300-410 Practice Exam 59 — 20 Questions

Question 1

A network engineer runs the following command to verify IPv6 binding table:

R1# show ipv6 neighbors binding

IPv6 Address                     Age  Link-layer Addr  State  Interface  VLAN  Policy
2001:db8::1                      10   0011.2233.4455  REACH  Fa0/1      10    TRUSTED
2001:db8::2                      5    00aa.bbcc.ddee  STALE  Fa0/0      10    INSPECT
2001:db8::3                      0    1111.2222.3333  INCOMP Fa0/0      10    -

What does this output indicate?

Accepted Answer

The binding table shows three entries: one reachable on trusted port, one stale on untrusted port, and one incomplete, indicating active ND learning.. The output of 'show ipv6 neighbors binding' displays the IPv6 binding table used in First Hop Security (FHS) features like IPv6 Snooping. The entry for 2001:db8::1 has a REACH state on interface Fa0/1 with a TRUSTED policy, indicating it is reachable on a trusted port. The entry for 2001:db8::2 is STALE on Fa0/0 with an INSPECT policy, meaning it is on an untrusted port and requires verification. The entry for 2001:db8::3 is INCOMP (incomplete) on Fa0/0, showing an ongoing Neighbor Discovery (ND) process where the link-layer address has not yet been resolved.

Answer

The binding table is empty, indicating no ND activity.

Answer

The binding table shows all entries as reachable, indicating stable neighbor relationships.

Answer

The binding table is only for DHCPv6-learned addresses.

Question 2

A network engineer runs the following command to troubleshoot a Control Plane Policing (CoPP) issue:

R1# show bgp neighbors 10.1.1.2 advertised-routes

BGP table version is 10, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete

Network          Next Hop            Metric LocPrf Weight Path
*> 10.2.2.0/24      0.0.0.0                  0         32768 i

Total number of prefixes 1

What does this output indicate?

Accepted Answer

BGP is advertising routes correctly, and CoPP is not affecting outbound updates.. The output shows that BGP has one prefix (10.2.2.0/24) in the advertised-routes table for neighbor 10.1.1.2, with the next hop set to 0.0.0.0 (indicating a locally originated route). This confirms that BGP is successfully advertising routes outbound, and there is no evidence of CoPP dropping update packets. CoPP would only affect control plane traffic destined to the router itself, not outbound BGP updates, which are forwarded in the data plane.

Answer

BGP is not advertising routes due to CoPP dropping update packets.

Answer

BGP is receiving routes but not advertising them due to CoPP.

Answer

BGP session is down due to CoPP.

Question 3

An engineer is troubleshooting a BGP route selection issue. Router R1 receives two paths for prefix 10.0.0.0/8: one from eBGP peer R2 (AS 65002) with weight 0, local preference 100, and AS path 65002; and another from eBGP peer R3 (AS 65003) with weight 0, local preference 200, and AS path 65003 65004. R1's BGP table shows the path from R3 as the best route. The engineer wants the path from R2 to be preferred. What should the engineer do?

Accepted Answer

Configure a route-map on R1 to set weight 100 for routes from R2.. BGP path selection compares weight first. Setting weight 100 for routes from R2 makes the R2 path preferred over the R3 path (both have default weight 0). Option B setting local preference 250 would also make R2 preferred, but weight is compared earlier and is the more direct single-answer action. Option A sets local preference 150, still lower than R3's 200, so R3 remains preferred. Option C prepends AS numbers to the R3 path, but local preference 200 vs 100 is evaluated before AS path length, so R3 still wins unless weight is changed.

Answer

Configure a route-map on R1 to set local preference 150 for routes from R2.

Answer

Configure a route-map on R1 to set local preference 250 for routes from R2.

Answer

Configure a route-map on R1 to prepend two additional AS numbers to the AS path from R3.

Question 4

Which TWO conditions must be met for a BGP route to be considered the best path and installed in the routing table? (Choose TWO.)

