intermediate·20 min·Paid

Overly Broad Firewall Rule

Monitoring system flags guest Wi-Fi reaching the payroll server

Scenario

The security monitoring platform flagged an anomaly: a device on the guest wireless network successfully connected to the payroll application server. That should not be possible under company policy — guest Wi-Fi is only supposed to reach the Internet, nothing internal. Investigate how this is happening and lock it down without breaking guest Internet access or legitimate employee access to payroll.

Learning objectives

  • acl
  • nftables
  • least privilege

Topology and configuration

This environment contains 5 devices (4 Hosts, 1 Router). You configure and troubleshoot the networking skills listed above.

Curriculum topics

Environment

Subnetica labs run FRRouting and Linux networking with Cisco-like syntax, not Cisco IOS. Commands and behavior may differ from Cisco devices.

Addressing is regenerated on every attempt and the environment is graded automatically.

Ready to practice?

Sign in or create an account before launching this lab. Viewing this preview never starts or reserves infrastructure.

subnetica© 2026 · Learn, practice, retain.
CCNA is a registered trademark of Cisco Systems, Inc. CompTIA Network+ and CompTIA Security+ are registered trademarks of CompTIA, Inc. Subnetica is an independent learning platform and is not affiliated with, endorsed by, or sponsored by Cisco Systems, Inc. or CompTIA, Inc.