Goldfish Networks wordmark
BeginnerPublished 2026-07-04

CCNA L1: Interface Addressing and Verification

Free preview — the first lab of IP Addressing & Subnetting

Beginner CCNA lab (1 of 10) focused on configuring and verifying IPv4 interface addressing on Cisco IOS routers. Learners assign given /24 addresses to two router interfaces and validate directly-connected reachability. No routing protocols or static routes are configured in this lab.

Track
Est. time
25 minutes
Difficulty
Beginner
Topics

Learning objectives

  • Configure IPv4 addresses and masks on IOS router interfaces using ip address <addr> 255.255.255.0
  • Bring interfaces administratively up using no shutdown
  • Verify interface state and addressing with show ip interface brief and show running-config interface
  • Validate directly-connected reachability with ping between neighbors and a host-to-gateway test

Troubleshooting focus

  • Interface remains administratively down or protocol down/down due to missing no shutdown or cabling error
  • Mask mismatch on a shared LAN prevents ARP/neighbor resolution
  • Host default gateway misconfigured, preventing host-to-gateway pings
  • Wrong IP assigned to the wrong interface (transit vs LAN)

Topology

Lab topology diagram

Related labs

More hands-on Cisco Modeling Labs practice on the same track and topics.

Study this topic

Free guides, a command cheat sheet, and graded practice for this lab's topic.

Learn Subnetting & IP AddressingWhat Is Subnetting? Subnetting Explained

Grade your work

How this lab is graded
  • Build it your way. Where a lab lets you choose a value — a VLAN name, an interface description — grading checks that you configured it, not which name you picked. Names that another line has to reference, like an ACL applied with access-class, are stated in the guide and do have to match.
  • Addresses, modes and protocol keywords are exact. An IP address, a subnet mask, switchport mode trunk, an encapsulation — these carry the meaning of the lab, so they are graded as written in the guide.
  • Grading reads your saved configuration. Export the lab from CML after you have configured it, and make sure anything you set is in the running-config — a change that only exists in a terminal session never reaches the grader.
  • You can submit as many times as you like. Your best score stands, and each attempt tells you which checks passed so you can work the gaps.
  • Scored something you believe is correct? Use Report an issue on this page — that is exactly how the grading fixes in the changelog got found.

Create a free account to submit your lab for grading.

Create a free account
Found a problem with this lab?

Please sign in to report a problem — tying it to your attempts lets us reproduce and fix it faster.