Traffic Manager

Traffic Manager is DNS-based global traffic routing. It answers DNS queries with the best endpoint for each client according to a routing method, directing users to a region before any connection is made. Because it works at the DNS layer, it never sees the traffic itself — it only decides which address the client resolves.

That DNS-level operation is the key distinction from Front Door. Traffic Manager does not terminate connections, cache, or inspect traffic; it routes by handing out IPs. It suits non-HTTP endpoints and scenarios where DNS-level direction is enough, while Front Door is the choice when you want edge termination, caching, and a WAF in the data path.

Routing Methods

Several routing methods decide which endpoint a query resolves to: priority (active-passive failover), weighted (split traffic by ratio), performance (lowest-latency region for the client), geographic (route by the user's location, often for compliance), multivalue (return several healthy endpoints), and subnet (map client IP ranges to endpoints). The method encodes the routing policy in DNS responses.

Endpoint Monitoring

Traffic Manager probes endpoint health and stops returning unhealthy endpoints, so failover happens by removing a bad address from DNS answers. This is health-aware DNS, not a load balancer — it influences which endpoint clients resolve, but the clients connect directly to that endpoint afterward.

DNS-Based Limits

Because routing is DNS, clients and resolvers cache the answer for the record's TTL, so failover is only as fast as that TTL allows — a low TTL speeds failover but increases query volume. And once a client has resolved an endpoint, it connects there directly; Traffic Manager cannot redirect an in-flight connection or balance individual requests. These are the inherent limits of routing at the DNS layer.