CCNA IP Routing Practice Question
Network Topology
You are connected to R1 via console. The network has a primary link to the ISP via R2 and a backup link via R3. Configure IPv4 and IPv6 floating static default routes on R1 so that the primary path goes through R2 (AD 1) and the backup through R3 (AD 10). Additionally, configure a static route on R1 for the internal LAN 192.168.10.0/24 via R2 (AD 1). The current configuration includes a static default route ip route 0.0.0.0 0.0.0.0 10.0.0.3, which causes a recursive routing failure because 10.0.0.3 is not a valid next-hop address. Identify and fix the issue, then apply the floating static routes.
⚠ Common exam trap
Be careful: Recursive routing failure means the next-hop is not reachable. Check if the next-hop is directly connected and the interface is up. Do not confuse administrative distance with metric; lower AD is preferred. Also, ensure IPv6 routes use the correct next-hop addresses and AD values.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Remove the existing incorrect IPv4 static default route and reconfigure the primary IPv4 default route with the correct next-hop address (10.0.0.2) and AD 1. Add the backup IPv4 default route via 10.0.0.6 with AD 10. Then add IPv6 static default routes: ipv6 route ::/0 2001:DB8:1:1::2 1 and ipv6 route ::/0 2001:DB8:2:1::2 10. Also add the static route for 192.168.10.0/24 via 10.0.0.2 with AD 1.
The IPv4 default route currently uses next-hop 10.0.0.3, which is not a valid address on any directly connected interface, causing a recursive lookup failure. Option A fixes this by removing the incorrect route and correctly adding the primary (10.0.0.2 with AD 1) and backup (10.0.0.6 with AD 10) default routes, fulfilling the floating static requirement. It also adds both IPv6 floating default routes and the LAN static route. Option B is wrong because adding a route to 10.0.0.0/30 via R3 does not fix the next-hop 10.0.0.3 failure for the default route. Option C incorrectly reverses the administrative distances, making the backup path the primary. Option D erroneously uses an exit interface instead of the correct next-hop IP, which is not suitable for multi-access or point-to-point networks without additional configuration and does not resolve the original misconfigured next-hop.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Remove the existing incorrect IPv4 static default route and reconfigure the primary IPv4 default route with the correct next-hop address (10.0.0.2) and AD 1. Add the backup IPv4 default route via 10.0.0.6 with AD 10. Then add IPv6 static default routes: ipv6 route ::/0 2001:DB8:1:1::2 1 and ipv6 route ::/0 2001:DB8:2:1::2 10. Also add the static route for 192.168.10.0/24 via 10.0.0.2 with AD 1.
Why this is correct
This correctly removes the misconfigured default route (pointing to nonexistent 10.0.0.3), installs the primary default route to R2 with AD 1, adds the backup default route to R3 with AD 10, and completes the floating static setup with IPv6 defaults and the required LAN static route.
- ✗
Add a static route to 10.0.0.0/30 via the backup link to R3, then the default route to 10.0.0.2 will work. Then configure IPv6 default routes with AD 1 and 10 as described.
Why it's wrong here
This is incorrect because adding a static route to 10.0.0.0/30 via the backup link would cause the default route to use the backup path, defeating the purpose of having a primary path. The issue is that the next-hop 10.0.0.2 is not directly connected or reachable; the correct fix is to ensure the interface is up and the next-hop is on a directly connected subnet, not to add a static route via the backup.
- ✗
Change the administrative distance of the IPv4 default route to 10 and the backup to 1, so the backup becomes primary. Then configure IPv6 default routes with AD 10 and 1 respectively.
Why it's wrong here
This is incorrect because it swaps the intended primary and backup paths. The requirement specifies that the primary path goes through R2 with AD 1 and backup through R3 with AD 10. Changing the AD values would make R3 the primary, which is not desired.
- ✗
Remove the existing IPv4 static default route and configure it with the next-hop as the exit interface (e.g., GigabitEthernet0/0) instead of the IP address. Then add IPv6 default routes using the exit interface as well.
Why it's wrong here
This is incorrect because using an exit interface for a static route (point-to-point) is valid, but it does not fix the recursive routing failure if the next-hop IP is unreachable. The issue is likely that the next-hop IP is not in the routing table; using the interface might bypass the recursive lookup but would still require the interface to be up. However, the requirement specifies using next-hop IP addresses, and the IPv6 routes also need next-hop IPs. Moreover, the problem statement indicates the next-hop is 10.0.0.2, which should be directly connected; using the interface is not necessary and may not match the intended design.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓Remove the existing incorrect IPv4 static default route and reconfigure the primary IPv4 default route with the correct next-hop address (10.0.0.2) and AD 1. Add the backup IPv4 default route via 10.0.0.6 with AD 10. Then add IPv6 static default routes: ipv6 route ::/0 2001:DB8:1:1::2 1 and ipv6 route ::/0 2001:DB8:2:1::2 10. Also add the static route for 192.168.10.0/24 via 10.0.0.2 with AD 1.Correct answer▾
Why this is correct
This correctly removes the misconfigured default route (pointing to nonexistent 10.0.0.3), installs the primary default route to R2 with AD 1, adds the backup default route to R3 with AD 10, and completes the floating static setup with IPv6 defaults and the required LAN static route.
✗Add a static route to 10.0.0.0/30 via the backup link to R3, then the default route to 10.0.0.2 will work. Then configure IPv6 default routes with AD 1 and 10 as described.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error: Adding a static route to the next-hop's subnet via a different interface would create a recursive dependency that might not work or would route traffic through the backup link, violating the primary/backup design.
Why candidates choose this
Candidates might think that the recursive routing failure is due to the next-hop not being in the routing table, so they try to add a route to it. However, the next-hop should be directly connected; if it's not, the interface may be down or misconfigured.
✗Change the administrative distance of the IPv4 default route to 10 and the backup to 1, so the backup becomes primary. Then configure IPv6 default routes with AD 10 and 1 respectively.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error: Administrative distance determines route preference; lower AD is preferred. Setting the backup to AD 1 would make it the primary, contradicting the requirement.
Why candidates choose this
Candidates might confuse the concept of floating static routes and think that a higher AD is preferred, or they might incorrectly assume that the backup should have a lower AD to be used when the primary fails.
✗Remove the existing IPv4 static default route and configure it with the next-hop as the exit interface (e.g., GigabitEthernet0/0) instead of the IP address. Then add IPv6 default routes using the exit interface as well.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error: Using an exit interface instead of next-hop IP does not address the root cause of the recursive failure if the interface is up but the next-hop is not reachable due to ARP issues. Also, the IPv6 routes should use next-hop IPs as per the requirement.
Why candidates choose this
Candidates might think that using an exit interface avoids recursive lookups and is simpler, but it is not appropriate for multi-access networks and does not fix the underlying connectivity issue.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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Related to this question
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OSPFv3 Single-Area Configuration for IPv6
Key term
Recursive lookup
A recursive lookup is a query process where a DNS resolver asks multiple DNS servers one after another until it finds the IP address for a domain name, rather than relying on pre-stored information.
Key term
Exit interface
The exit interface is the network interface through which a router forwards a packet out of the router after matching a route in its routing table.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-301 exam.