300-410 Practice Test 25 — 15 Questions

Question 1

An engineer is troubleshooting an OSPF network where route summarization is configured on an ABR. Which TWO statements correctly describe the behavior of OSPF inter-area route summarization using the 'area range' command? (Choose TWO.)

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The 'area range' command creates a single Type 3 LSA for the summary prefix and suppresses the advertisement of individual Type 3 LSAs for the component networks.. The 'area range' command on an ABR summarizes routes from one area into another. It creates a single Type 3 LSA for the summary prefix, suppresses the individual Type 3 LSAs for the component networks, and does not affect Type 1 or Type 2 LSAs within the area. The summary LSA is advertised with a cost equal to the highest cost among the component routes, not the lowest. The command does not automatically summarize redistributed routes; that requires the 'summary-address' command under the OSPF process.

Answer

The cost of the summary LSA is set to the lowest cost among the component routes within the range.

Answer

The 'area range' command also summarizes external routes redistributed into OSPF from other protocols.

Answer

The summary route is advertised with a metric type of E1 or E2, depending on the original external metric type.

Question 2

Examine this partial configuration on router R5:

flow record RECORD-3
 match ipv4 source address
 match ipv4 destination address
 match ipv4 protocol
 collect routing source as
 collect routing destination as
!
flow monitor MONITOR-5
 record RECORD-3
 cache timeout active 60
!
interface GigabitEthernet0/5
 ip flow monitor MONITOR-5 input
!

What is missing or incorrect in this configuration?

Accepted Answer

The router must have BGP configured and the flow record must include 'match ipv4 bgp source-as' and 'match ipv4 bgp destination-as' to collect AS numbers.. This question tests knowledge of BGP AS number collection requirements in Flexible NetFlow.

Answer

The flow record is missing 'match ipv4 source prefix-length' and 'match ipv4 destination prefix-length' to collect AS numbers.

Answer

The flow monitor is missing the 'cache timeout inactive' command to properly age out flows.

Answer

The configuration is correct; AS numbers will be collected automatically from the routing table.

Question 3

What is the default active flow timeout value in Cisco IOS Flexible NetFlow?

Accepted Answer

1800 seconds. This question tests recall of default timer values in Flexible NetFlow.

Answer

60 seconds

Answer

300 seconds

Answer

30 seconds

Question 4

Which NetFlow version is the default export format when using Flexible NetFlow with the 'record netflow ipv4 original-input' command?

Accepted Answer

NetFlow version 9. This question tests knowledge of the default export version for Flexible NetFlow predefined records.

Answer

NetFlow version 5

Answer

IPFIX (NetFlow version 10)

Answer

NetFlow version 1

Question 5

A network engineer is troubleshooting an OSPF adjacency that is flapping between two routers. The adjacency forms and then drops repeatedly. Both routers are configured for BFD on the OSPF interface. The engineer checks the BFD session and sees it is up, but the OSPF neighbor state transitions from FULL to DOWN every few seconds. What is the most likely cause of this issue?

Accepted Answer

The OSPF dead interval is mismatched between the two routers.. The BFD session is up, so BFD is not causing the flap. The issue is likely a mismatch in OSPF parameters that causes the adjacency to reset independently of BFD.

Answer

The BFD timers are set too low on one router.

Answer

The interface is flapping due to a physical issue.

Answer

BFD is configured with the 'strict-mode' command, causing OSPF to ignore BFD state.

Question 6

What is the default IKE (ISAKMP) lifetime value in Cisco IOS for IPsec Site-to-Site VPN?

Accepted Answer

86400 seconds (24 hours). The default IKE (ISAKMP) lifetime in Cisco IOS for IPsec Site-to-Site VPN is 86400 seconds (24 hours). This value is defined in the ISAKMP policy and controls how long the IKE Phase 1 security association (SA) remains active before requiring re-authentication. A longer lifetime reduces the overhead of re-establishing the Phase 1 tunnel, balancing security with performance.

Answer

3600 seconds (1 hour)

Answer

28800 seconds (8 hours)

Answer

180 seconds (3 minutes)

Question 7

Which TWO statements about the 'logging buffered' command and its interaction with other logging commands are correct? (Choose TWO.)

Accepted Answer

The command 'logging buffered 4096' sets the buffer size to 4096 bytes and enables logging to the buffer.. The 'logging buffered' command enables logging to an internal buffer. The size can be specified in bytes. The 'logging console' and 'logging buffered' are independent; disabling one does not affect the other. The 'logging monitor' controls terminal line logging. The 'logging on' command globally enables logging output; without it, no logging occurs. The 'no logging buffered' command disables buffer logging but does not clear the buffer.

