CCNA IP Routing Practice Test 4 — 15 Questions

Question 1

Match each WAN or interdomain concept to its most accurate description.

Accepted Answer

Autonomous System (AS): A collection of networks under a single administrative domain with a unified routing policy.. The correct description of an Autonomous System (AS) is a collection of IP networks under a single administrative domain with a unified routing policy. Option A accurately reflects this definition. Option B incorrectly describes AS as a routing protocol; that would be BGP, which is used between ASes. Option C confuses AS with MPLS VPN technologies. Option D describes SD-WAN, not AS.

Answer

Autonomous System (AS): A routing protocol used to exchange routes between different administrative domains.

Answer

Autonomous System (AS): A type of VPN that uses MPLS labels to forward traffic across a service provider network.

Answer

Autonomous System (AS): A software-defined approach to managing WAN connections that abstracts underlying hardware.

Question 2

Match each WAN or edge concept to its most accurate description.

Accepted Answer

SD-WAN: A software-defined approach to managing wide-area networks, enabling centralized control and traffic optimization.. The correct match for SD-WAN is the description provided in option A because SD-WAN is indeed a software-defined approach to WAN management that enables centralized control and traffic optimization over multiple connection types. Option B is incorrect because MPLS uses labels to forward packets, but it does not inherently provide encryption; it is a private WAN technology that can be combined with encryption for security. Option C is incorrect because while VPN creates secure encrypted tunnels, it is a specific security technology and not a general WAN or edge concept; the description is too narrow for the broader category of WAN/edge concepts. Option D is incorrect because edge computing processes data near the source, not in a centralized cloud data center; the description given is the opposite of edge computing.

Answer

MPLS: A protocol that uses labels to forward packets, providing secure encrypted tunnels over the internet.

Answer

VPN: A technology that creates a secure, encrypted tunnel over a public network, such as the internet.

Answer

Edge computing: A model where data processing occurs in a centralized cloud data center to reduce latency.

Question 3

Match each troubleshooting command focus to what it most directly helps verify.

Accepted Answer

ping: Network connectivity between hosts. Each command serves a specific verification purpose: ping tests basic IP connectivity between hosts by sending ICMP echo requests and awaiting replies. traceroute maps the path packets take to a destination, displaying each hop and round-trip latency. nslookup queries DNS servers to resolve a hostname to an IP address, verifying name resolution. netstat displays active network connections, listening ports, and protocol statistics, helping identify services and connections.

Question 4

Match each route-selection concept to the description that best fits it.

Accepted Answer

Longest prefix match: Router selects route with the most specific subnet mask. Longest-prefix match selects the most specific matching route. Administrative distance compares trust between route sources. Metric compares candidate paths within a protocol or route source. Default route serves as a fallback when no more specific route exists.

Question 5

A router has two static routes to the same 192.168.1.0/24 network: one via next-hop 10.1.1.1 with metric 10, and the other via next-hop 10.1.1.2 with metric 5. Both routes use the default administrative distance of 1. Which next hop does the router use to forward packets to this destination?

Accepted Answer

10.1.1.2 because it has the lower metric. Both routes have the same prefix length and are static routes. In Cisco IOS, the 'metric' parameter in the 'ip route' command actually sets the administrative distance. The route with the lower administrative distance is preferred. Here, the route via 10.1.1.2 has an administrative distance of 5, which is lower than 10 for the route via 10.1.1.1, so the router selects 10.1.1.2.

Answer

10.1.1.1 because it appears first in the configuration

Answer

Both next hops because all static routes always load balance

Answer

Neither next hop because static routes need tracking to be installed

Question 6

Exhibit: Consider the following ACL applied inbound on interface G0/0:

access-list 100 deny ip host 10.10.10.10 any
access-list 100 deny tcp any host 10.10.10.10 eq 23
access-list 100 permit ip any any

The intent is to block only Telnet (TCP port 23) to server 10.10.10.10 while permitting everything else. However, users cannot reach any service on that server. Why?

