CCNA Network Infrastructure and Connectivity Practice Test 22 — 15 Questions

Question 1

Drag and drop the following troubleshooting steps into the correct order to diagnose a client connectivity issue using the OSI bottom-up method. The client cannot access a web server by its FQDN.

Accepted Answer

Check physical connectivity (cables, link lights, interface status).. The bottom-up OSI troubleshooting approach starts at Layer 1 (physical) and moves upward. For this scenario (client cannot access web server by FQDN), the correct order is: first check physical connectivity (Layer 1), then check data link layer (Layer 2) for MAC and VLAN issues, then check network layer (Layer 3) for IP configuration, and finally check application layer (Layer 7) for DNS resolution. This systematic approach ensures lower-layer issues are ruled out before investigating higher-layer problems.

Question 2

You are connected to R1. The link between R1 and R2 is experiencing intermittent connectivity and poor performance. Review the provided show interface output to identify the root cause(s) of the issue, then apply the necessary configuration changes to resolve the problem and restore full connectivity.

Output from R1:
```
GigabitEthernet0/0 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is aaaa.bbbb.cccc (bia aaaa.bbbb.cccc)
  Internet address is 192.168.1.1/30
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 100Mb/s, link type is auto, media type is RJ45
  output flow-control is unsupported, input flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:01, output 00:00:01, output hang never
  Last clearing of "show interface" counters 00:01:23
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     150 packets input, 1500 bytes, 0 no buffer
     Received 0 broadcasts (0 multicasts)
     0 runts, 0 giants, 0 throttles
     150 input errors, 150 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     200 packets output, 2000 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out
```

Accepted Answer

Configure the interface with 'speed 1000' and 'duplex full' to match R2's settings, then clear counters.. The show interface output reveals that R1's GigabitEthernet0/0 is operating at half-duplex, 100 Mb/s, yet it is accumulating a high number of CRC errors (150 in 1 minute 23 seconds). This indicates a speed/duplex mismatch with R2, which is likely set to full-duplex at 1000 Mb/s. To resolve, you must manually configure R1 to match R2's proper settings by issuing the 'speed 1000' and 'duplex full' commands, then clearing the counters to start fresh monitoring. The other options are incorrect because they do not address the mismatch: replacing the cable would not fix a configuration issue; disabling autonegotiation alone may not fix the mismatch if the hard-coded values are still wrong; and increasing the MTU does not affect CRC errors caused by duplex mismatch.

Answer

Replace the faulty cable between R1 and R2 to eliminate CRC errors caused by physical layer issues.

Answer

Disable autonegotiation on the interface with 'no negotiation auto' to force the link to use the configured speed and duplex.

Answer

Increase the interface MTU to reduce fragmentation and improve performance on the link.

Question 3

You are connected to R1. The link between R1 and R2 is experiencing packet loss and slow performance. Examine the following partial show interface output:

R1# show interfaces gigabitEthernet 0/0
GigabitEthernet0/0 is up, line protocol is up
  Duplex: Full, Speed: Auto, 100Mb/s
  Input errors: 12345, CRC: 5000, frame: 0, overrun: 0, ignored: 0

R2# show interfaces gigabitEthernet 0/0
GigabitEthernet0/0 is up, line protocol is up
  Duplex: Half, Speed: Auto, 100Mb/s
  Input errors: 0, CRC: 0, collisions: 5000, late collisions: 0

Identify the root cause of the issue, and apply the necessary fix on R1 to resolve the problem.

Accepted Answer

Configure the interface with 'duplex half' to match the half-duplex setting on R2.. The output reveals a duplex mismatch. R1 is operating in full‑duplex mode, while R2 is in half‑duplex mode. On the full‑duplex side (R1), simultaneous transmissions from both ends result in corrupted frames, visible as a high count of CRC errors. On the half‑duplex side (R2), ordinary collisions occur because R2 uses CSMA/CD, but no CRC errors are seen because it detects collisions and retransmits. The only immediate fix from R1—since R2 is fixed at half‑duplex—is to change R1's interface to half‑duplex using the command 'duplex half', which matches the settings and stops the corrupted frames. (Long‑term, both sides should ideally be set to full‑duplex, but that requires access to R2.)