Answer

Disabling console logging with 'no logging console' also disables buffered logging.

Answer

The 'logging buffered' command requires 'logging on' to be configured first; otherwise, it has no effect.

Answer

The 'no logging buffered' command clears the buffer and stops all logging to the buffer.

Question 8

What is the default BFD interval and multiplier on Cisco IOS-XE devices when BFD is enabled under an interface without explicit timer configuration?

Accepted Answer

interval 150 ms, min_rx 150 ms, multiplier 3. If no BFD timers are configured under the interface, the default values are: interval = 150 ms, min_rx = 150 ms, multiplier = 3. These are the defaults used when 'bfd interval' is not specified.

Answer

interval 100 ms, min_rx 100 ms, multiplier 3

Answer

interval 200 ms, min_rx 200 ms, multiplier 5

Answer

interval 50 ms, min_rx 50 ms, multiplier 3

Question 9

According to RFC 5880, what is the maximum number of BFD sessions that can be uniquely identified using the discriminator fields?

Accepted Answer

2^32 (4,294,967,296). The discriminator fields are 32-bit values, allowing up to 2^32 (approximately 4.29 billion) unique session identifiers.

Answer

2^16 (65536)

Answer

2^24 (16,777,216)

Answer

Unlimited

Question 10

Drag and drop the steps to troubleshoot suboptimal routing due to incorrect Administrative Distance values into the correct order, from first to last.

Accepted Answer

Examine the routing table for the destination prefix. The correct order begins by identifying the routing table entries to see which routes are preferred, then checking the AD values of the competing protocols, verifying the configuration of the protocol with the lower AD, adjusting the AD on the desired protocol to make it preferred, and finally confirming the routing table update.

Question 11

Which TWO statements about DHCP IPv6 (DHCPv6) operation are true? (Choose TWO.)

Accepted Answer

DHCPv6 servers listen on UDP port 547.. DHCPv6 servers listen on UDP port 547, while DHCPv6 clients use UDP port 546. This is defined in RFC 3315 and is a key distinction from DHCPv4, where servers listen on port 67 and clients on port 68. The server uses port 547 to receive requests from clients, ensuring proper separation of DHCPv6 traffic.

Answer

DHCPv6 can only be used in stateless mode.

Answer

DHCPv6 uses UDP ports 67 and 68, just like DHCPv4.

Answer

DHCPv6 relies on ARP to discover DHCPv6 servers.

Question 12

Which authentication type is the default when BFD authentication is enabled on Cisco IOS-XE?

Accepted Answer

Keyed SHA-1 (auth type 4). Cisco IOS-XE defaults to keyed SHA-1 (auth type 4) when BFD authentication is configured, as it provides stronger security than MD5.

Answer

Simple password (auth type 1)

Answer

Keyed MD5 (auth type 2)

Answer

Meticulous Keyed MD5 (auth type 3)

Question 13

Drag and drop the steps to verify and validate BFD operational state into the correct order, from first to last.

Accepted Answer

Display summary of BFD neighbors with show bfd neighbors. Begin with a high-level summary of all BFD sessions, then examine detailed session information, validate timers and counters, confirm BFD is active for the routing protocol, and finally test failover behavior by disabling the peer interface.

Question 14

Which statement correctly describes the default 'match' direction in a Flexible NetFlow flow record?

Accepted Answer

The default match direction is 'input' (ingress).. The default match direction is 'input' (ingress), meaning flows are matched on incoming traffic only.

Answer

The default match direction is 'output' (egress).

Answer

The default match direction is 'both' (input and output).

Answer

There is no default direction; it must always be specified.

Question 15

A network engineer is troubleshooting a router that is not responding to ICMP echo requests from a management station at 10.10.10.1. The router has an ACL applied to the VTY lines that permits only 10.10.10.0/24. The engineer can telnet to the router from the management station. What is the most likely cause?

Accepted Answer

An inbound ACL on the interface denies ICMP from 10.10.10.1.. The management station can telnet to the router, which proves that the VTY ACL permits 10.10.10.0/24 and that reachability exists. Since ICMP is processed by the interface input path before any VTY ACL, the failure of ICMP echo requests points to an inbound ACL on the interface that explicitly denies ICMP from 10.10.10.1. This is the most likely cause because telnet (TCP/23) succeeds while ICMP fails, isolating the issue to interface-level filtering.

Answer

The VTY ACL also applies to ICMP traffic.

Answer

The router has 'no ip icmp echo' configured globally.

Answer

The management station is not in the routing table of the router.