BingCo is configuring a Local Network Gateway (LNG) resource to represent its on-prem environment for a Site-to-Site VPN. The on-prem team has provided multiple networks (10.1.0.0/16 for datacenter, 10.2.0.0/16 for branch) and a BGP ASN of 65020 with a peering IP of 192.0.2.5. Which configuration in the Local Network Gateway is required to correctly represent the on‑prem environment for BGP-enabled S2S?

For a BGP-enabled Site-to-Site VPN, the Local Network Gateway (LNG) must accurately reflect the on-premises network configuration. This includes specifying all on-premises address prefixes that Azure needs to learn routes for, which are 10.1.0.0/16 and 10.2.0.0/16 in this case. Crucially, for BGP to function, the LNG also requires the on-premises BGP Autonomous System Number (ASN) and the BGP peering IP address. Therefore, setting bgpSettings.asn to 65020 and bgpSettings.bgpPeeringAddress to 192.0.2.5 enables Azure to establish a BGP session with the on-premises VPN device and dynamically exchange routes. The first incorrect option is wrong because consolidating to a single CIDR (10.1.0.0/15) is unnecessary and policy-based routing is not used with BGP. The third option is incorrect because the LNG must contain the on-prem prefixes for BGP to advertise them, and the BGP ASN for the on-prem environment is configured on the LNG, not the Virtual Network Gateway. The fourth option is incorrect because using 0.0.0.0/0 would route all traffic to on-prem, which is not the intent, and 65515 is a default Azure ASN, not the provided on-prem ASN.