IntermediatePublished 2026-07-02
Securing HSRP with MD5
Bundle lab
Lab 5 of 13 in First-Hop Redundancy (HSRP & VRRP) · ← Previous · Next →
CCNA exam domain: IP Connectivity
Harden an HSRP virtual default gateway with MD5 authentication so only trusted routers can participate. You’ll secure an existing HSRP group on two IOS routers that share a user VLAN via a single L2 switch. Validate the authentication state on both routers and confirm the endpoint still reaches the virtual IP.
Learning objectives
- Explain why unauthenticated HSRP can be hijacked by a rogue router
- Configure HSRP MD5 authentication on both peers with a matching key-string
- Verify HSRP authentication state and active/standby roles with show standby
- Confirm end-host reachability to the virtual default gateway
Troubleshooting focus
- HSRP peers remain in Init or Speak due to mismatched authentication key-string
- Incorrect HSRP group number or virtual IP prevents the pair from forming
- End host default gateway set to a physical router IP instead of the virtual IP
Topology
Subscribe to preview this lab's topology.
See plansGrade 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 accountFound a problem with this lab?
Please sign in to report a problem — tying it to your attempts lets us reproduce and fix it faster.