CCNA IP Routing Practice Test 22 — 15 Questions

Question 1

You are troubleshooting connectivity from R1 to the 172.16.20.0/24 network. The network engineer configured a floating static route on R1 as a backup for the OSPF-learned route, but after the primary OSPF route fails, the backup does not take over. Examine the current routing table and partial configuration on R1, then fix the issue so that when the OSPF neighbor goes down, R1 can still reach 172.16.20.0/24 via R3.

Accepted Answer

Change the static route to use an exit interface: ip route 172.16.20.0 255.255.255.0 GigabitEthernet0/1 203.0.113.2. The floating static route was configured with an administrative distance of 130, intended to be higher than OSPF's default AD of 110 so it would only be used as a backup. However, the static route's AD is set as 130 (the command uses the distance option), which is correct. The problem is that OSPF's AD is 110, which is lower, so the static route is not installed while OSPF is up. But when OSPF fails, the static route should appear. The issue is that the static route is pointing to a next-hop (203.0.113.2) that is not directly connected; R1 has no route to 203.0.113.2, causing the static route to be inactive. To fix, you must either change the next-hop to a directly connected interface (e.g., GigabitEthernet0/1) or add a route to reach 203.0.113.2. The simplest solution is to configure the static route with an exit interface: 'ip route 172.16.20.0 255.255.255.0 GigabitEthernet0/1 203.0.113.2'. This ensures the route is valid when the OSPF route disappears.

Answer

Change the administrative distance of the static route to 110

Answer

Remove the OSPF process from R1

Answer

Add a static route to 203.0.113.0/24 via R1's directly connected interface

Question 2

You are connected to R1 via console. R1 has two upstream paths to the Internet: a primary via ISP1 (G0/0 10.1.1.1/30) and a backup via ISP2 (G0/1 10.2.2.1/30). The backup path should only be used when the primary fails. The default route to ISP1 has been configured, but you must now configure a floating static default route to ISP2 with an administrative distance of 200.

Accepted Answer

ip route 0.0.0.0 0.0.0.0 10.2.2.2 200. A floating static route ensures backup connectivity by using an administrative distance (AD) higher than the primary route's AD. Here, the primary default route has an AD of 1, so the backup must be configured with AD 200 as specified. Crucially, the next-hop address must be the ISP's IP address (10.2.2.2) in the /30 subnet, not R1's own interface IP (10.2.2.1). Using the local interface IP creates an invalid static route. Option A is correct only with the next-hop set to 10.2.2.2. Options B and C fail because they use AD 2 and 1 respectively (not the required 200) and also point to the wrong next-hop. Option D uses AD 250 instead of 200 and has the same next-hop error.

Answer

ip route 0.0.0.0 0.0.0.0 10.2.2.1 2

Answer

ip route 0.0.0.0 0.0.0.0 10.2.2.1 1

Answer

ip route 0.0.0.0 0.0.0.0 10.2.2.1 250

Question 3

You are connected to R1 via console. R1 is connected to three routers (R2, R3, R4) over Ethernet links, all in OSPF area 0. Due to network topology, R1 should not become the Designated Router (DR) or Backup Designated Router (BDR) on any of its interfaces. You need to configure R1's OSPF priority appropriately to ensure it never participates in DR/BDR elections.

Accepted Answer

Set the OSPF priority to 0 on all interfaces of R1.. Setting the OSPF priority to 0 on each Ethernet interface excludes R1 from DR/BDR elections entirely, as a priority of 0 signals that the router is ineligible. In contrast, option B (priority 255) is incorrect because the highest priority makes a router the most likely to become DR/BDR, not prevent it. Option C (priority 1) allows the router to participate in elections and could still become DR/BDR if no higher-priority router exists. Option D is wrong because setting priority to 0 on the loopback interface does not affect the physical Ethernet interfaces where elections occur.

Answer

Set the OSPF priority to 255 on all interfaces of R1.

Answer

Set the OSPF priority to 1 on all interfaces of R1.

Answer

Set the OSPF priority to 0 on the loopback interface of R1.

Question 4

You are connected to R1 via console. R1 and R2 are configured with EIGRP AS 100. R1's loopback0 (1.1.1.1/32) should be advertised into EIGRP. However, after configuration, R2 does not have a route to 1.1.1.1/32. You need to verify the EIGRP configuration on R1 and R2 to determine why the route is missing. Use show commands to identify the issue.

