Route Processing on the BGP router

Figure 1 shows the route processing on the BGP router. BGP routes can be imported from other protocols or learned from BGP peers. Route summarization can be configured to reduce the routing table size before routes are selected, advertised, and delivered to the IP routing table.

Figure 1 Route processing on the BGP router

Table 1 lists some key points for Figure 1.

**Table 1** Key points for route processing
No.	Remarks
1	BGP can import direct routes, static routes, user network routes, and IGP routes based on the import-route (BGP) or network command configuration.
2	BGP can use routing policies when importing routes from other protocols, receiving routes from BGP peers, or advertising routes to BGP peers. Routing policies can be used to filter routes or modify route attributes.
3	BGP supports automatic and manual summarization. Multiple routing policies can be used during manual summarization.
4	BGP selects routes based on strict route selection rules, which is the key point to be discussed in the following part.
5	BGP adds the optimal route to the BGP routing table and advertises it to BGP peers.
6	BGP adds the routes learned from peers and the optimal route in the BGP routing table to the IP routing table for traffic forwarding.