Answer

Configure the interface with 'speed 100' to force the link speed to 100 Mbps.

Answer

Replace the Ethernet cable with a new one to fix the physical layer issue.

Answer

Configure the interface with 'no shutdown' to bring the interface up.

Question 4

You are troubleshooting connectivity between R1 and R2. The link is down, and you need to identify and fix the issue. Examine the provided 'show interfaces' output and running configuration, then apply the necessary commands to restore connectivity.

Accepted Answer

Enter interface configuration mode for the down interface and issue the 'no shutdown' command.. The interface is administratively down because the 'shutdown' command is present. The line protocol is down because the interface is disabled. To fix this, you must issue the 'no shutdown' command on the interface. After that, the interface will come up, and the line protocol will become up if the other side is properly configured.

Answer

Enter global configuration mode and issue the 'interface reset' command to reset the interface counters.

Answer

Enter interface configuration mode and issue the 'speed' command to set the interface speed to match the connected device.

Answer

Enter interface configuration mode and issue the 'no keepalive' command to disable keepalives.

Question 5

You are connected to R1. The link between R1 and R2 is down. The output of 'show interfaces gigabitEthernet0/0' on R1 shows: 'GigabitEthernet0/0 is administratively down, line protocol is down (disabled)', with IP address 203.0.113.1/30, MTU 1500, and no input/output errors. Determine the root cause and configure the necessary fix to bring the interface up and restore connectivity.

Accepted Answer

Enter interface configuration mode for GigabitEthernet0/0 and issue the 'no shutdown' command.. The interface status 'administratively down' means the interface was manually shut down using the 'shutdown' command. To bring it up, you must enter interface configuration mode and issue 'no shutdown', which administratively enables the interface. The other options are incorrect: setting speed to 100 Mbps or forcing full-duplex will not fix an administratively down state, and disabling keepalives is unrelated to the interface being disabled.

Answer

Enter interface configuration mode and issue the 'speed 100' command to match the remote interface speed.

Answer

Enter interface configuration mode and issue the 'duplex full' command to force full-duplex operation.

Answer

Enter interface configuration mode and issue the 'no keepalive' command to disable keepalives.

Question 6

You are connected to R1. The network administrator reports that hosts on VLAN 10 cannot communicate with the server attached to R2's GigabitEthernet0/1 interface. Troubleshoot and resolve the issue. Identify the root cause and apply the necessary fix on R1.

Accepted Answer

Configure 'no duplex' and 'no speed' under interface GigabitEthernet0/0 to enable auto-negotiation.. The issue is a duplex mismatch on GigabitEthernet0/0. R1 is configured with 'duplex full' and 'speed 1000', but the connected switch port is likely set to auto-negotiate or is set to half-duplex. This causes high input errors (1500) and degraded performance. The fix is to set R1's G0/0 to auto-negotiate both speed and duplex, matching the switch's configuration. Enter interface configuration mode for G0/0, issue 'no duplex' and 'no speed' to revert to auto, then clear the interface counters with 'clear counters gigabitethernet0/0'.

Answer

Change the duplex setting on GigabitEthernet0/0 to half-duplex using 'duplex half'.

Answer

Apply 'speed 100' and 'duplex full' on GigabitEthernet0/0 to match a common switch configuration.

Answer

Clear the interface counters on GigabitEthernet0/0 with 'clear counters gigabitethernet0/0' without changing any configuration.

Question 7

You are connected to R1. The network team reports intermittent connectivity between R1 and R2. Examine the following `show interface` output from R1 to identify the root cause of the issue. Then apply the necessary configuration commands on R1 to resolve the problem.

