Home > Glossary > Certified Network Associate > Administrative Distance (AD)

📖 What is Administrative Distance (AD)?

A value used by Cisco routers to select the best path when there are two or more different routes to the same destination from different routing protocols.

🥋 Sensei Says:

"A standard static route has a default AD of 1. A directly connected interface has an AD of 0. Remember this for floating static route questions!"

📚 Certification: Certified Network Associate (200-301)

🔑 What are the Key Concepts of Administrative Distance (AD)?

  • Route believability
  • Tie-breaker for different routing protocols
  • Cisco proprietary metric (mostly)

🎯 How does Administrative Distance (AD) appear on the 200-301 Exam?

Determining which route will be placed in the routing table when OSPF, EIGRP, and static routes all exist for the same destination.

Manipulating AD to prefer a specific routing path.

❓ Frequently Asked Questions

What is the AD of a static route?

The default AD of a static route is 1, making it highly preferred over dynamic routing protocols.


Can you change the AD of a dynamically learned route?

Yes, administrators can change the AD of routes learned via protocols like OSPF or EIGRP, though it's typically used for advanced traffic engineering.

Related Terms from Certified Network Associate

📝 Related Study Guides

Cisco CCNA 5 min read

Understanding the OSI Model: A CCNA Guide

The OSI model is a conceptual framework with 7 layers (Application, Presentation, Session, Transport, Network, Data Link, Physical) that standardizes telecommunication functions.

Cisco CCNA 4 min read

TCP/IP vs OSI Model: Key Differences for CCNA

The OSI model has 7 layers used for theoretical understanding, while the TCP/IP model has 4 layers (Application, Transport, Internet, Network Access) and reflects protocols actually used on the internet.

Cisco CCNA 6 min read

IPv4 Addressing Basics: A Beginner's Guide

An IPv4 address is a 32-bit logical address written in dotted-decimal format, divided into a network portion and a host portion by a subnet mask.

🧠

Test Your Knowledge

Think you understand Administrative Distance (AD)? Put it to the test with our practice exam.

Try 10 Free Questions

⭐ 1,000 expert-curated questions available with Premium

Upgrade Premium