspond to multiple regions .

Requirements for area division ---1. There must be... Between areas ABR equipment
                             2. Region division must be based on star topology --- The middle region of star topology is called backbone region .

Area ID(areaID)--- Distinguish and calibrate ospf Different areas in the network ---32 Bit binary structure ----

1. Dotted decimal means ;

2. Use decimal system directly to express ---- The backbone area ID Defined as area 0.

1.OSPF Data packets of

hello package --- Cycle discovery , Building and keeping neighborhoods alive
        hello Time ---10S(30S)
        Dead time---4 Times hello Time

        RID---1, The whole network is unique ;2, use the same pattern --- Must follow IP Address format to design , from 32 Bit binary structure .
        1. Manual configuration --- Just meet the above two conditions                                                                                            2. Automatic generation ---
                1. First, check whether the device is equipped with a loopback interface , If it exists, select the loopback interface IP Address as RID; If there are multiple loopback interfaces , Then the one with the largest value will be selected as RID.
                2. If there is no loopback interface , Then the... Of the physical interface of the device will be taken IP Address as RID, If there are multiple physical interfaces , Then the one with the largest value will be selected as RID.

DBD package --- Database description message ---LSDB( Link state database )---LSA--- Link status notification

LSR package --- Link status request message --- according to DBD Package comparison , Jigan local god knows LSA Message sending request .

LSU package --- Link state update message --- Really carry LSA Packets of information

LSAck package --- Link status acknowledgement message

OSPF There is 30min A periodic update .

2.OSPF State machine

 TWO-WAY--- It marks the establishment of neighbor relations

 

( Matching conditions ) The match is successful , Then you can enter the next state , If you fail , Will stay in the neighborhood , Use only Hello The package is kept alive periodically .

 

Principal subordinate relationship election --- By comparison RID To carry out ,RID Big for the main , The master can enter the next state first .--- Use here DBD Package to complete the master-slave relationship election is mainly to distinguish from the previous neighbor state .