Accepted Answer

The deny ip statement blocks all traffic from the host before the Telnet-specific line is evaluated. ACLs are processed top-down, and the first match is applied. The first line denies all IP traffic from the host 10.10.10.10 (source) to any destination. This matches all packets sent by the server, not packets sent to it. As a result, all responses from the server are blocked, which is why users cannot reach any service. To block only Telnet to the server, the ACL should deny tcp any host 10.10.10.10 eq 23, without the broad deny from the host.

Answer

The ACL must be applied outbound, not inbound

Answer

Extended ACLs cannot match TCP port 23

Answer

Telnet uses UDP, so the ACE should reference udp

Question 7

Which IPv4/IPv6 static routing concept is configured by the command `ip route 0.0.0.0 0.0.0.0 serial0/0/0`?

Accepted Answer

Default route. The command `ip route 0.0.0.0 0.0.0.0 serial0/0/0` creates a default static route. A default route matches any destination when no more specific route exists, so it is not a summary, floating, or recursive route. A summary route represents a block of contiguous networks. A floating route is a backup route with a higher administrative distance. A recursive route has a next-hop IP address that requires another route lookup to resolve the exit interface.

Answer

Summary route

Answer

Floating route

Answer

Recursive route

Question 8

Drag and drop the OSPFv2 commands on the left to their correct descriptions on the right.

Accepted Answer

router ospf 1. The 'router ospf 1' command enables the OSPF routing process with process ID 1 on the router. The 'network 10.0.0.0 0.255.255.255 area 0' command specifies that OSPF should be activated on any interface whose IP address falls within the 10.0.0.0/8 range, and it assigns those interfaces to area 0. The 'area 0 stub' command configures area 0 as a stub area, which reduces the size of the link-state database by blocking Type 5 LSAs and requiring a default route. The 'default-information originate' command instructs the router to inject a default route (0.0.0.0/0) into the OSPF domain, typically used on an ASBR.

Answer

network 10.0.0.0 0.255.255.255 area 0

Answer

area 0 stub

Answer

default-information originate

Question 9

Drag and drop the OSPFv3 commands/terms on the left to the correct descriptions on the right.

Accepted Answer

ipv6 ospf 1 area 0: Enables OSPFv3 on an interface in area 0. All four pairings are correct. 'ipv6 ospf 1 area 0' enables OSPFv3 on an interface in area 0, 'router-id' sets the router ID, 'show ipv6 ospf neighbor' displays OSPFv3 neighbor adjacencies, and 'ipv6 router ospf 1' enters OSPFv3 router configuration mode.

Question 10

An engineer is troubleshooting a first-hop redundancy issue on a subnet where two routers, R1 and R2, are configured with HSRP. Hosts on the VLAN are intermittently losing connectivity to the default gateway. The engineer runs the `show standby` command on R1 and sees this output:

```
Vlan1 - Group 10
  State is Active
    2 state changes, last state change 00:00:45
  Virtual IP address is 192.168.1.254
  Active virtual MAC address is 0000.0c07.ac0a
  Local virtual MAC address is 0000.0c07.ac0a (v1 default)
  Hello time 3 sec, hold time 10 sec
  Next hello sent in 1.2 secs
  Preemption enabled
  Active router is local
  Standby router is 192.168.1.1, priority 200 (configured 200)
  Priority 150 (configured 150)
  Group name is "hsrp-Vlan1-10" (default)
```

What is the most likely root cause of the problem?

Accepted Answer

Increase the priority on R1 above 150.. The output shows R1 is in the 'Active' state with priority 150, but the 'Standby' router (R2) has a higher priority of 200. With preemption enabled (as indicated by 'Preempt' in the output), R2 will preempt R1 and become the active router, causing intermittent connectivity as the active gateway flips. Increasing R1's priority above 150 (e.g., to 210) ensures R1 remains the active router, stabilizing the default gateway.

Answer

Change the HSRP group number on R1 to 20.

Answer

Disable preemption on R1.

Answer

Increase the hello timer on R1 to 10 seconds.

Question 11

A network administrator is troubleshooting a connectivity issue on a subnet where two routers, R1 and R2, are configured with HSRP to provide a virtual gateway. Hosts on the subnet can ping the virtual IP address but cannot reach destinations outside the subnet. The administrator discovers that R1 is the active HSRP router. What is the most likely root cause of the problem?

