In the network structure, we have been paying attention to their deployment and optimization. As the network pressure increases, we have put forward higher requirements for some hardware and protocols. Now, we will focus on the deployment of BGP routing protocols. In general, the BGP routing protocol deployed in the domain should consider the following:
1. Actual network topology;
2. Whether the device performance meets the requirements for enabling BGP. Generally, the BGP Route table is very large, increasing from 50,000 to more than 100,000. This has high requirements on the memory and performance of the router;
3. the backup and traffic distribution of multiple INTERNET access lines 。
Here are some examples to illustrate these issues. Before continuing the discussion, we should first mention several concepts:
Core layer: a backbone network with high-speed switching capability located at the core of the network 。
Distribution layer: on the periphery of the core layer, it is usually used to implement various routing policies or implement access control 。
Access layer: In the outermost layer of the network, the router in this range is the access point connecting the user to the ISP 。
In the early stages of network development, the network structure is relatively simple (1). ISP only has one line to connect to the INTERNET. Generally, BGP is not used in this simple network structure, in this way, you can use simple and convenient static routes for interconnection. This simplifies router configuration, facilitates management, and reduces performance requirements and costs for vbrs 。
To enable BGP, you only need to enable the BGP routing protocol on router R1 and use R1 as the default gateway of other routers in the network to inject external routes into the network 。