Goldfish Networks wordmark
IntermediatePublished 2026-08-17

CCNA Foundations: Dual-Stack — Both Protocols, One Network

Archive lab

Build a compact dual-stack enterprise topology where IPv4 is already forwarding end-to-end using OSPFv2. Your task is to bring up IPv6 routing in parallel using OSPFv3 with explicit router-ids, proving that IPv6 control/data planes operate independently from IPv4. Verify both protocols resolve separately and that an IPv4 control-plane failure does not impact IPv6 forwarding.

Track
Est. time
85 minutes
Difficulty
Intermediate
Topics

Learning objectives

  • Enable IPv6 forwarding on Cisco IOS routers with ipv6 unicast-routing
  • Deploy OSPFv3 with explicit router-ids and per-interface activation
  • Validate separate IPv4 and IPv6 RIBs and neighbor adjacencies
  • Prove that IPv6 remains up when IPv4 control-plane is impaired
  • Use host-based verification (ping/ping6) and IOS show commands to confirm reachability

Troubleshooting focus

  • No IPv6 routing: ipv6 unicast-routing missing on any router prevents IPv6 forwarding
  • OSPFv3 process not starting: missing router-id under ipv6 router ospf
  • No OSPFv3 adjacency: per-interface ipv6 ospf <pid> area <n> omitted or wrong area
  • Wrong/mismatched IPv6 prefix lengths on links
  • Hosts default gateway set to wrong IPv6 address

Topology

Subscribe to preview this lab's topology.

See plans

Related labs

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

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.