CCNA Show IP Route Questions

The question says R3 advertises the network via OSPF; a missing network command would contradict that, so the failure must be in adjacency formation.

The presence of other OSPF routes on the same interface disproves a blanket multicast ACL; the issue is specific to R3’s adjacency.

A duplicate router ID could prevent adjacency, but the scenario’s focus on passive-interface default provides a more common and direct cause for a total lack of adjacency when OSPF is correctly configured on the network.

Candidates may misinterpret a failed ping as indicating no default route exists, overlooking that the route is present but unusable.

Candidates may think a higher AD is blocking the route, but the AD is standard and not the issue.

A common troubleshooting step is to verify ip routing, but the exhibit clearly shows an active routing table.

The specific factual error: The incorrect static route remains in the routing table, causing recursive routing failure. The router will still try to resolve the next-hop 10.0.0.1, which is its own interface, leading to a loop.

The specific factual error: The route does not have an administrative distance of 10, and using an exit interface instead of a next-hop IP is not the intended configuration. Also, the route would be installed with default AD 1, not 10.

The specific factual error is using an incorrect subnet mask and omitting the next-hop IP in the directly connected static route. The mask should match the point-to-point link (typically /30 or /31), and the next-hop must be specified to ensure the route is directly connected.

The specific factual error is using a /32 mask instead of the subnet mask of the link. A /32 route to the next-hop IP is a valid workaround but is not the standard practice; the question expects a directly connected route to the network containing the next-hop, not a host route.

The specific factual error is using the floating route's next-hop as the next-hop for the directly connected route. The directly connected route must be to the network containing 192.0.2.2, not to the backup next-hop.

This option is wrong because the OSPF route to 10.60.4.0/24 does not directly match the destination 10.60.4.17, which falls under the static route to 10.60.4.16/28. OSPF would not be preferred if a more specific static route exists.

The EIGRP route to 10.60.0.0/16 is not used for the destination 10.60.4.17 because it does not match the more specific subnet of 10.60.4.16/28, which is preferred in routing decisions.

This option is wrong because there is a valid static route to the destination 10.60.4.17 via the static route to 10.60.4.16/28, making it reachable. Therefore, stating 'no route at all' is incorrect in this context.

Setting the floating route AD to 1 makes it equal to the primary route's AD, defeating the purpose of a floating static route.

The primary route must have a lower AD than the floating route to be preferred. Setting it to 200 makes it equal to the backup, causing ambiguity.

The question states 'IPv4 and IPv6 static routes, default routes' and specifies an IPv6 next-hop. Ignoring IPv6 is a direct violation of the requirements.

Candidates often assume that a route pointing to an interface requires that interface to be up, but Null0 is always available.

A misconception that the default route is special and cannot be used with Null0, but any valid IP prefix can be directed to Null0 to create a discard route.

Confusing Null0 routes with Ethernet interface routes, which require a next hop, leads to the incorrect belief that a next hop is mandatory for all static routes.

Swapping the ADs would keep the backup route preferred, failing to make the primary path active when available.

The OSPF route to 10.30.5.0/24 is less specific than the /25 static route, so the router prefers the longest mask.

The default route (0.0.0.0/0) has the shortest prefix length and would be used only if no other route matches.

10.30.5.130 is inside the 10.30.5.128/25 subnet range, meaning a route exists for this destination.

Incorrect. A high administrative distance does not make a route override dynamic routes; it makes the route less preferred. Therefore, the static route will not immediately override dynamic routes.

Incorrect. Assigning a high administrative distance does not disable the route; it remains configured and available as a backup. The route is not conceptually disabled but deprioritized.

Incorrect. Administrative distance affects route preference, not the route prefix or mask. Changing AD does not convert a default route into a host route.

This option is incorrect because static routes do not always win over dynamic routes; the route with the lowest administrative distance is preferred. In this case, OSPF has a lower administrative distance (110) than the floating static route (130).

This option is incorrect because only one route can be installed in the routing table for a specific prefix, and in this case, OSPF has a lower administrative distance than the floating static route, so only the OSPF route will be installed.

This option is incorrect because OSPF is healthy and has a lower administrative distance than the floating static route, meaning the OSPF route will be preferred and installed in the routing table.

192.168.40.0/24 is a valid route but less specific than 192.168.40.128/25. Since the destination IP falls within both, the router prefers the more specific /25 route, so this option is incorrect.

0.0.0.0/0 is the default route and only used when no other route matches. Since more specific routes exist for the destination IP, this option is incorrect.

Overlapping routes like /24 and /25 are common and resolved by longest prefix match. The presence of overlapping entries does not prevent route selection, so this option is incorrect.

Candidates mistakenly assume that OSPF process IDs must match globally for proper LSA exchange, but they are only locally significant.

Candidates may think that the network type influences the OSPF LSA type, but it only affects neighbor discovery and DR/BDR election, not the area origin of LSAs.

Candidates sometimes confuse the metric influence with the route type, thinking that OSPF converts routes when the cost exceeds a threshold.

Uses AD 2 instead of the specified AD 200 and a wrong next-hop of 10.2.2.1.

Uses AD 1 (equal to the primary route's AD), preventing failover, and a wrong next-hop of 10.2.2.1.

Uses AD 250 instead of the required AD 200 as specified in the question, and still uses the wrong next-hop.

Incorrect because static routes can reference exit interfaces directly; Cisco routers support static routes with either next-hop IP addresses or exit interfaces.

Incorrect because the subnet mask length (such as /16 vs /24) does not prevent a static route from being installed; the issue is the interface state, not the mask.

Incorrect because static routes do not depend on NTP or time synchronization for installation; this is unrelated to static routing behavior.

A lower AD indicates a more trustworthy source, so the route with the lower AD is preferred, not the higher one.

Metrics are only comparable within the same routing protocol (e.g., OSPF cost vs. EIGRP composite metric). For different protocols, AD is used to select the best route.

A lower AD is preferred; OSPF AD 110 is lower than 200, so the OSPF route would be chosen.