Lesson 11 — Topology Design | Learn OpenID Federation

What Is a Federation Topology?

A federation topology describes the shape of trust relationships — how Trust Anchors, Intermediates, and Leaf Entities are organized and connected. The right topology depends on your scale, governance model, and resilience requirements.

Explore Topology Patterns

Single Anchor

Pros:

Simple to manage
Short trust chains

Cons:

Single point of failure
Doesn't scale beyond small federations

Step-by-Step Topology Design

Step 1 of 7

1. Identify the Problem

What trust problem are you solving? Cross-org auth? Multi-sector interop? Scale of participants?

Anti-Patterns to Avoid

Single Point of Failure

Fix: Use multi-anchor or standby anchor.

Overly Deep Chains (5+ levels)

Fix: Keep 2-3 levels. Use max_path_length constraints.

Unrestricted Intermediates

Fix: Always set naming_constraints on subordinate statements.

Policy Conflicts Between Paths

Fix: Use subset_of/one_of instead of hard value operators.

Ignoring Key Rotation

Fix: Plan rotation schedules. Use the Historical Keys endpoint.

Real-World Analogy

Designing a federation topology is like designing a national postal system. Do you have one central sorting office (single anchor) or regional hubs (hierarchical)? Do you connect international networks through a bridge? Same trade-offs: speed, resilience, and cost.