Multi-region ospf and virtual connections, and Remote Areas

PS: ospf route table creation process: www.2cto.com summary: neighbor table two-way mode --> full state --> Use ospf algorithm --> route table 1, create neighbor table --> stable to reach two-way mode; 2. Select DR and BDR [priority and Router ID, whichever is big] to solve the problem of who said it first in the region; 3. First send type 1: Hello message; 4. Each sends a DBDO (Database description) packet, which belongs to type 2 in the OSPF protocol datagram. the type 1 packet is a Hello packet; 5. Each sends a Response Validation packet LSAck, it means to receive, and then send the LSR [send the LSR packet to the router that initiates the DD, request the LSR packet that does not exist or is aging in the database] by comparing the respective lsdb, 6. Send LSU (link status update) based on the other party, and then send the LSAck message. --- Eventually reaches the full state, and then according to the ospf algorithm -- get the route table experiment topology: Experiment requirements: 1. for example, the experimental topology diagram R1 and R2 belong to the ospf Region 0, R2 and R3 belong to the ospf region 1, R3 and R4 belong to the ospf Region 2, and R2 and R5 adopt the rip Protocol; 2. use virtual connection to connect area2 and area0 through area1. 3. route table reduction is achieved by setting a remote route and a full remote route. 4. achieve network-wide interconnection. Note: device models: R1, R2, R3: R2661; R4, R5: S35265E. Experiment configuration: for example, the ip address planned in the experiment topology is slightly configured. Www.2cto. com1. R1 configuration: [R1] ospfenStartOSPFtask... OSPFenabled [R1-ospf] inters1 [R1-Serial1] ospfen?ea0 [R1-Serial1] intere0 [R1-Ethernet0] ospfen?ea02, R2 Configuration: [R2-ospf] inters1 [R2-Serial1] ospfenstmea0 [R2-Serial1] [R2-Serial1] inters0 [R2-Serial0] ospfenstmea1 [R2-ospf] imporip # publish rip Protocol route to ospf [R2-ospf] impodirect # publish direct connection route table information [R2-ospf] quit [R2] rip [R2-rip] network192.168.5.0 [R2-rip] intere0 [R2-Ethernet0] ripversion2 # Set rip Version type 2 [R2-rip] impoospf # Release ospf protocol route to rip [R2-rip] impodirect # publish route table information for direct connection 3. R3 configuration [R3] ospfenaStartOSPFtask... OSPFenabled [R3-ospf] intes0 [R3-Serial0] ospfenstmea1 [R3-Serial0] intere0 [R3-Ethernet0] ospfen?ea24, R4 configuration [R4] vlan2 [R4-vlan2] [R4-vlan2] porte0/1 [R4-vlan2] intervlan2 [R4] interLoopBack1 [R4-LoopBack1] ipaddress192.168.4.1255.109255.0 [R4] ospf [R4-ospf] area2 # Region 2 [R4-ospf-area-0.0.0.2] network192.168.3.10.0.0.0 # Declaring network segment [R4-ospf-area-0.0.0.2] network192.168.4.00.0.0.255 [R4-ospf-area-0.0.0.2] 5, R5 configuration [R5] vlan2 [R5-vlan2] porte0/1 [R5-vlan2] intervlan2 [R5-Vlan-interface2] [R5-Vlan-interface2] ipaddres192.168.5.21_255.255.0 [R5] interlo [r5] interLoopBack1 [R5-LoopBack1] [R5-LoopBack1] ipadd192.168.6.2104255.255.0 [R5] rip [R5-rip] network192.168.5.255.0.0.0 [R5-ospf-rip] network192.168.6.255.0.0.0 [R5] intvlan2 [R5-Vlan-interface2] ri Pver2 # declare that the rip version type is 2. After you view R4, you can find that it cannot learn routes in area 1 and Area 2 through ospf, through virtual connection establishment, virtual connection establishment 1. view the RouterID Number of R3 and R2: [R3-ospf] disospfRouterID: 192.168.3.2BorderRouter: AreaRoutingselectionpreference: Inter/Intra: 10 External: 150 DefaultASEparameters: metric: 1Tag: 1 Type: 2 SPFcomputationcount: 102, run: configuration in R2: [R2] ospf [R2-ospf] vlinkpeer-id192.168.3.2transit1 configuration in R3: [R3] ospf [R3-ospf] vlinkpeer-192.168.1.1transit-area13, after creating a virtual, log on to R4 to view the route table It is found that the routes between domains and external networks can be learned. 4. Check the related attributes of R2 and R3ospf. It is found that the RouterID of R2 under virtuallinks is 192.168.2.2, that is, the s0 interface of R3; the RouterID of R3 is 192.168.1.1, that is, the s1 interface of R2. After a virtual connection is established, it is found that there are too many route table items. If area2 is used as the destination region, the information of type 5 will not be accepted, and the default route will be replaced; remote Area 1. Remote Area 5 (LSA) is not accepted, that is, external routing. 2. The default route 0.0.0.0/0 is automatically transmitted to the remote area through the API in the remote area; 3. routes between regions are acceptable in the final area. R3 settings: [R3] ospf [R3-ospf] stubcost80area2 R4 settings: [R4] ospf [R4-ospf] area2 [R4-ospf-area-0.0.0.2] stub view the route table entry for R4 in the last section, only inter-region routes and direct routes are found: complete sub-region 1. External routes and inter-region routes are not accepted; 2. Only routes in the last region and a default route injected by the ABR to the region are available. [R3-ospf] After the stucost80area2no-summaryAreahasbeensetasstubarea is set to the full detail area, view the R4 route table entry with only one default route: and perform the pingR5 test,