Accepted Answer

Use 'show ip eigrp interfaces' on R1 to verify that EIGRP is enabled on the interface facing R2 and that it is not passive.. The root cause is that R1's interface facing R2 is passive, preventing EIGRP neighbor adjacency. 'show ip eigrp interfaces' verifies the passive state, identifying why no routes are exchanged. Option B is incorrect because the local topology table may contain the route, but without an active neighbor, it will not be advertised; the topology check alone is insufficient. Option C is incorrect because the routing table may also show the locally connected route, but that does not explain why R2 lacks it. Option D is incorrect because checking R2's EIGRP configuration does not reveal R1's passive interface, which is the actual problem.

Answer

Use 'show ip eigrp topology' on R1 to confirm that the 1.1.1.1/32 route is in the EIGRP topology table.

Answer

Use 'show ip route eigrp' on R1 to verify that the 1.1.1.1/32 route is in the routing table.

Answer

Use 'show ip protocols' on R2 to verify that EIGRP AS 100 is configured and that the network statement includes the subnet of the interface facing R1.

Question 5

You are connected to R1 via console. R1 is a new router connecting two subnets: 192.168.1.0/24 on G0/0 and 192.168.2.0/24 on G0/1. You need to configure IPv6 static routes so that hosts on these subnets can reach the IPv6 Internet via R2 (2001:db8:1::2). R1's G0/0 has IPv6 address 2001:db8:1::1/64, and R2 is the next-hop. Also configure a default IPv6 route toward R2.

Accepted Answer

ipv6 route ::/0 2001:db8:1::2. A default IPv6 static route with prefix ::/0 points to the next-hop 2001:db8:1::2, which correctly forwards all traffic not in the local routing table to R2 for Internet reachability. Option B is wrong because it creates a static route for the directly connected network 2001:db8:1::/64, which is already in the routing table and unnecessary. Option C fails because on Ethernet interfaces, a static route must specify a next-hop IP address, not just an exit interface. Option D is incorrect because it creates a host route to 2001:db8:1::2, which is a directly connected address, and does not provide a default route.

Answer

ipv6 route 2001:db8:1::/64 2001:db8:1::2

Answer

ipv6 route ::/0 g0/0

Answer

ipv6 route 2001:db8:1::2/128 g0/0

Question 6

You are connected to R1 via the console. R1 is a newly deployed router that connects two subnets: 192.168.1.0/24 on GigabitEthernet0/0 and 192.168.2.0/24 on GigabitEthernet0/1. There is a default route to the Internet via ISP router at 203.0.113.1, but the network policy requires that traffic from 192.168.1.0/24 to the Internet must exit via a different next-hop 203.0.113.2. You need to implement policy-based routing on R1 to forward traffic from source 192.168.1.0/24 to 203.0.113.2, while all other traffic uses the default route via 203.0.113.1.

Accepted Answer

Create an access list matching source 192.168.1.0/24, a route-map with set ip next-hop 203.0.113.2, and apply the route-map inbound on GigabitEthernet0/0.. Policy-based routing (PBR) allows overriding the routing table for specific traffic. The access list identifies traffic from 192.168.1.0/24, the route-map sets the next-hop to 203.0.113.2, and applying it to the incoming interface G0/0 ensures that traffic entering from that subnet follows the policy.

Answer

Create an access list matching source 192.168.1.0/24, a route-map with set ip next-hop 203.0.113.2, and apply the route-map outbound on GigabitEthernet0/1.

Answer

Create an access list matching destination 203.0.113.2, a route-map with set ip next-hop 203.0.113.2, and apply the route-map inbound on GigabitEthernet0/0.

Answer

Configure a static route for 192.168.1.0/24 with next-hop 203.0.113.2 and rely on the default route for other traffic.

Question 7

You are connected to R1 via console. R1 connects three subnets: 10.0.1.0/24 (area 0), 10.0.2.0/24 (area 0), and 10.0.3.0/24 (area 0). The serial link to R2 uses IP subnet 10.0.0.0/30 and is in OSPF area 1. The network administrator wants to advertise a single summary route for these three subnets to R2, reducing the OSPF link-state database size in area 1. R1 is already running OSPF with network statements for its connected subnets in their respective areas. You need to configure route summarization on R1 so that only the summary route is advertised to R2 via the serial link.

Accepted Answer

router ospf 1
 area 0 range 10.0.0.0 255.255.252.0. The 'area 0 range' command creates a summary route for the specified range, which is then advertised as a type 3 summary LSA to other areas. This reduces routing table size and prevents flapping.

