MS-102 Deploy and manage a Microsoft 365 tenant Practice Question
You need to configure Microsoft Teams to allow external access for federation with another organization. The other organization uses a different domain. Which setting must you enable in the Teams admin center?
⚠ Common exam trap
Watch out — candidates often confuse Guest access (Microsoft Entra B2B) with External access (federation), leading them to select Option B, but Guest access is for individual external users, not for domain-level federation with another organization.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
External access with the domain of the other organization.
To enable federation with another organization that uses a different domain, you must configure External access (also known as federation) in the Teams admin center. Specifically, you need to add the external domain to the allowed domain list under Teams > External access. This allows users in your tenant to communicate with users in the other organization via Teams, using the Session Initiation Protocol (SIP) federation protocol.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Network roaming policy for the external users.
Why it's wrong here
A network roaming policy is entirely unrelated to permitting external users. In Microsoft Teams, this policy defines how IP subnets map to network regions, sites, and subnets for the purpose of location-based routing, particularly for PSTN calls. Misapplying it would have no effect on whether users from another organization can connect, and it does not control federation or domain allowlists.
- ✗
Guest access in Teams settings.
Why it's wrong here
Guest access in Teams settings allows you to invite individuals from outside your organization as guests, giving them access to channels, chats, and files under your tenant's identity and compliance policies. This is separate from federation (external access), where users retain their own home tenant credentials and communicate directly without being added as guests. Enabling guest access does not of itself federate with another domain, so it is not the right setting.
- ✗
Emergency calling policies.
Why it's wrong here
Emergency calling policies define the emergency numbers, call routing, and notification behavior for users within your tenant, such as how calls to 911 are handled and which numbers to translate. These policies have nothing to do with enabling cross-organization communication or allowing external domains to reach your Teams deployment. Configuring them would not establish the federation required for external access.
- ✓
External access with the domain of the other organization.
Why this is correct
External access (federation) is the correct mechanism to let users in your organization communicate with users from a different organization in Teams. In the Teams admin center, under External access, you can allow federation globally or restrict it to specific domains by adding the other organization's domain to the allowed list. This setting enables chat and calls between your users and those in the external tenant, while keeping each user in their own organization's identity.
Go deeper
Related to this question
Learn chapter
Microsoft 365 Tenant Setup
Key term
Federation
Federation is a system that lets you use one set of login credentials (like your work email and password) to access resources across different organizations or services without needing separate accounts for each one.
Key term
Microsoft Teams
Microsoft Teams is a collaboration platform that integrates chat, video meetings, file storage, and application integration into a single workspace, primarily used within the Microsoft 365 ecosystem.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This MS-102 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the MS-102 exam.