An on-premises datacenter must connect privately to Azure with predictable bandwidth and avoid traversal of the public internet. Which connectivity option should be recommended?
ExpressRoute provides private dedicated connectivity to Microsoft cloud services through a connectivity provider.
Why this answer
ExpressRoute provides a dedicated private connection from on-premises to Azure, bypassing the public internet entirely. It offers predictable bandwidth, low latency, and high reliability through a Layer 3 MPLS or direct fiber link from a connectivity provider. This meets the requirement for a private, consistent network path without internet traversal.
Exam trap
The trap here is that candidates may confuse Site-to-site VPN (which also provides a private IP tunnel) as meeting the 'private' requirement, but it still traverses the public internet and cannot guarantee predictable bandwidth like ExpressRoute.
How to eliminate wrong answers
Option A is wrong because Azure Bastion is a managed PaaS service for secure RDP/SSH access to Azure VMs over TLS, not a connectivity option for on-premises datacenters. Option B is wrong because Point-to-site VPN uses SSTP or IKEv2 over the public internet, which cannot guarantee predictable bandwidth and does traverse the internet. Option C is wrong because Site-to-site VPN only uses IPsec tunnels over the public internet, which introduces variable latency and bandwidth due to internet routing, failing the requirement for predictable bandwidth and no public internet traversal.