What is the purpose of BGP router ID in VPN configurations?

The BGP router ID plays a crucial role in ensuring the successful establishment and operation of VPN connections. It is a unique identifier assigned to each BGP router, which allows for the clear differentiation of routers within a network.

In the context of VPN configurations, it is important for the router IDs to match on both the hub and the remote sites (FortiSASE) when establishing a VPN connection. This matching mechanism helps to ensure that routing information is correctly exchanged between the devices, facilitating effective communication within the VPN. When the router IDs match, it enhances the reliability and consistency of BGP operations, leading to a more stable connection overall.

This aspect of the BGP router ID being a prerequisite for successful VPN connections is fundamental in routing protocols, as it ensures proper identification and authentication between the communicating peers.