Networking
CoreAzure route tables and effective routes
User-defined routes, next hops, propagation, and effective route evaluation.
Key points
- Route tables hold user-defined prefixes and next-hop types and associate with subnets.
- Effective routes combine system, peering, propagated, and user-defined sources for a NIC.
- Longest-prefix match selects the most specific destination route.
Best-known use cases
- Send a subnet’s on-premises traffic through an appliance.
- Diagnose why a VM selected an unexpected next hop.
What candidates often confuse it with
- UDR vs NSG: direct traffic vs filter traffic.
- Configured route table vs effective routes: one input vs combined applied path state.
Key takeaway
Use effective routes to prove the selected path before changing a subnet route table.
Related services
- Azure Network Watcher
Relevant exam tasks
- D4.1.S4 — Configure user-defined routes
- D4.1.S5 — Troubleshoot network connectivity