300-410 Practice Test 5 — 25 Questions

Question 1

Which BFD packet type is used for initial session establishment and carries the discriminator values?

Accepted Answer

BFD Control packets. BFD Control packets are used for session establishment, carrying local and remote discriminator values, and are sent periodically to maintain the session.

Answer

BFD Echo packets

Answer

BFD Poll packets

Answer

BFD Hello packets

Question 2

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 3

What is the default CoPP behavior for traffic that does not match any class in the policy-map?

Accepted Answer

Transmitted. By default, Control Plane Policing (CoPP) uses a class-default in the policy-map that implicitly permits (transmits) all traffic not explicitly matched by a user-defined class. This default behavior ensures that only traffic matching a class with a 'drop' action is policed, preventing unintentional denial of service from misconfigured policies.

Answer

Dropped

Answer

Logged and dropped

Answer

Routed to the management plane

Question 4

An engineer configures iBGP between two routers in the same AS. The BGP session comes up, but the routes learned from the eBGP neighbor are not installed in the routing table. The IGP does not carry the BGP next-hop address. Which is the most likely explanation?

Accepted Answer

The BGP next-hop is not reachable because the IGP does not advertise it, and no static route exists.. For a BGP route to be installed in the routing table, the next-hop address must be reachable via the IGP or a static route. Since the IGP does not carry the BGP next-hop address and no static route exists, the next-hop is unreachable, causing the route to remain in the BGP table but not be installed in the routing table.

Answer

The BGP synchronization rule is enabled, causing the route to be suppressed until the IGP learns it.

Answer

The next-hop-self command is missing on the eBGP neighbor, so the iBGP router sees the external next-hop.

Answer

The BGP table shows the route as valid, but the routing table does not install it due to administrative distance.

Question 5

What is the default behavior of an IPv4 access control list (ACL) when no explicit permit or deny statement matches a packet?

Accepted Answer

The packet is denied.. By default, IPv4 ACLs have an implicit deny any statement at the end. If a packet does not match any explicit permit or deny entry, the implicit deny any is applied, causing the packet to be dropped. This behavior is fundamental to ACL security, ensuring that only explicitly permitted traffic is allowed.

Answer

The packet is permitted.

Answer

The packet is logged and then permitted.

Answer

The ACL is ignored and the packet is forwarded.

Question 6

A network engineer runs the following command on Router R1:

R1# show snmp statistics

SNMP packets input: 150
    Bad SNMP version errors: 0
    Unknown community name: 25
    Illegal operation for community name: 0
    Encoding errors: 0
    Number of requested variables: 300
    Number of altered variables: 0
    Get-request PDUs: 120
    Get-next PDUs: 30
    Set-request PDUs: 0
SNMP packets output: 200
    Too big errors: 0
    No such name errors: 10
    Bad values errors: 0
    General errors: 0
    Response PDUs: 200
    Trap PDUs: 0

Based on this output, which statement is correct?

Accepted Answer

There are 25 SNMP requests with invalid community strings.. The 'Unknown community name: 25' counter indicates that 25 incoming SNMP packets contained a community string that did not match any configured community on Router R1. This means those requests were rejected due to invalid community strings, making option A correct.

Answer

The router has sent 150 trap PDUs.

Answer

There were 10 set requests that failed due to bad values.

Answer

The router received 200 SNMP packets.

Question 7

A network engineer runs the following command on router R4:

R4# show monitor session 9
Session 9
---------
Type : ERSPAN Source Session
Status : Admin Disabled
Source Ports :
    Both : Gi0/2
Destination IP : 192.168.2.20
Origin IP : 10.0.0.3
ERSPAN ID : 200

Based on this output, which statement is correct?

Accepted Answer

The ERSPAN session is configured but not currently active because it is administratively disabled.. The output explicitly shows 'Status : Admin Disabled', which means the ERSPAN source session has been configured but has not been activated by the administrator. In Cisco IOS, an ERSPAN session remains in this state until the 'no shutdown' command is issued under the monitor session configuration. Therefore, the session is not currently mirroring traffic, making option A the correct statement.

Answer

The ERSPAN session is actively mirroring traffic from Gi0/2 to 192.168.2.20.

Answer

The ERSPAN session is using RSPAN because the status is disabled.

Answer

The ERSPAN session is misconfigured because the origin IP is missing.

Question 8

In ERSPAN, what is the default encapsulation type used for transporting mirrored packets across an IP network?

Accepted Answer

GRE. ERSPAN uses GRE (Generic Routing Encapsulation) to encapsulate the original packets for transport over an IP network.

Answer

IPsec

Answer

MPLS

Answer

VXLAN

Question 9

Drag and drop the steps to troubleshoot route summarization adjacency or connectivity failures into the correct order, from first to last.

