Cisco Certified Network Associate (CCNA) 200-301 Practice Test 29
Question 280
A switching team is validating a repair. Earlier, clients authenticate successfully but get DHCP addresses from the guest VLAN instead of the corporate subnet. Which postchange check most directly establishes the specific problem is resolved?
- The client still gets a guest VLAN address but can resolve a public DNS name.
- An authenticated client on the repaired corporate SSID receives an address, gateway and DNS from the intended corporate VLAN, with WLAN mapping and wired tags confirmed.
- The client completes WPA authentication but no WLAN-to-VLAN mapping is inspected.
- Only the AP management IP is in the corporate subnet while station leases remain guest.
Explanation
Correct Answer
B:The prior clients authenticated but leased from guest. Inspect effective policy interface/VLAN and the client’s actual scope/gateway to prove correct segmentation rather than simply any DHCP success.
Incorrect Answers
A:Internet reachability does not prove placement in the required corporate VLAN.
C:Authentication already worked and was not the failed requirement.
D:AP management and user client VLANs are independent in many designs.
Question 281
A router's Gi0/1 interface is configured as 10.28.4.1/24 and reports line protocol up. In `show ip route`, which entry should be expected for the directly connected network, separate from the router's own local /32 entry?
- S 10.28.4.0/24 via 192.0.2.1, created solely by the interface address
- C 10.28.4.0/24 is directly connected, GigabitEthernet0/1
- L 10.28.4.0/24 is directly connected, GigabitEthernet0/1
- O 10.28.4.0/24 via 192.0.2.1, learned automatically without OSPF
Explanation
Correct Answer
B:IOS installs a connected `C` route for the subnet of a routed interface that is administratively and operationally up. The network in this example is 10.28.4.0/24, so that is the connected prefix, with Gi0/1 as the exit interface. IOS also commonly installs a separate local `L` /32 host route for the exact interface address 10.28.4.1. Do not confuse the two entries: the connected route covers other addresses on the subnet, while the local route identifies the router's own address. Verify Gi0/1 has the stated mask and line state before blaming a routing protocol for a missing `C` entry.
Incorrect Answers
A:The `S` route code denotes a static route explicitly configured by an administrator. Simply assigning 10.28.4.1/24 to a functioning routed interface does not require a static `ip route` statement for the connected subnet. A directly connected route is installed automatically when interface conditions are satisfied. A static route with a remote next hop is a different source of reachability.
C:The `L` entry is for a local interface host address and on modern IOS is a /32 for IPv4, not a /24 subnet route. If an interface is 10.28.4.1/24, the expected local entry is 10.28.4.1/32. Calling the entire 10.28.4.0/24 network `L` confuses traffic delivered to the router itself with traffic forwarded over the directly attached link.
D:The `O` route code indicates a route learned through OSPF, which would require the appropriate dynamic routing process and advertisement. The problem provides no OSPF neighbor or LSA. A connected prefix exists due to interface address and state without learning it from a remote OSPF speaker. A remote next-hop address is therefore not the expected source of this directly attached network.
Question 282
A branch routing engineer is evaluating a deployment. An IPv4 router should receive packets addressed to its own Gi0/1 IP 192.0.2.1 via an L 192.0.2.1/32 local host route. What approach correctly addresses the stated requirement?
- `L 192.0.2.1/32 is directly connected, GigabitEthernet0/1` identifies the local interface address that the router processes itself.
- `C 192.0.2.0/24` alone proves packets for 192.0.2.1 must be forwarded to a different neighbor.
- An `O 192.0.2.1/32` OSPF-learned route is necessary before the router can receive packets for its local IP.
- The router must configure a static default route to install its own local /32 entry.
Explanation
Correct Answer
A:IOS installs a local /32 host route for its own up/up numbered IPv4 interface in addition to the connected subnet route. Packets to that exact address terminate at the router rather than being forwarded to the rest of the /24.
Incorrect Answers
B:The /24 is the on-link network; the more-specific L /32 marks the router’s own address.
C:Local interface ownership does not depend on learning an external OSPF route.
D:Local and connected routes arise from operational interface addressing, independent of 0/0.
Question 283
A proposed network design has this requirement: An administrator specifies a static route to a remote LAN using a reachable next hop, and show ip route should mark it S. Which choice is technically appropriate for that deployment?
- A line beginning `C 203.0.113.0/24 is directly connected` indicates a manually learned static remote route.
- A line beginning `O 203.0.113.0/24 [110/...]` denotes a manually configured static route.
- An installed `S 203.0.113.0/24 [1/0] via 192.0.2.2` identifies a manually configured static remote prefix and reachable next hop.