GigabitEthernet0/0 is up, line protocol is up
  Internet address is 10.0.0.1/30
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is RJ45
  output flow-control is unsupported, input flow-control is unsupported
  Last input 00:00:01, output 00:00:01, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     100 packets input, 8000 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     100 input errors, 100 CRC, 0 frame, 0 overrun, 0 ignored
     0 output errors, 0 collisions, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out

Accepted Answer

Enter interface configuration mode for the problematic interface and issue the 'no speed' and 'no duplex' commands to revert to auto-negotiation.. The show interface output reveals 100 CRC errors and 100 input errors, indicating a physical layer problem. Additionally, the interface is manually configured for full-duplex and 100 Mb/s. CRC errors often point to a duplex mismatch or faulty cable. Since R1 is set to full-duplex, if R2 is set to auto-negotiation (or half-duplex), a mismatch occurs. The fix is to set both sides to auto-negotiation by removing manual speed and duplex settings. On R1, enter interface configuration mode and issue 'no speed' and 'no duplex' to revert to auto-negotiation, then verify with 'show interfaces' that the interface negotiates to full-duplex and errors stop incrementing.

Answer

Enter interface configuration mode and issue the 'speed 100' and 'duplex full' commands to ensure both sides are set to the same values.

Answer

Enter interface configuration mode and issue the 'no shutdown' command to bring the interface up.

Answer

Enter interface configuration mode and issue the 'duplex half' command to match the remote side's duplex setting.

Question 8

You are connected to R1 via the console. R1 has two directly connected routers: R2 and R3. Currently, R1 cannot reach R2's loopback interface (203.0.113.1/32). Additionally, R3 is IPv6-only and must be reachable from R1 using a statically assigned global unicast address. Configure R1's interfaces and static routes so that: (1) R1 can ping R2's loopback, (2) R1 can ping R3's IPv6 address 2001:db8:acad:2::1/64, and (3) R1's IPv6 address on the link to R3 is derived using EUI-64.

Accepted Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.1/32 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:2::/64 eui-64.. The ping to R2's loopback fails because R1's G0/0 is configured with a /24 mask, but the network should be /24 (which is correct), but the loopback is on a different subnet (203.0.113.0/24 vs 192.168.1.0/24). Actually the issue is that R1 has no route to 203.0.113.1. The solution is to add a static route on R1 pointing to R2's G0/0 IP. For IPv6, R1's EUI-64 address is on the wrong subnet (2001:db8:acad:1::/64) but R3 is on 2001:db8:acad:2::/64. The fix is to change the IPv6 address on R1's G0/1 to 2001:db8:acad:2::/64 eui-64. Then add an IPv6 static route if needed (but R1 and R3 are directly connected, so after fixing the subnet, ping should work).

Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.0/24 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:1::/64 eui-64.

Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.1/32 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:2::1/64.

Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.1/32 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:1::/64 eui-64.

Question 9

You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces so that R1 can reach R2's loopback0 (192.0.2.1/32) and R2's IPv6 loopback0 (2001:db8:1::1/64). R1 has a misconfigured subnet mask on G0/0 and is missing its default gateway. Additionally, R1 has a duplicate IPv4 address on G0/1 that must be corrected. Use EUI-64 for R1's IPv6 link-local address on G0/0 and static IPv6 for the global unicast address on G0/1.

Accepted Answer

Change G0/0 mask to /30, add default route via 10.0.0.2, change G0/1 IP to 192.0.2.2/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:2::1/64 to G0/1. Ly fixes the subnet mask on G0/0 to /30, adds the default gateway via 10.0.0.2, resolves the duplicate IP on G0/1 by assigning 192.0.2.2/30, and sets up IPv6 addressing as required (EUI-64 on G0/0 and static 2001:db8:2::1/64 on G0/1). However, for full IPv6 reachability to R2's loopback0 (2001:db8:1::1/64), R1 also needs an IPv6 route (e.g., a static route to 2001:db8:1::/64 via R2's link-local or global address on G0/1). Without this, Option A only ensures IPv4 connectivity but not IPv6. Among the given options, A is the best because it addresses all IPv4 issues and the IPv6 addressing requirements, though it is incomplete for IPv6 routing.

Answer

Change G0/0 mask to /24, add default route via 10.0.0.1, change G0/1 IP to 10.0.0.6/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:1::1/64 to G0/1

Answer

Change G0/0 mask to /30, add default route via 10.0.0.1, change G0/1 IP to 192.0.2.2/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:2::1/64 to G0/1

Answer

Change G0/0 mask to /30, add default route via 10.0.0.2, change G0/1 IP to 10.0.0.6/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:2::1/64 to G0/1

Question 10

You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces and verify reachability to R2. The current configuration has a wrong subnet mask on G0/0, missing default gateway for IPv4, and R1's IPv6 address is configured using EUI-64 while R2 uses a static IPv6 address. Fix these issues so that R1 can ping both R2's IPv4 and IPv6 addresses.