Accepted Answer

Verify the summarization router has a null0 route. Start by verifying that the summarization router has a route to the null0 interface to prevent loops. Then, confirm that the summary route is being advertised to neighbors using show ip route. Next, check that the neighbor router receives the summary in its routing table. After that, examine the neighbor's routing table for the specific summarized prefix. Finally, test end-to-end connectivity using ping or traceroute to ensure the summary works.

Question 10

Which TWO statements about SNMPv3 configuration on Cisco IOS XE are true? (Choose TWO.)

Accepted Answer

The 'snmp-server user' command can specify an authentication and privacy password for a user.. Option B is correct because the 'snmp-server user' command on Cisco IOS XE allows you to configure a user with authentication (auth) and privacy (priv) passwords, e.g., 'snmp-server user user1 group1 v3 auth sha authpass priv aes 128 privpass', which sets both the authentication and encryption credentials. Option D is correct because when configuring SNMPv3 traps or informs with 'snmp-server host', you must specify the username (and optionally the security level) so the device knows which SNMPv3 user credentials to use when sending notifications, e.g., 'snmp-server host 192.0.2.1 traps version 3 priv user1'. Option A is incorrect because 'snmp-server group' creates an SNMPv3 group and associates it with a security model and access level, but it does not assign a username; users are assigned to groups via the 'snmp-server user' command. Option C is incorrect because the SNMP engine ID is automatically generated by default, but it can be manually configured using the 'snmp-server engineID local' command. Option E is incorrect because SNMPv3 supports three security levels: noAuthNoPriv, authNoPriv, and authPriv, not only authPriv.

Answer

The 'snmp-server group' command creates a group and assigns a username to it.

Answer

The engine ID is automatically generated and cannot be manually configured.

Answer

SNMPv3 supports only the authPriv security level.

Question 11

Drag and drop the steps to configure and schedule an IP SLA ICMP-echo operation into the correct order, from first to last.

Accepted Answer

Enter IP SLA configuration mode using 'ip sla 1'. The correct order begins by entering IP SLA configuration mode, then defining the ICMP-echo operation with target and source, setting optional parameters like frequency, scheduling the operation to start immediately or at a specific time, and finally verifying the configuration with show commands.

Question 12

A network engineer runs the following command on Router R1:

R1# show crypto ipsec sa peer 10.1.1.2
interface: Tunnel0
    Crypto map tag: VPN-MAP, local addr 10.1.1.1
   protected vrf: (none)
   local  ident (addr/mask/prot/port): (10.1.1.0/255.255.255.0/0/0)
   remote ident (addr/mask/prot/port): (192.168.1.0/255.255.255.0/0/0)
   current_peer 10.1.1.2 port 500
     PERMIT, flags={origin_is_acl,}
    #pkts encaps: 100, #pkts encrypt: 100, #pkts digest: 100
    #pkts decaps: 0, #pkts decrypt: 0, #pkts verify: 0
    #send errors 0, #recv errors 0

Based on this output, what is the problem?

Accepted Answer

The remote peer is not sending traffic back; check routing on the remote router.. The outbound packet count (encaps) is 100, but inbound (decaps) is 0. This suggests that traffic is being sent through the tunnel but no responses are being received, possibly due to a routing issue on the remote side or a firewall blocking return traffic.

Answer

The tunnel is working correctly; all packets are being encrypted and decrypted.

Answer

The local crypto ACL is misconfigured; it is not matching traffic.

Answer

The IPsec SA is not established; the tunnel is down.

Question 13

A router has CoPP configured with a class-map that matches OSPF traffic and polices it to 2000 pps. The router is also configured with an OSPF distribute-list in to filter routes. After applying CoPP, OSPF neighbors form, but routes from a specific neighbor are missing. The distribute-list permits all routes. Which is the most likely explanation?

Accepted Answer

CoPP drops OSPF LSU packets, preventing route installation, while hello packets still form the adjacency.. OSPF uses Hello packets to establish and maintain neighbor adjacencies, but route information is exchanged via Link State Update (LSU) packets. The CoPP policy matches OSPF traffic and polices it to 2000 pps, which can drop LSU packets if the rate is exceeded, preventing route installation while allowing enough Hello packets to keep the adjacency up. The distribute-list permits all routes, so it is not the cause of the missing routes.

Answer

The distribute-list is applied incorrectly and blocks all routes.

Answer

OSPF uses TCP, and CoPP only polices UDP.

Answer

The CoPP policy is applied to the wrong control plane subinterface.

Question 14

A network engineer runs the following command to verify DMVPN tunnel status:

R1# show ip nhrp detail

10.0.0.2/32 via Tunnel0
   Created: 00:10:15, Expire: 01:49:45
   Type: dynamic, Flags: unique registered
   NBMA: 192.168.1.2
   (no socket)

What does this output indicate?

Accepted Answer

The spoke 10.0.0.2 has registered with the hub and its NBMA address is 192.168.1.2.. The output shows a dynamic NHRP cache entry for a spoke (10.0.0.2) with NBMA address 192.168.1.2, indicating the spoke has registered and the entry is valid.

Answer

The spoke 10.0.0.2 is using a static NBMA mapping.