- An `L 203.0.113.1/32` entry identifies a remote static next hop rather than the router’s own address.
Explanation
Correct Answer
C:The routing code S denotes a static route. IOS installs an eligible configured static when its forwarding prerequisites are met; the bracketed pair shows administrative distance and metric.
Incorrect Answers
A:C denotes a connected interface subnet, not a configured static route.
B:O marks a route learned through OSPF, with OSPF’s standard AD shown in the RIB.
D:L is a local host route assigned to the router’s numbered interface.
Question 284
A branch routing engineer must implement a change. Two routers exchange a remote prefix through single-area OSPF and the active route should use code O with appropriate cost. Which technical decision most directly meets these requirements?
- Expect code `S` for the route solely because the OSPF neighbor shares an Ethernet cable.
- The active route to the neighbor-advertised prefix appears as `O` with `[110/<OSPF cost>]` and the OSPF next hop.
- Expect code `L` for every remote OSPF prefix advertised by a neighbor.
- Read the 110 as the destination prefix length and the remaining number as elapsed time.
Explanation
Correct Answer
B:For an intra-area OSPF route, IOS uses code O and displays administrative distance and accumulated cost. The routing table contains an installed best route only after a suitable OSPF adjacency/LSDB and selection process.
Incorrect Answers
A:S denotes static configuration, not dynamic OSPF origin.
C:L marks local interface host addresses, not remote prefixes learned from OSPF.
D:In `[110/cost]`, 110 is the OSPF administrative distance and the second field is route metric.
Question 285
A router chooses paths from destination-prefix matches rather than the packet's source subnet, using longest matching prefix. The team needs a solution consistent with this requirement. Which option is the most appropriate design or configuration decision?
- Always choose the connected prefix matching the packet source IP before examining the destination.
- Prefer the default route over every /24 even when the destination lies inside that /24.
- Choose the route with the lowest administrative distance across unrelated destination prefix lengths before comparing masks.
- Match the packet’s destination IP to routes and forward using the longest matching destination prefix.
Explanation
Correct Answer
D:Routers normally choose the most specific matching destination prefix before considering AD or metric between candidate routes to the same prefix. Source address is generally not the lookup key without an explicit policy-based routing feature.
Incorrect Answers
A:Ordinary destination-based forwarding does not select the egress route from the source prefix.
B:A /24 has more matched leading bits than 0/0 and wins the longest-prefix comparison.
C:Administrative distance decides among competing route sources for the same prefix, not across different longest matches.
Question 286
A branch routing engineer is evaluating a deployment. A routing table entry for 192.0.2.0/25 must cover 192.0.2.0–127, not the whole /24. What approach correctly addresses the stated requirement?
- Treat 192.0.2.200 as inside 192.0.2.0/25 because it shares the first three octets.
- Interpret /25 as a subnet mask of 255.255.0.0 with only the first two octets matched.
- Assume 192.0.2.0/25 denotes only the single IP 192.0.2.0.
- `192.0.2.0/25` covers addresses 192.0.2.0 through 192.0.2.127 (mask 255.255.255.128).
Explanation
Correct Answer
D:The last octet has one network bit for /25, creating blocks of 128 addresses. The next block, 192.0.2.128/25, is a different prefix and is not included in this route.
Incorrect Answers
A:That logic matches a /24, not the given /25 whose upper half starts at .128.
B:255.255.0.0 is /16; /25 includes the high bit in the fourth octet.
C:A /25 represents a 128-address prefix, not one /32 host route.
Question 287
A proposed network design has this requirement: An IP route specifies a next-hop address that must itself resolve to a connected outgoing interface through the RIB/FIB. Which choice is technically appropriate for that deployment?
- Resolve the route’s next-hop IP to an outgoing connected interface and Layer 2 adjacency before attempting final forwarding.
- Send packets directly to any next-hop IP even if no route to it exists in the FIB.
- Use the packet source address as the next-hop interface selector and ignore the RIB.
- Convert an unresolved IPv4 next hop into a local L /32 route automatically.
Explanation
Correct Answer
A:An IP route naming a next-hop must be recursively resolved through a usable route to that next-hop. On Ethernet, the selected adjacent next hop then needs an appropriate neighbor MAC resolution.
Incorrect Answers
B:Without recursion to an outgoing interface, the next hop is not usable for packet forwarding.
C:Normal forwarding follows the route to the destination and its resolved next hop.
D:L routes represent actual router interface addresses; arbitrary next hops do not become local addresses.
Question 288
R1 has two learned routes for exactly 203.0.113.0/24: a static route with administrative distance 1 and an OSPF route with administrative distance 110. Both next hops are reachable. Which route source does R1 install for this prefix under normal Cisco IOS preferences?
