Norstar Telecom is configuring ExpressRoute Private Peering and must provide the Azure‑facing primary and secondary IPv4 subnets for the peering session. Which pair of subnet sizes and characteristics should they provide to satisfy Azure requirements for Private Peering primary/secondary subnets?

For ExpressRoute Private Peering, you must provide two distinct IPv4 subnets, one for the primary BGP session and one for the secondary BGP session. Each subnet must be at least a /30, which provides four addresses: network address, host 1, host 2, and broadcast address. Azure uses one host address, and your edge router uses the other for the point-to-point BGP connection. The example 192.168.100.0/30 and 192.168.100.4/30 correctly illustrates this requirement. Providing a single /16 or two /24 subnets is incorrect as Azure expects specific, small point-to-point subnets for the BGP sessions, not large address spaces. Azure does not automatically assign these addresses; you must provide them.