Accepted Answer

The next hop must be reachable via the routing table.. Option B is correct because BGP performs a next-hop reachability check before a path can be considered valid and eligible for best-path selection; if the next hop cannot be resolved through the routing table (via a connected, static, or IGP-learned route), the path is not installed. Option C is correct because the BGP synchronization rule requires that a route learned from an IBGP peer must also be present in the IGP (or synchronization must be disabled) before it can be used; otherwise the route is not eligible for the routing table. Option A is not correct as a mandatory condition because AS_PATH length is only one step in the BGP best-path algorithm and is evaluated only after higher-priority checks such as weight, local preference, and locally originated routes. Option D is not correct because MED is a lower-priority tiebreaker and is compared only among paths from the same neighboring AS, not as a universal requirement. Option E is not correct because the lowest IGP metric to the next hop is also a later tiebreaker in the best-path algorithm, not a condition that must always be met for every BGP route.

Answer

The route must have the shortest AS_PATH length.

Answer

The route must have the lowest MED value among all paths.

Answer

The route must have the lowest IGP metric to the next hop.

Question 5

Which TWO statements about DHCPv6 stateless autoconfiguration (SLAAC) are true? (Choose TWO.)

Accepted Answer

SLAAC requires the 'A' flag to be set in Router Advertisements.. Option A is correct because in IPv6 stateless address autoconfiguration (SLAAC), hosts form their global unicast addresses by combining a Router Advertisement prefix with an interface identifier, and the prefix is only usable for autoconfiguration when the Autonomous ('A') flag is set in the RA prefix information option. Option B is correct because SLAAC only supplies addressing and default gateway information; additional parameters such as DNS server addresses (RDNSS) can be delivered via DHCPv6 in stateless mode, which is why the 'O' (Other-config) flag exists to tell hosts to query DHCPv6 for other configuration. Option C is wrong because the 'M' (Managed) flag indicates that addresses should be obtained via stateful DHCPv6, not SLAAC; SLAAC does not require it. Option D is wrong because 'ipv6 nd other-config-flag' sets the 'O' flag, not the 'M' flag (the 'M' flag is set with 'ipv6 nd managed-config-flag'). Option E is wrong because SLAAC is defined for IPv6 generally and works over any multicast-capable link type, not only Ethernet.

Answer

The 'M' flag in Router Advertisements must be set for SLAAC to operate.

Answer

The command 'ipv6 nd other-config-flag' sets the 'M' flag in Router Advertisements.

Answer

SLAAC can only be used on Ethernet interfaces.

Question 6

Which TWO configuration steps are required to implement IPv6 traffic filtering using a named ACL on a Cisco router? (Choose TWO.)

Accepted Answer

Create the ACL using the ipv6 access-list command.. The `ipv6 access-list` command is the standard Cisco IOS command used to create a named IPv6 ACL, which supports filtering based on IPv6 headers, extension headers, and upper-layer protocols. Option B is correct because the `ipv6 traffic-filter` command is the interface-level command that applies the named IPv6 ACL to filter inbound or outbound IPv6 traffic, analogous to `ip access-group` for IPv4.

Answer

Create the ACL using the access-list command.

Answer

Apply the ACL to the interface using the ip access-group command.

Answer

Apply the ACL to the interface using the ipv6 access-group command.

Question 7

Which TWO statements about Control Plane Policing (CoPP) are true? (Choose TWO.)

Accepted Answer

CoPP uses Modular QoS CLI (MQC) to define traffic classes and actions.. Control Plane Policing (CoPP) uses the Modular QoS CLI (MQC) to classify traffic into classes (e.g., routing protocol packets, management traffic) and apply actions such as rate-limiting or dropping. MQC provides a flexible, policy-based framework that allows you to define traffic classes with class maps and attach service policies to the control plane, rather than to physical interfaces.

Answer

CoPP is applied directly to physical interfaces to protect the control plane.

Answer

CoPP operates at Layer 2 to filter Ethernet frames before they reach the CPU.

Answer

CoPP replaces the need for access control lists (ACLs) on the device.

Question 8

A network engineer runs the following command to troubleshoot BFD with static routes:

R1# show ip route 10.8.8.0/24

Routing entry for 10.8.8.0/24
  Known via "static", distance 1, metric 0
  Routing Descriptor Blocks:
  * 10.9.9.2, via GigabitEthernet0/3
      Route metric is 0, traffic share count is 1
      BFD enabled, BFD state: UP

What does this output indicate?

Accepted Answer

Static route is installed with BFD tracking, and BFD session is UP.. The output shows that BFD is enabled for the static route and the BFD state is UP, meaning the next hop is reachable and BFD is providing fast failure detection.

Answer

Static route is not using BFD.

Answer

BFD state is DOWN, so the static route is removed.

Answer

Static route is using BFD only for IPv6.