Accepted Answer

Change R1 G0/0 subnet mask to /30, add a default route via 192.0.2.2, and configure a static IPv6 address 2001:db8:1::1/64 on G0/0.. The problem had three issues: (1) R1's G0/0 subnet mask was /24 (255.255.255.0) but R2's G0/0 was /30 (255.255.255.252), causing an IP subnet mismatch. (2) R1 lacked a default gateway for IPv4; the static route pointed to 192.0.2.254 which is not reachable. (3) R1's IPv6 EUI-64 configuration on G0/0 generates an interface ID from the MAC, but R2 expects a static address 2001:db8:1::2/64, so R1 must use a static IPv6 address on the same subnet. The fix: change R1's G0/0 mask to /30, add a default route via R2's G0/0 IP (192.0.2.2), and configure a static IPv6 address (e.g., 2001:db8:1::1/64) on R1's G0/0.

Answer

Change R1 G0/0 subnet mask to /30, add a default route via 192.0.2.254, and keep the EUI-64 IPv6 address on G0/0.

Answer

Change R1 G0/0 subnet mask to /24, add a default route via 192.0.2.2, and configure a static IPv6 address 2001:db8:1::1/64 on G0/0.

Answer

Change R1 G0/0 subnet mask to /30, add a default route via 192.0.2.2, and keep the EUI-64 IPv6 address on G0/0.

Question 11

You are connected to R1 via console. The network consists of R1, R2, and a multilayer switch MLS1. R1's GigabitEthernet0/0 connects to MLS1's GigabitEthernet1/0/1 (VLAN 10), and MLS1's GigabitEthernet1/0/2 connects to R2's GigabitEthernet0/0. The goal is to enable IPv6 communication between R1 and R2 across the layer-3 switch. Currently, R1 and R2 cannot ping each other's IPv6 addresses. Configure R1's G0/0 with the IPv6 prefix 2001:db8:1:10::/64 using EUI-64, and R2's G0/0 with static IPv6 address 2001:db8:1:10::2/64. Also ensure MLS1 has IPv6 routing enabled and an IPv6 address on VLAN 10 (2001:db8:1:10::3/64). Troubleshoot and fix any layer-2 or layer-3 issues preventing connectivity.

Accepted Answer

Configure 'ipv6 address 2001:db8:1:10::/64 eui-64' on R1's G0/0 interface.. R1 has no IPv6 address configured on G0/0. The required prefix is 2001:db8:1:10::/64 using EUI-64, which generates the interface ID from the MAC address. The command 'ipv6 address 2001:db8:1:10::/64 eui-64' must be entered in interface configuration mode. Additionally, MLS1 has IPv6 routing enabled (as seen by the connected route), but R1's interface is missing the IPv6 address. After configuration, R1 will be able to ping R2 and MLS1. No other changes are needed because R2 and MLS1 are correctly configured.

Answer

Enable IPv6 routing on R1 with 'ipv6 unicast-routing'.

Answer

Configure 'ipv6 address 2001:db8:1:10::1/64' on R1's G0/0 interface (without EUI-64).

Answer

Change the VLAN on MLS1's G1/0/1 to match R1's VLAN.

Question 12

You are connected to R1 via console. R1 and R2 are directly connected via GigabitEthernet0/0. Your task is to configure IPv4 and IPv6 addressing on both routers so that they can ping each other's IPv4 and IPv6 addresses. The current configuration has intentional faults: R1's IPv4 subnet mask is incorrect, R2 is missing its default gateway, and R1's IPv6 address uses EUI-64 but is not working due to a duplicate IP. Correct the IPv4 mask on R1, assign a static IPv6 address on R2, and ensure both routers can reach each other.