Answer

router ospf 1
 summary-address 10.0.0.0 255.255.252.0

Answer

interface serial 0/0/0
 ip summary-address ospf 1 10.0.0.0 255.255.252.0

Answer

router ospf 1
 area 0 range 10.0.0.0 255.255.255.0

Question 8

You are connected to R1 via console. R1 is a router that has two paths to the Internet: one via ISP1 with next-hop 203.0.113.1, and a backup via ISP2 with next-hop 203.0.113.2. The primary path should be via ISP1, but if it fails, traffic should automatically use ISP2. Currently, R1 has a static default route to ISP1 only. You need to configure a floating static route to ISP2 with an administrative distance of 150 to provide backup connectivity. Additionally, you must ensure that the backup route is only used when the primary route is not available.

Accepted Answer

ip route 0.0.0.0 0.0.0.0 203.0.113.2 150. By setting the administrative distance to 150, the backup static route is less preferred than the primary static route (distance 1). If the primary route is removed due to a failure, the floating route is installed, providing backup connectivity.

Answer

ip route 0.0.0.0 0.0.0.0 203.0.113.2 1

Answer

ip route 0.0.0.0 0.0.0.0 203.0.113.2 250

Answer

ip route 0.0.0.0 0.0.0.0 203.0.113.2

Question 9

You are connected to R1 via console. R1 is connected to R2 via GigabitEthernet0/0 (10.0.0.1/30) and to R3 via GigabitEthernet0/1 (10.0.0.5/30). R1 has a management subnet 192.168.1.0/24 connected to GigabitEthernet0/2. The network administrator wants to ensure that traffic from the management subnet to the Internet (203.0.113.0/24) uses R2 as the primary path and R3 as a backup. Currently, OSPF is running with default metrics. You must configure a floating static route that will be used only if the OSPF route fails.

Accepted Answer

ip route 203.0.113.0 255.255.255.0 10.0.0.6 150. The floating static route is configured with an administrative distance of 150, which is higher than OSPF's default AD of 110. This ensures that the static route is only installed in the routing table when the OSPF route is not present (e.g., due to a failure). The next-hop is R3's IP on the directly connected link.

Answer

ip route 203.0.113.0 255.255.255.0 10.0.0.2 150

Answer

ip route 203.0.113.0 255.255.255.0 10.0.0.6 110

Answer

ip route 0.0.0.0 0.0.0.0 10.0.0.6 150

Question 10

You are connected to R1 via console. R1 has three directly connected subnets: 192.168.1.0/24 (G0/0), 192.168.2.0/24 (G0/1), and 192.168.3.0/24 (G0/2). You need to configure a summary route to be advertised to a neighbor via a static route pointing to Null0 to prevent routing loops. The summary should cover all three subnets.

Accepted Answer

ip route 192.168.0.0 255.255.252.0 Null0. The three subnets 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24 can be summarized as 192.168.0.0/22, which covers 192.168.0.0 to 192.168.3.255. A static route to Null0 ensures that traffic matching the summary but not a more specific route is dropped, preventing routing loops.

Answer

ip route 192.168.1.0 255.255.252.0 Null0

Answer

ip route 192.168.0.0 255.255.255.0 Null0

Answer

ip route 192.168.0.0 255.255.254.0 Null0

Question 11

You are connected to R1 via console. R1 and R2 are connected via two serial links: Serial0/0/0 (10.0.0.1/30) and Serial0/0/1 (10.0.0.5/30). OSPF is configured on both links. However, the OSPF neighbor adjacency is stuck in EXSTART/EXCHANGE state. You suspect a mismatch in OSPF parameters. You need to identify and fix the issue.

Accepted Answer

Check and adjust the MTU on the serial interfaces to match.. The adjacency stuck in EXSTART/EXCHANGE is often due to an MTU mismatch. If one interface has a lower MTU, the DBD packets may be fragmented or rejected, preventing the exchange of LSAs. Setting the same MTU on both sides resolves the issue.

Answer

Check and adjust the OSPF hello and dead timers to match.

Answer

Check and adjust the OSPF network type on the interfaces to match.

Answer

Check and adjust the OSPF area ID on the interfaces to match.

Question 12

You are connected to R1 via console. R1 is connected to R2 via GigabitEthernet0/0 and to R3 via GigabitEthernet0/1. OSPF has been configured, but R1 is not forming a full adjacency with R2. You run `show ip ospf neighbor` on R1 and see R2 stuck in EXSTART state. You also run `show ip ospf interface GigabitEthernet0/0` and see the network type is broadcast. You need to identify and resolve the issue.

