Which protocol has the highest administrative distance?

N10-009 By islever Editorial Last updated

Explain common networking ports, protocols, services, and traffic types. Explain characteristics of routing technologies.

Short answer

B Border Gateway Protocol has the highest administrative distance at 200 for internal routes.

Question

Which of the following has the highest administrative distance?
  1. Enhanced Interior Gateway Routing Protocol
  2. Border Gateway Protocol Correct Answer
  3. Static route
  4. Open Shortest Path First

Key Takeaways

Remember that lower administrative distance means higher trust. BGP's high AD (200 for iBGP) makes it the least preferred source when multiple paths exist.

Border Gateway Protocol (BGP) has the highest administrative distance (200) among common routing protocols, making it less trusted than static routes, EIGRP, or OSPF.

Common mistake: Choosing Static Route because it has the lowest AD (1) and is most trusted. The question asks for the *highest* AD, meaning the *least* trusted source.

Expert Analysis

Administrative Distance Values

Administrative distance (AD) is a Cisco proprietary scale used to rate the trustworthiness of routing information sources. The lower the AD, the more reliable the route source.

  • Static Route: 1
  • EIGRP: 90
  • OSPF: 110
  • BGP: 20 (External), 200 (Internal)

The question asks for the highest administrative distance among the options provided. Since BGP has an internal AD of 200, which is higher than all other options, it is the correct answer.

Exam Strategy

Memorize the default administrative distance values for common routing protocols. Focus on the extremes: Static (1) is most trusted, while BGP Internal (200) is least trusted. When a question asks for 'highest' or 'lowest' AD, quickly recall these benchmarks to eliminate wrong answers.

Frequently Asked Questions

What is the administrative distance of a static route?

A static route has an administrative distance of 1, making it the most trusted routing source by default.

Why does BGP have such a high administrative distance?

BGP has a high AD (200 for iBGP) because it is designed for policy-based routing across different autonomous systems, where manual configuration and policy are prioritized over automatic preference.

More N10-009 FAQ →

Community Votes

D
100%

100% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 1 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 1

  1. ERB14 👍 1 Answered D
    Static route: AD = 1 External BGP (eBGP): AD = 20 EIGRP (Internal): AD = 90 OSPF (Open Shortest Path First): AD = 110

Reader comments & corrections

No reader corrections yet — spotted an error or have a note? Share it below.

Log in to comment, report an error, or add a note about this question.

Why does a moved 2.4GHz WAP cause intermittent laptop issues?

S-grade

How to Reduce Network Congestion and Improve Performance?

S-grade

Why did the telephone system lose connection with a working console and module access?

S-grade

What is the transport layer transmission format for connectionless communication?

S-grade

Practice All N10-009 Questions

Access 100 questions with complete answers and detailed explanations.

View Full N10-009 Practice Test →

← Back to N10-009 Study Guide