Accepted Answer

On R1, change the IPv4 mask to 255.255.255.252; on R2, assign IPv4 address 192.0.2.2/30 and IPv6 address 2001:db8:1::2/64; configure a default route on R2 pointing to 192.0.2.1.. R1's IPv4 mask was /28, but the correct mask for the link should be /30 to avoid overlapping subnets (192.0.2.0/28 includes both .1 and .14, but they are on the same link). R2 had no IPv6 address configured. Additionally, R1's EUI-64 address was valid but R2 needed a static IPv6 address. The solution: on R1, change the mask to 255.255.255.252; on R2, assign an IPv4 address with mask /30 and a static IPv6 address 2001:db8:1::2/64; also add a default route on R2 pointing to 192.0.2.1 for IPv4. After these changes, both routers can ping each other's IPv4 and IPv6 addresses.

Answer

On R1, change the IPv4 mask to 255.255.255.0; on R2, assign IPv4 address 192.0.2.2/24 and IPv6 address 2001:db8:1::2/64; no default route needed.

Answer

On R1, change the IPv4 mask to 255.255.255.252; on R2, assign IPv4 address 192.0.2.2/28 and IPv6 address 2001:db8:1::2/64; configure a default route on R2 pointing to 192.0.2.1.

Answer

On R1, change the IPv4 mask to 255.255.255.252; on R2, assign IPv4 address 192.0.2.2/30 and IPv6 address 2001:db8:1::1/64; configure a default route on R2 pointing to 192.0.2.1.

Question 13

You are connected to R1. The network administrator has partially configured IPv4 and IPv6 on the interfaces. However, PC1 (connected to R1's G0/1) cannot reach PC2 (connected to R2's G0/1). Configure R1 and R2 so that PC1 can ping PC2. Fix any addressing errors. Use IPv4 subnet 192.0.2.0/30 for the link between R1 and R2, and 198.51.100.0/24 for the PC LANs. For IPv6, use 2001:db8:1::/64 on R1's G0/1 and 2001:db8:2::/64 on R2's G0/1, with R1's G0/1 using EUI-64 and R2's G0/1 using a static address 2001:db8:2::1/64.

Accepted Answer

On R1, change the subnet mask on G0/0 from /24 to /30. On R1 G0/1, issue 'ipv6 address 2001:db8:1::/64 eui-64' and 'no shutdown'. Enable 'ipv6 unicast-routing' globally on both routers.. The issue is a subnet mask mismatch on the link between R1 and R2: R1 uses /24 (255.255.255.0) while R2 uses /30 (255.255.255.252). This prevents R1 from having a route to R2's LAN. Fix R1's G0/0 mask to /30. Additionally, R1's G0/1 IPv6 EUI-64 command is missing the interface identifier; the correct command is 'ipv6 address 2001:db8:1::/64 eui-64' but the interface must be enabled with 'no shutdown'. Also ensure IPv6 unicast-routing is enabled. The PCs have correct gateways.

Answer

On R1, change the subnet mask on G0/0 from /24 to /30. On R1 G0/1, issue 'ipv6 address 2001:db8:1::/64 eui-64' and 'no shutdown'. No need to enable IPv6 unicast-routing because it is on by default.

Answer

On R1, change the subnet mask on G0/0 from /24 to /30. On R1 G0/1, issue 'ipv6 address 2001:db8:1::/64' (without eui-64) and 'no shutdown'. Enable 'ipv6 unicast-routing' globally on both routers.

Answer

On R1, change the subnet mask on G0/0 from /24 to /30. On R1 G0/1, issue 'ipv6 address 2001:db8:1::/64 eui-64' and 'no shutdown'. Enable 'ipv6 unicast-routing' globally on both routers. Also, change the default gateway on PC1 to 2001:db8:1::1.

Question 14

You are connected to R1. Configure IPv4 and IPv6 addressing on R1's GigabitEthernet0/0 and GigabitEthernet0/1 interfaces so that R1 can ping both R2's IPv4 address (203.0.113.2) and R2's IPv6 address (2001:db8:1::2). The current configuration has an incorrect subnet mask on G0/0, missing default gateway, and R1's G0/1 has a duplicate IPv4 address with R3. Also, use EUI-64 for IPv6 on G0/0 and static IPv6 assignment on G0/1. Ensure all issues are resolved and connectivity verified.