- The OSPF route because dynamic protocol routes always override static routes.
- Both routes as equal-cost multipath because they match the same /24 prefix.
- The static route with administrative distance 1, because the two candidates have the same prefix and its administrative distance is lower.
- The route with the newest uptime field, regardless of its administrative distance.
Explanation
Correct Answer
C:When routes from different sources compete for the same destination prefix length, Cisco selects the candidate according to its administrative distance, provided the route is valid and its next hop resolves. The static route's default distance is 1, lower than the typical OSPF distance of 110, so static normally wins. If the static route becomes unusable, a valid dynamic candidate may be installed. Do not confuse this installation decision with packet forwarding across different-length prefixes, where longest-prefix matching is decisive among installed routes. Verify the selected `S` route in `show ip route 203.0.113.0`.
Incorrect Answers
A:Dynamic routes can respond to topology changes, but being dynamic does not automatically give them preference over valid static routes for the same prefix. Administrative distance compares trust between route sources. In this case OSPF's 110 is larger than the static distance 1, so the OSPF candidate normally loses installation preference.
B:Equal-cost multipath requires compatible eligible routes, usually with appropriate matching source and metric conditions. Two candidates from different protocols with administrative distances 1 and 110 are not considered equivalent simply because their /24 destination matches. The lower-distance static route is selected instead of both independently entering a multipath set.
D:The age or uptime shown beside a route may help troubleshooting when information was learned or last changed. It is not the normal priority selector between a valid static and OSPF route of the identical prefix. The administrative distance differentiates their source preference; the newer timestamp alone does not override that.
Question 289
Two candidate routes to the same prefix are learned via the SAME protocol, and the protocol-specific metric ranks their costs. The team needs a solution consistent with this requirement. Which option is the most appropriate design or configuration decision?
- Treat a larger OSPF accumulated cost as always more preferred because it indicates more hops.
- Compare the routing-table elapsed-time field as if it were the OSPF metric.
- For routes to the exact same prefix learned through the same protocol, prefer that protocol’s lower metric after confirming candidate viability.
- Select a default 0/0 route rather than the exact matching learned prefix solely because the default has AD 1.
Explanation
Correct Answer
C:Intra-protocol selection uses a protocol-specific metric, such as OSPF cost. AD is chiefly used to compare routes from different administrative sources for the same destination prefix.
Incorrect Answers
A:OSPF ordinarily selects the minimum total path cost, not the maximum.
B:Elapsed time records update age; the second bracket field `[AD/metric]` is the reported metric.
D:A more-specific installed prefix takes precedence over a default route for that destination.
Question 290
A branch router has installed connected 10.8.0.0/24, static 172.16.8.0/24, and OSPF 192.168.20.0/24 routes. Host 198.51.100.80 matches none of them. Which additional route would allow the router to select an upstream next hop for such otherwise unmatched IPv4 destinations?
- An installed 0.0.0.0/0 default route with a reachable upstream next hop.
- An added local 10.8.0.1/32 route for the branch router's own interface.
- A static 172.16.8.0/24 route with an even lower administrative distance.
- A route to 192.168.20.0/25 learned through OSPF.
Explanation
Correct Answer
A:A default route has prefix length zero, so it matches destinations when no longer-prefix entry matches. An installed 0.0.0.0/0 route with a valid next hop provides the branch router's gateway of last resort for 198.51.100.80 and other unmatched destinations. The router still needs a resolved next hop and working upstream forwarding, so merely entering a command does not guarantee Internet reachability. Verify `show ip route 0.0.0.0` and test the next hop before claiming full service. Specific connected, static or OSPF routes take priority for destinations they cover because they are longer matches; the default does not replace those entries. This is the defining role of gateway of last resort in IPv4 routing.
Incorrect Answers
B:A local /32 identifies a particular IP address assigned to the router itself. It does not supply a path to arbitrary remote destinations such as 198.51.100.80. Even though a local host route is a very specific entry, it does not match an unrelated address. A route must contain the destination to be eligible for forwarding selection, so adding another local address record is irrelevant.
C:Administrative distance influences which competing route source is installed for the same prefix, but it does not expand a 172.16.8.0/24 route to cover 198.51.100.80. That address lies in a different network. Reducing the distance of a nonmatching route cannot make it a gateway of last resort. Prefix membership is the first question to ask.
D:A /25 route within 192.168.20.0/24 describes an even narrower destination subset of that already installed network. It matches only addresses in the covered half of 192.168.20.x and cannot provide a path for 198.51.100.80. Changing routing protocol does not alter the destination network described by the prefix. The unmatched host needs a default or other matching route.