Question 9

A network engineer runs the following command to troubleshoot an EIGRP issue:

R1# show ip eigrp topology 10.1.1.0/24 detail

IP-EIGRP (AS 100): Topology entry for 10.1.1.0/24
  State: Passive, Query origin flag: 1, 1 Successor(s), FD is 131072
  Routing Descriptor Blocks:
  10.1.2.2 (GigabitEthernet0/0), from 10.1.2.2, Send flag: 0x0
      Composite metric: (131072/130816), Route is Internal
      Vector metric:
        Minimum bandwidth is 10000 Kbit
        Total delay is 100 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 1
      Originating router: 10.1.2.2
      External data: Not advertised
      Protocol: EIGRP
      Route tag: 0
      Extended community: None

What does this output indicate?

Accepted Answer

The route is learned from a single neighbor and is in a stable state.. The output shows 'State: Passive', '1 Successor(s)', and 'FD is 131072' with a single routing descriptor block, indicating the route is stable and learned from one neighbor. 'Passive' in EIGRP means the route is not undergoing recomputation (not in Active state), and the presence of one successor means no load balancing. The route is internal (not redistributed), so it is a stable, single-path EIGRP route.

Answer

The route is an external EIGRP route redistributed from another protocol.

Answer

The route has multiple successors and is load-balanced.

Answer

The route is in Active state, meaning a query is in progress.

Question 10

A network engineer runs the following command to verify IPv6 uRPF drops:

R1# show ipv6 traffic | include verify
  0 verify source drops, 0 verify source suppressed drops

What does this output indicate?

Accepted Answer

No IPv6 packets have been dropped by uRPF checks.. The output shows '0 verify source drops' and '0 verify source suppressed drops', which are the counters for IPv6 unicast Reverse Path Forwarding (uRPF) drops. Since both counters are zero, no IPv6 packets have been dropped by uRPF checks. This does not necessarily mean uRPF is not configured; it simply indicates that no packets have failed the uRPF verification process.

Answer

uRPF is not configured on any interface.

Answer

uRPF is dropping all packets.

Answer

The router is not processing IPv6 traffic.

Question 11

Router R10 is configured with SNMP and EEM. An EEM applet is configured to send an SNMP trap when a specific syslog message is generated. The applet uses the 'action snmp-trap' command. However, the NMS receives no trap. The syslog message is generated and logged. The router's show snmp statistics shows TrapsSent: 0. What is the root cause?

Accepted Answer

The EEM applet is configured to send a trap, but the 'snmp-server host' command is missing, so the router has no destination for the trap.. The EEM applet uses the 'action snmp-trap' command to generate a trap, but without the 'snmp-server host' command, the router has no configured destination to send the trap to. The 'show snmp statistics' output showing TrapsSent: 0 confirms that the trap was generated internally but never transmitted, which is the classic symptom of a missing trap destination. The syslog message being logged and the applet triggering correctly rules out pattern-matching or registration issues.

Answer

The syslog message is not matching the EEM trigger pattern correctly.

Answer

The EEM applet is not registered due to a syntax error.

Answer

The SNMP community string is not configured with RW privileges.

Question 12

A network engineer runs the following command to troubleshoot a Route Redistribution issue:

R1# show ip route summary

And sees the following output:

Route Source    Networks    Subnets    Replicates    Overhead    Memory (bytes)
connected       2           0          0             0           512
static          1           0          0             0           256
ospf 1          5           0          0             0           1280
eigrp 100       3           0          0             0           768
bgp 65000       2           0          0             0           512
internal        1           0          0             0           256
Total           14          0          0             0           3584

What does this output indicate?

Accepted Answer

The router has 14 routes total, with OSPF contributing the most routes.. The 'show ip route summary' output lists the number of routes per source: connected (2), static (1), OSPF 1 (5), EIGRP 100 (3), BGP 65000 (2), and internal (1), totaling 14 routes. OSPF contributes the most routes (5), which matches option A exactly. The 'Subnets', 'Replicates', and 'Overhead' columns are all zero, indicating no classful subnetting anomalies or replication overhead in this table.

Answer

The router is not redistributing any routes because the counts are low.

Answer

BGP is the only protocol with external routes.

Answer

EIGRP has 3 routes, all of which are redistributed from OSPF.