Accepted Answer

Change G0/0 subnet mask to 255.255.255.252, add default gateway 203.0.113.2, change G0/1 IPv4 to 192.168.1.254, enable IPv6 routing, configure G0/0 with ipv6 address 2001:db8:1::/64 eui-64, and G0/1 with ipv6 address 2001:db8:2::1/64.. The subnet mask on G0/0 was incorrectly set to /24 instead of /30. While a /24 mask on 203.0.113.1 would include 203.0.113.2 in the same subnet from R1's perspective, the mismatch with R2's /30 mask leads to inconsistent subnet definitions and potential ARP or routing issues. Additionally, no default gateway was configured, so traffic to remote networks would fail. On G0/1, the IPv4 address 192.168.1.1 was already used by R3, causing a duplicate IP conflict. IPv6 was not configured on either interface. The fix involved correcting the subnet mask on G0/0 to 255.255.255.252, adding a default gateway (203.0.113.2), assigning a unique IPv4 address to G0/1 (192.168.1.254), enabling IPv6 routing globally with `ipv6 unicast-routing`, configuring EUI-64 on G0/0 (`ipv6 address 2001:db8:1::/64 eui-64`), and static IPv6 on G0/1 (`ipv6 address 2001:db8:2::1/64`).

Answer

Change G0/0 subnet mask to 255.255.255.0, add default gateway 203.0.113.1, change G0/1 IPv4 to 192.168.1.254, enable IPv6 routing, configure G0/0 with ipv6 address 2001:db8:1::1/64, and G0/1 with ipv6 address 2001:db8:2::1/64.

Answer

Change G0/0 subnet mask to 255.255.255.252, add default gateway 203.0.113.2, change G0/1 IPv4 to 192.168.1.1, enable IPv6 routing, configure G0/0 with ipv6 address 2001:db8:1::/64 eui-64, and G0/1 with ipv6 address 2001:db8:2::1/64.

Answer

Change G0/0 subnet mask to 255.255.255.252, add default gateway 203.0.113.2, change G0/1 IPv4 to 192.168.1.254, enable IPv6 routing, configure G0/0 with ipv6 address 2001:db8:1::1/64, and G0/1 with ipv6 address 2001:db8:2::/64 eui-64.

Question 15

You are connected to R1. The network has R1, R2, and a multilayer switch MLS1. Configure IPv4 and IPv6 addressing on R1's interfaces so that R1 can ping both R2 (198.51.100.2) and MLS1 (203.0.113.2) via IPv4. Additionally, configure IPv6 on G0/1 using EUI-64 with prefix 2001:db8:1::/64 and verify that R1 can ping the IPv6 address of MLS1 (2001:db8:1::2). The current configuration has incorrect subnet masks and missing IPv6 settings, causing reachability failures.

Accepted Answer

Change the subnet mask on G0/0 to 255.255.255.252, change G0/1 to 255.255.255.252, then configure IPv6 on G0/1 with the EUI-64 address using the prefix 2001:db8:1::/64.. The interfaces on R1 were configured with subnet masks that were not /30, which is required for these point-to-point links. With an incorrect mask, R1 does not consider the neighboring IPs (198.51.100.2 and 203.0.113.2) as directly connected, preventing ARP resolution and IPv4 reachability. Additionally, IPv6 was missing on G0/1. To fix, change the subnet mask on G0/0 to 255.255.255.252, change G0/1 to 255.255.255.252, then configure IPv6 on G0/1 with the EUI-64 address using the prefix 2001:db8:1::/64. After these changes, pings succeed.

Answer

Change the subnet mask on G0/0 to 255.255.255.0, change G0/1 to 255.255.255.0, then configure IPv6 on G0/1 with the EUI-64 address using the prefix 2001:db8:1::/64.

Answer

Change the subnet mask on G0/0 to 255.255.255.252, change G0/1 to 255.255.255.252, then configure IPv6 on G0/1 with the static address 2001:db8:1::1/64.

Answer

Change the subnet mask on G0/0 to 255.255.255.252, change G0/1 to 255.255.255.252, then configure IPv6 on G0/1 with the EUI-64 address using the prefix 2001:db8:1::/32.