Accepted Answer

Change the OSPF network type on R1's GigabitEthernet0/0 interface to point-to-point.. R1's Gi0/0 defaults to OSPF broadcast network type, while R2 is likely configured as point-to-point. This mismatch prevents the routers from forming a full adjacency, often leaving them stuck in EXSTART or 2-WAY state. Changing R1's interface to point-to-point aligns the network types, allowing adjacency to form. The other options are incorrect because hello interval mismatches (B) or DR priority (C) are not the root cause, and adding the broadcast command (D) would not fix a point-to-point mismatch.

Answer

Increase the OSPF hello interval on R1's GigabitEthernet0/0 interface to match R2's hello interval.

Answer

Configure the OSPF priority on R1's GigabitEthernet0/0 interface to 0 to prevent it from becoming the DR.

Answer

Add the 'ip ospf network broadcast' command on R1's GigabitEthernet0/0 interface.

Question 13

You are connected to R1 via console. R1 has two paths to the Internet: primary via ISP1 (G0/0) and backup via ISP2 (G0/1). The primary route has an administrative distance of 1, and the backup should only be used if the primary fails. Currently, both routes are active. You need to configure a floating static route for the backup.

Accepted Answer

ip route 0.0.0.0 0.0.0.0 G0/1 200. A floating static route with a higher administrative distance (200) than the primary route (1) ensures it is only used when the primary route is removed from the routing table, providing redundancy.

Answer

ip route 0.0.0.0 0.0.0.0 G0/1 1

Answer

ip route 0.0.0.0 0.0.0.0 G0/1 0

Answer

ip route 0.0.0.0 0.0.0.0 G0/1 255

Question 14

You are connected to R1 via console. R1 and R2 are connected via a serial link. OSPFv2 has been configured, but the adjacency is stuck in EXSTART state. You suspect a mismatched MTU. On R1, the interface MTU is currently set to 1400, while R2 uses the default MTU of 1500. You need to verify and fix the issue.

Accepted Answer

On R1, configure the interface MTU to 1500 and then clear the OSPF process using 'clear ip ospf process'.. OSPF requires matching MTU values on a link. The incorrect MTU on R1 (1400) caused the adjacency to stall in EXSTART. Setting MTU to 1500 and clearing the OSPF process allows proper adjacency formation.

Answer

On R1, configure the interface MTU to 1500 and then reload the router to apply the change.

Answer

On R1, configure the interface MTU to 1500 and then change the OSPF network type to point-to-point.

Answer

On R1, configure the interface MTU to 1500 and then adjust the OSPF hello and dead timers to match R2.

Question 15

You are connected to R1 via the console. R1 is a new router that connects to three subnets: 192.168.1.0/24 (connected to GigabitEthernet0/0), 192.168.2.0/24 (connected to GigabitEthernet0/1), and 192.168.3.0/24 (connected to GigabitEthernet0/2). R1 must be able to ping the loopback0 interface of R2 (192.168.100.1/32) which is reachable via R2's Serial0/0/0 interface (10.0.0.2/30). The link between R1 and R2 is 10.0.0.0/30, with R1's interface being 10.0.0.1/30. No dynamic routing protocols are configured. Configure R1 to reach the loopback address of R2 using a host-specific static route (not a default route).

Accepted Answer

ip route 192.168.100.1 255.255.255.255 10.0.0.2. It configures a host route (mask /32) to destination 192.168.100.1 with next-hop 10.0.0.2, directly matching the loopback address and providing exact reachability. Option B is incorrect because it uses a /24 mask, which does not match the /32 loopback and would cause routing issues. Option C is incorrect because it uses next-hop 192.168.1.1, which is not the directly connected neighbor; packets would be forwarded to a local interface, not across the serial link. Option D is incorrect because it creates a default route (0.0.0.0/0) rather than the required host-specific route, failing to meet the specific task requirement.

Answer

ip route 192.168.100.0 255.255.255.0 10.0.0.2

Answer

ip route 192.168.100.1 255.255.255.255 192.168.1.1

Answer

ip route 0.0.0.0 0.0.0.0 10.0.0.2

CCNA IP Routing Practice Test 22 — 15 Questions

Exhibit

CCNA IP Routing Practice Test 22 — 15 Questions

Exhibit