Question 13

A network engineer runs the following command to troubleshoot an Administrative Distance issue:

R1# show ip route 172.16.0.0 255.255.0.0
Routing entry for 172.16.0.0/16
  Known via "ospf 1", distance 110, metric 20, type intra area
  Last update from 10.1.1.2 on GigabitEthernet0/0, 00:00:05 ago
  Routing Descriptor Blocks:
  * 10.1.1.2, from 2.2.2.2, 00:00:05 ago, via GigabitEthernet0/0
      Route metric is 20, traffic share count is 1

What does this output indicate?

Accepted Answer

The route is an OSPF intra-area route with administrative distance 110, which is the default for OSPF.. The output shows an OSPF intra-area route with administrative distance 110, which is the default for OSPF. The metric is 20, and the route is learned from neighbor 2.2.2.2.

Answer

The route is an OSPF external route with administrative distance 110.

Answer

The route has an administrative distance of 20 because it is an OSPF route.

Answer

The route is preferred over an EIGRP route with AD 90.

Question 14

A network engineer runs the following command to troubleshoot a Route Redistribution issue:

R1# show ip ospf database external

And sees the following output:

OSPF Router with ID (1.1.1.1) (Process ID 1)

Type-5 AS External Link States

LS age: 360
  Options: (No TOS-capability, DC)
  LS Type: AS External Link
  Link State ID: 192.168.10.0 (External Network Number )
  Advertising Router: 2.2.2.2
  LS Seq Number: 80000001
  Checksum: 0x1234
  Length: 36
  Network Mask: /24
       Metric Type: 2 (Larger than any link state path)
       TOS: 0
       Metric: 20
       Forward Address: 0.0.0.0
       External Route Tag: 100

What does this output indicate?

Accepted Answer

The route is redistributed into OSPF with a metric of 20 and a route tag of 100.. The output shows a Type-5 AS External LSA for 192.168.10.0/24, which means the route was redistributed into OSPF. The LSA has Metric: 20 and External Route Tag: 100, so the route is redistributed into OSPF with a metric of 20 and a route tag of 100. The forward address 0.0.0.0 indicates that the advertising ASBR is the next hop, not that the route is unreachable, and the Link State ID and network mask identify a specific /24 route, not the default route.

Answer

The route 192.168.10.0/24 is an OSPF internal route.

Answer

The forward address is 0.0.0.0, meaning the route is not reachable.

Answer

The route is a default route redistributed into OSPF.

Question 15

An MPLS network uses OSPF as the IGP. After redistributing BGP routes into OSPF, some MPLS forwarding failures occur for the redistributed prefixes. Router R1 config:
router ospf 1
 redistribute bgp 65001 subnets
!
router bgp 65001
 redistribute ospf 1

R1# show mpls ldp neighbor
Peer LDP Ident: 10.1.1.2:0, Local LDP Ident: 10.1.1.1:0
  TCP connection: 10.1.1.2.646 - 10.1.1.1.646
  State: Oper, Msg sent: 100, Msg rcvd: 80
  Downstream on demand

R2# show mpls ldp neighbor
Peer LDP Ident: 10.1.1.1:0, Local LDP Ident: 10.1.1.2:0
  TCP connection: 10.1.1.1.646 - 10.1.1.2.646
  State: Oper, Msg sent: 80, Msg rcvd: 100

What is the root cause?

Accepted Answer

The redistributed BGP routes have a higher administrative distance, causing them to not be installed in the routing table, breaking LDP label binding.. The show commands display an operational LDP session; however, the issue is that redistributed BGP routes become OSPF external routes with administrative distance 110. If the same prefix is also learned via eBGP (AD 20), the eBGP route is preferred and installed in the routing table. LDP requires the route to be in the routing table to assign a label. Since the OSPF external route is not installed, LDP does not assign a label for that prefix, which can cause MPLS forwarding failures for those prefixes. The LDP neighbor relationships themselves remain up, but label binding for the redistributed prefixes is broken. To fix, either adjust administrative distances (e.g., use `distance bgp 120 120 120` to make BGP less preferred) or use route filtering to avoid creating duplicate routes.

Answer

The LDP router-id is misconfigured, causing neighbor failure.

Answer

The OSPF process is missing the mpls ldp autoconfig command.

Answer

The BGP redistribution is missing the route-map to set the metric.

Question 16

In BFD multihop sessions, what is the default value for the TTL (or hop limit) in outgoing BFD Control packets on Cisco IOS-XE?

