3Design and Implement Routing

• 3.1System Routes and User-Defined Routes (UDR)

  Understand the system routes Azure provides automatically, user-defined routes (UDR) that override them, and the route table that bundles them. Controlling the "next hop" of traffic is the basis of routing.

• 3.2NVAs, Service Chaining, and Forced Tunneling

  Understand service chaining that routes through network virtual appliances (NVA) like firewalls, forced tunneling that forces outbound traffic through on-prem, and gateway sharing in hub-and-spoke. These are practical traffic controls built on UDRs.

• 3.3BGP and Route Propagation

  Understand BGP for dynamically exchanging routes between on-prem and Azure, route propagation over VPN/ExpressRoute, and route-selection precedence. Dynamic routing reduces manual route configuration.