mission details
As a company continues to expand, the number of routers increases from the original basis. When network administrators find that the original routing protocol is no longer suitable for the existing network environment, they can implement dynamic routing OSPF protocol configuration to achieve mutual communication between all hosts in the network. Because the dynamic routing OSPF protocol can achieve rapid convergence and is unlikely to cause loops, it is suitable for medium-sized and large enterprise networks.
Mission requirements
(1) Configure dynamic OSPF routing to achieve network connectivity. The network topology is as shown in the figure
(2) The end IP addresses of routers and switches are as shown in the table
(3) The IP address, subnet mask and default gateway of each computer, as shown in the table
(4) Realize dynamic routing OSPF protocol configuration and achieve network-wide interoperability.
Knowledge preparation
1. OSPF protocol concepts
Open Shortest Path First (OSPF) protocol is an open standard protocol developed by the IETF organization. It is one of the most widely used routing protocols in the network. It is a link state interior gateway routing protocol that runs OSPF. The router of the protocol will send the link status information it owns to other OSPF protocol devices through the port with the OSPF protocol enabled. Each device in the same OSPF protocol area will participate in the creation, sending, receiving and processing of link status information. Forward until all OSPF protocol devices in this area obtain the same link status information.
2. OSPF protocol area An OSPF protocol network can be divided into multiple areas (Area). If an OSPF protocol network contains only one area, it is called a single-area OSPF protocol network; if an OSPF protocol network contains multiple areas, it is called a multi-area OSPF protocol network. In the OSPF protocol network, each area has a number called area ID (Area ID). The area ID is a 32-bit binary number, generally represented by a decimal number. The area with area ID 0 is called the backbone area, and other areas are called non-backbone areas. A single-area OSPF protocol network contains only one area, which is the backbone area. In a multi-area OSPF protocol network, in addition to the backbone area, there are several non-backbone areas. Generally speaking, each non-backbone area needs to be directly connected to the backbone area. When the non-backbone area is not directly connected to the backbone area, use Virtual Link technology logically realizes direct connection between non-backbone areas and backbone areas. In other words, communication between non-backbone areas must be relayed through the backbone area. To create an OSPF routing process, you can execute the following command in global command configuration mode.
It should be noted that the process number ranges from 1 to 65 535. The process number on each router in the network can be the same or different. In Huawei routers, when using the OSPF protocol, network is followed by the directly connected network segment and the corresponding anti-mask.
3．Link status and link status notification OSPF protocol is a routing protocol based on link status. Link status can also refer to the port status of the router. The core idea is that each router reports the port status of each of its own ports ( link status) is shared with other routers. On this basis, each router can calculate the route to each destination based on its own port status and the port status of other routers. The link status of the router includes information such as the IP address and subnet mask of the port. Link-State Advertisement (LSA) is the main carrier of link state information. Link state information is mainly included in LSA and is shared through LSA advertisement (flooding). It should be noted that different types of LSA contain different contents, functions, and advertising scopes. The main types of LSA are Type-1 LSA (Router LSA), Type-2 LSA (Network LSA), and Type-3 LSA. (Network Summary LSA) and Type-4 LSA (ASBR Summary LSA), etc. Due to the limited knowledge scope of this book, the types of LSA will not be explained in detail.
Task implementation
1. Refer to the figure to build the network topology, add the 2SA module to the router at the Serial1/0/0 position, use the Serial serial port line for the connection between the routers, and use straight-through lines for the others. Turn on the power of all devices and set up each computer. Corresponding IP address and subnet mask.
2. Configure the port IP address and other parameters of the switch and router. Configure the port IP address and other parameters of the switch and router. For specific configuration methods, please refer to the basic configuration of SW3A, R1 and R2 in Task 3.5 of this project.
3. Configure the dynamic routing OSPF protocol to achieve network-wide interoperability.
(1) Routing configuration of SW3A. The directly connected networks on SW3A are 192.168.2.0, 192.168.10.0 and 192.168.20.0, so the following dynamic routing OSPF protocol needs to be added.
(2) Routing configuration of R1. The directly connected networks on R1 are 192.168.1.0 and 192.168.2.0, so the following dynamic routing OSPF protocol needs to be added.
(3) Routing configuration of R2. The directly connected networks on R2 are 192.168.0.0 and 192.168.1.0, so the following dynamic routing OSPF protocol needs to be added.
Task acceptance
1. On R1, use the display ip routing-table protocol ospf command to view OSPF routing information.
2. On R2, use the display ip routing-table protocol ospf command to view OSPF routing information.
3. Use PC1 to ping the IP addresses of PC2 and PC3. You can see that they are connected.
Task summary
(1) When using the dynamic routing OSPF protocol to declare a directly connected network segment, use the anti-mask of the network segment.
(2) First specify the area to which the network segment belongs, and then declare the directly connected network segment.