Answer

The NHRP entry is about to expire and needs re-registration.

Answer

The spoke has not registered; the entry is incomplete.

Question 15

An engineer configures mutual redistribution between OSPF and EIGRP on a router. After a few minutes, the router's CPU spikes and routes start flapping. Which is the most likely explanation?

Accepted Answer

The redistribution is creating a routing loop because there is no route tagging or filtering to prevent re-redistribution.. Mutual redistribution without route tagging or filtering causes the redistributed routes to be re-injected back into the original routing protocol, creating a routing loop. This loop leads to continuous route updates, CPU spikes, and route flapping as the router repeatedly processes and advertises the same prefixes.

Answer

The seed metric is not configured, so the routes are not redistributed.

Answer

The administrative distance is set too low, causing the router to prefer the wrong route.

Answer

The OSPF process ID is the same on both routers.

Question 16

Which BGP attribute is considered 'well-known mandatory' and must be present in all BGP update messages?

Accepted Answer

AS_PATH. The AS_PATH attribute is well-known mandatory, meaning it must be included in all BGP updates. Other well-known mandatory attributes include NEXT_HOP and ORIGIN.

Answer

LOCAL_PREF

Answer

MED

Answer

COMMUNITY

Question 17

A network engineer runs the following command to verify BFD operation:

R1# show bfd neighbors detail

IPv4 Sessions
NeighAddr      LD/RD         RH/RS     State     Int
10.1.1.2      1/2           Up        Up        Gi0/0
Session state is UP and not using echo function.
Session type: single-hop
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 1000000, Received Multiplier: 3
Holddown (hits): 0 (0), Hello (hits): 1000/5
Rx Count: 1000, Rx Interval (ms) min/max/avg: 900/1100/1000
Tx Count: 1000, Tx Interval (ms) min/max/avg: 900/1100/1000

What does this output indicate?

Accepted Answer

BFD session is operating with async mode, intervals at 1 second.. The output shows a BFD session in UP state with consistent transmit and receive intervals around 1000 ms, no echo function, and a multiplier of 3. The session is healthy.

Answer

BFD session is using echo mode for fast failure detection.

Answer

BFD session is down and not sending hellos.

Answer

BFD session has a holddown timer of 3 seconds.

Question 18

A network engineer runs the following command to troubleshoot a VRF-Lite CoPP issue:

R1# show policy-map control-plane input class CoPP-ACL vrf CUSTOMER_I

Output:
  Class-map: CoPP-ACL (match-all)
    0 packets, 0 bytes
    5 minute offered rate 0 bps, drop rate 0 bps
    Match: access-group 100
    police:
        cir 8000 bps, bc 1500 bytes, be 1500 bytes
      conformed 0 packets, 0 bytes; actions:
        transmit
      exceeded 0 packets, 0 bytes; actions:
        drop
      violated 0 packets, 0 bytes; actions:
        drop

What does this output indicate?

Accepted Answer

The CoPP policy is rate-limiting traffic to 8000 bps, but no traffic has matched the class yet.. The output shows '0 packets, 0 bytes' matched and a 5-minute offered rate of 0 bps, meaning no traffic has hit the class-map yet. The police stanza confirms the policy is configured to rate-limit matching traffic to a CIR of 8000 bps with a 1500-byte burst, but since no packets have matched access-group 100, no conform/exceed/violate counters have incremented. This indicates the CoPP policy is armed and applied, but simply idle.

Answer

The CoPP policy is dropping all packets that match access-group 100.

Answer

The CoPP policy has matched many packets and is dropping them due to exceeding the rate.

Answer

The CoPP policy is not applied to the control plane for this VRF.

Question 19

A network engineer runs the following command to verify Flexible NetFlow record configuration:

R1# show flow record FLOW-RECORD-1

flow record FLOW-RECORD-1
    match ipv4 source address
    match ipv4 destination address
    match ip protocol
    collect counter bytes
    collect counter packets
    collect timestamp sys-uptime first
    collect timestamp sys-uptime last

What does this output indicate?

Accepted Answer

The record matches on source and destination IP addresses and protocol, and collects byte/packet counters and timestamps.. The output shows the definition of a Flexible NetFlow record. It matches on source IP, destination IP, and protocol, and collects byte and packet counters along with timestamps for the first and last packet of the flow.

Answer

The record collects only packet counts, not byte counts.

Answer

The record does not include any timestamp information.

Answer

The record matches on TCP flags.

Question 20

Which of the following is a valid 'set' action in a PBR route-map?

Accepted Answer

set ip next-hop 10.0.0.1. In Cisco PBR (Policy-Based Routing) route-maps, 'set ip next-hop 10.0.0.1' is a valid set action that specifies the next-hop IP address for matching packets, overriding the normal routing table lookup. This is one of the most commonly used PBR set commands and is supported in route-map configuration mode.

Answer

set metric 100

Answer

set tag 5

Answer

set community 100:100