BGP is the standard routing protocol that is used to exchange routing and presence information between multiple networks on the internet.

In the context of virtual Azure networks, Azure VPN gateways and your local VPN devices (BGP peers or neighbors) can use BGP routes to exchange information about the availability and availability of the prefixes that the involved gateways or routers pass through.

BGP also allows transit routing between multiple networks. For this purpose, determined routes of a BGP peer are passed on to all other BGP peers.

In the Azure networking area, routing with BGP is used with Azure Site-to-Site and Azure ExpressRoute connections.