Technical Tip: Understanding BGP route flow and commands used in different locations

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Description	This article explains how the BGP routes propagate, how different routes are manipulated, and what commands are used in these locations.
Scope	FortiGate.
Solution	Below is a basic flow diagram of how BGP route propagation is done: BGP router is receiving BGP routes from its neighbor 1. If 'soft-reconfiguration' is enabled, it is possible to view the received route, before they reach the inbound policy. config neighbor    edit "10.200.2.2"       set soft-reconfiguration enable    next end Inbound policy is where route-maps are applied for incoming routes from the neighbor. After applying inbound policies, routes are sent to BGP table. The Best routes are sent to the Routing table. For outgoing routes,  it is possible to add outbound policies via route-maps and filtered routes will reach the other BGP neighbor 2. Different commands are used in places in the flow chart. Commands in {A, B, C, D, E} locations on the diagram will be shown below. [A] -  get router info bgp neighbors <neighbor-IP> received-routes [B] -  get router info bgp neighbors <neighbor-IP> routes [C] -  get router info bgp network        get router info bgp network <prefix> [D] -  get router info bgp neighbors <neighbor-IP> advertised-routes [E] -  get router info routing-table all        get router info routing-table database        get router info routing-table details <network> Outputs of these commands can be seen from this related article: Technical Tip: Use case of a Local preference and AS path prepending for route manipulation in BGP