Community QuestionSeen on 8 CBTs
NetBIOS (Network Basic Input/Output System)
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Answer
Ports 137, 138, 139
4 of 8 indexed CBT versions give this answer·Answer index rebuilt Aug 16, 2026
The indexed versions don't agree on this one
This question appears on 8 CBT versions we've indexed, and they don't all give the same answer. Exam editions change and answer keys get re-cut, so more than one of these was correct on the test it came from. Here is each of them, and how many versions give it.
4 of 8 versionsmost versions
Ports 137, 138, 139
Comptia A+ Port Numbers · Comptia Port Numbers · Comptia Ports · +1 more
3 of 8 versions
tcp/139 NetBIOS session service Windows connection-oriented data transfer
Comptia A+ Course Notes · Comptia A+ Notes · Comptia Notes
1 of 8 version
linux and macs to connect to windows networks.
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