Basic knowledge about vro technology: Practical Application of Dynamic and Static vro protocols

With the development of the routing industry, both the router technology and the routing protocol are constantly improved, making the routing technology more standardized, the previous lecture on VPN routing and forwarding focuses on configuring and verifying VRF (VPN route forwarding. In the above circumstances, users must be isolated from a shared device. In that article, I did not define the communication mode between each user outside the shared interface, such as Static Routing Protocol or dynamic routing protocol.

Situation Review

Let's review the situation of small service providers I have introduced in several recent articles. A shared device connects two users (User A and user B) on the edge of A provider network (PE) to provide Internet access. Each user must be isolated, and each user must be able to broadcast to the subnet after their own router technology. Last week, I introduced how to set two VPN routing protocols and forwarding (VRF) instances, and allocated user A and user B to A single interface of each VRF.

Static Routing

The Static Routing Protocol is a manual method through which a next hop router "points to" A route prefix (subnet. Traditional static routing is used in small networks using low-power router technology. This method saves the power of the processor and eliminates the need to converge such a dynamic mechanism. The following example shows how to add a static route: Router_A (config) # ip route 10.1.1.0 255.255.255.0 192.168.1.1

This command defines the 10.1.1.0/24 network as the network that can be accessed through the next hop vro of 192.168.1.1. The relationship between router A and the next hop router is not described here. Remember that the next hop can be accessed without a route. If this is correct. But what about VRF? This command only adds a Static Routing Protocol to the global routing table. To set a static route in VRF, run the following command: Router_A (config) # ip route vrf VRF_A 10.1.1.0 255.255.255.0 192.168.1.1, this command adds the same Static Routing Protocol to VRF. To verify the validity of this entry, run the following command: Router_A # show ip route vrf VRF_A. The entered route should be in the VRF routing table, and the "S" label representing the static state should be written.

Dynamic Routing

Different from static routing protocols, dynamic routing uses various protocols to automatically publish routing information between "same" router technologies. This Protocol includes OSPF and RIP. To set OSPF, run the following command: Router_A (config) # router ospf 1; Router_A (config-router) # network 192.168.1.0 0.0.0.3 area 0.0.0.0

These commands can start OSPF on router A at least. Vroa A's interface is set for the 192.168.1.1 network. The second command places a special interface in Area 0 (OSPF Backbone Network. Any OSPF router with the same network command will form an adjacent space and route information will be published. To verify any learned routing protocol, run the following command: Router_A # show ip route or Router_A # show ip route ospf, which is the same as the Static Routing Protocol, this setting starts OSPF for the route in the global route table. What should we do if we want to expand to the display topology? In this case, the customer's router and the router technology of the service provider must start OSPF within the VRF. Run the following command to complete the task:

Router_A (config) # router ospf 1 vrf VRF_A
Router_A (config-router) # network 192.168.1.0 0.0.0.3 area 0.0.0.0
Router_A (config-router) # capability vrf-lite
Router_ B (config) # router ospf 1 vrf VRF_ B
Router_ B (config-router) # network 172.16.1.0 0.0.3 area 0.0.0.0
Router_ B (config-router) # capability vrf-lite
SP_Router (config) # router ospf 1 vrf VRF_A
SP_Router (config-router) # network 192.168.1.0 0.0.0.3 area 0.0.0.0
SP_Router (config-router) # capability vrf-lite
SP_Router (config) # router ospf 2 vrf VRF_ B
SP_Router (config-router) # network 172.16.1.0 0.0.0.3 area 0.0.0.0
SP_Router (config-router) # capability vrf-lite

This command table will start OSPF in each VRF for all routers and allow route communication to start. The capability vrf-lite Command needs to be used to obtain the exact number of VRF route tables, as discussed in the Internet Protocol draw.ietf-ospf-2547-dnbit-04.txt. This draft is beyond the scope of this article. To verify that your adjacent space is composed and the routing protocol will be received, you can use the following command:
SP_Router # show ip ospf neighbor
SP_Router # show ip route vrf VRF_A
SP_Router # show ip route vrf VRF_ B
SP_Router # show ip vrf