Accepted Answer

Configure a default route on R1 pointing to the next-hop router.. Hosts can successfully ping the HSRP virtual IP address, confirming that HSRP is functioning correctly within the subnet. The inability to reach destinations outside the subnet indicates a lack of routing from the active HSRP router (R1) to external networks. The most likely root cause is that R1 does not have a default route pointing to the next-hop router. Options B, C, and D address HSRP-specific settings (preemption, MAC address, timers) which are irrelevant because the virtual gateway is already reachable; the issue lies in the upstream routing, not in the HSRP configuration.

Answer

Enable preemption on both routers to ensure the higher-priority router stays active.

Answer

Change the virtual MAC address on R2 to match the one on R1.

Answer

Increase the hello timer on R1 to match the hold timer on R2.

Question 12

A network engineer notices that hosts on VLAN 100 (192.168.10.0/24) cannot ping the loopback interface (10.0.0.1/32) of a directly connected router R2. The engineer checks R1's routing table and sees an entry for 10.0.0.0/24 via a different next-hop, but no entry for 10.0.0.1/32. What is the most likely reason for the connectivity failure?

Accepted Answer

R2 is advertising the loopback as a /24 network, not a /32 host route.. The root cause is that R2 is advertising its loopback interface (10.0.0.1/32) as a /24 network (10.0.0.0/24), so R1 never receives the required /32 host route. Because R1 has only the /24 route (which, as stated, points to a different next-hop than R2), it forwards traffic for 10.0.0.1 to that next-hop rather than to R2. The /24 route is not specific enough to match 10.0.0.1 correctly; a /32 route is needed for longest-prefix match to prefer R2. Therefore, the missing /32 advertisement is the most likely reason for the connectivity failure and fixing R2's route advertisement to include a /32 will resolve it.

Answer

The loopback interface on R2 is administratively down.

Answer

R1 has a route for 10.0.0.0/24 via a different next-hop, causing a routing loop.

Answer

The EIGRP metric for the /24 route is too high, so R1 prefers the connected route.

Question 13

Drag and drop the routing concepts on the left to the matching descriptions on the right.

Accepted Answer

Route table: Contains routes that determine network traffic direction. Administrative distance (AD) indicates the trustworthiness of a routing source; OSPF is assigned AD 110. Metric is the cost used by OSPF, calculated based on bandwidth. Longest-prefix match selects the route with the most specific (longest) subnet mask. Directly connected routes have an AD of 0 and are added automatically when an interface IP is configured. Next-hop is the IP address of the next router to forward packets to. Dynamic routes are learned through routing protocols like OSPF or EIGRP.

Question 14

Drag and drop the following steps into the recommended order (best practice) to configure IPv4 and IPv6 static routes, a default route, and a floating static route with higher AD as a backup for the default route, then verify with show ip route and show ipv6 route.

Accepted Answer

Configure IPv4 and IPv6 static routes, then configure a default route, then configure a floating static route with higher AD, then verify with show ip route and show ipv6 route.. The recommended best-practice order is to configure specific static routes first, then the default route, and finally the floating static route with a higher AD (e.g., 200) as a backup. Verification with show ip route and show ipv6 route confirms the routing table. The other sequences are incorrect because they violate the typical progression from specific to general: placing the default route earlier can cause incorrect forwarding, and placing the floating route before the default route undermines the backup logic. Only sequence A follows the correct order.

Answer

Configure a default route, then configure IPv4 and IPv6 static routes, then configure a floating static route with higher AD, then verify with show ip route and show ipv6 route.

Answer

Configure a floating static route with higher AD, then configure IPv4 and IPv6 static routes, then configure a default route, then verify with show ip route and show ipv6 route.

Answer

Configure IPv4 and IPv6 static routes, then configure a floating static route with higher AD, then configure a default route, then verify with show ip route and show ipv6 route.

Question 15

Drag and drop the following OSPFv2 neighbor state transitions into the correct order, starting with the Down state and ending with the ExStart state.

Accepted Answer

Init. OSPF neighbor states progress in order: Down, Init, 2-Way, ExStart, Exchange, Loading, Full. Among the options provided (Down, Init, 2-Way, ExStart), the correct order is Down → Init → 2-Way → ExStart.