Accepted Answer

255. For BFD multihop sessions, Cisco IOS-XE defaults to a TTL of 255, as per RFC 5883, to ensure the packet can traverse multiple hops.

Answer

1

Answer

64

Answer

128

Question 17

A network engineer runs the following command to troubleshoot IPsec IKE phase 1:

R1# debug crypto isakmp
ISAKMP: (0:0:N/A:0) Starting aggressive mode exchange
ISAKMP: (0:0:N/A:0) processing SA payload
ISAKMP: (0:0:N/A:0) Checking ISAKMP transform 1 against priority 1 policy
ISAKMP: (0:0:N/A:0) encryption 3DES
ISAKMP: (0:0:N/A:0) hash SHA
ISAKMP: (0:0:N/A:0) group 2
ISAKMP: (0:0:N/A:0) auth pre-share
ISAKMP: (0:0:N/A:0) life type in seconds
ISAKMP: (0:0:N/A:0) life duration (basic) of 86400
ISAKMP: (0:0:N/A:0) atts are not acceptable

What does this output indicate?

Accepted Answer

IKE phase 1 fails due to transform set mismatch.. The debug output shows that the ISAKMP transform (3DES, SHA, group 2, pre-share) is being checked against the local policy, and the message 'atts are not acceptable' indicates a mismatch. This means the proposed transform set does not match any configured IKE policy on the responder, causing IKE phase 1 to fail. The failure is specifically due to a transform set mismatch, not authentication or lifetime issues.

Answer

IKE phase 1 is successful; the transform set is accepted.

Answer

IKE phase 1 fails due to authentication failure.

Answer

IKE phase 1 fails due to lifetime mismatch.

Question 18

Consider the following partial configuration on router R2:

interface GigabitEthernet0/0
 ip address 10.0.0.2 255.255.255.0
 ip ospf 1 area 0
!
interface GigabitEthernet0/1
 ip address 192.168.1.2 255.255.255.0
 ip ospf 1 area 0
!
router ospf 1
 router-id 2.2.2.2
 network 10.0.0.0 0.0.0.255 area 0
 network 192.168.1.0 0.0.0.255 area 0

What is the effect of this configuration?

Accepted Answer

OSPF will form adjacencies on both interfaces as intended; the configuration is redundant but functional.. The configuration redundantly enables OSPF on both interfaces via both the `ip ospf 1 area 0` interface-level command and the `network` statements under the OSPF process. This is valid and does not cause conflicts; OSPF will form adjacencies on both interfaces as intended. The router-id 2.2.2.2 is explicitly configured and will not be overridden by any loopback IP unless the router-id is not set or is removed.

Answer

OSPF will not form adjacencies because the interface and network commands conflict, causing OSPF to ignore the network statements.

Answer

OSPF will form adjacencies on both interfaces, but the router-id 2.2.2.2 will be overridden by the highest loopback IP.

Answer

OSPF will only form adjacency on GigabitEthernet0/1 because the network statement for 10.0.0.0 is incorrect.

Question 19

A network engineer runs the following command on Router R1:

R1# show bfd neighbors detail

IPv4 Sessions
NeighborAddr      LD/RD         Int        State         Holdown(mult)  Intf
10.1.1.2          1/3           Gi0/0      Up            3000(3)        Gi0/0

Session state is UP and not using echo function.
OurAddr: 10.1.1.1
Handle: 1
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 1000000, Received Multiplier: 3
Holddown (hits): 3000(0)
Rx Count: 100, Tx Count: 100

Based on this output, what is the BFD session's local discriminator?

Accepted Answer

The local discriminator is 1.. The local discriminator is the LD value shown in the output. In this case, it is 1.

Answer

The local discriminator is 3.

Answer

The local discriminator is 10.1.1.1.

Answer

The local discriminator is 10.1.1.2.

Question 20

A network engineer runs the following command on Router R1:

R1# show policy-map control-plane
  Control Plane

Service-policy input: CoPP
    class-map: MANAGEMENT (match-all)
      100 packets, 5000 bytes
      5 minute offered rate 0 bps
      police:
          8000 bps, 1500 limit, 1500 extended limit
        conformed 95 packets, 4750 bytes; action: transmit
        exceeded 5 packets, 250 bytes; action: drop
        conformed 0 bps, exceed 0 bps

class-map: ROUTING (match-all)
      200 packets, 10000 bytes
      5 minute offered rate 0 bps
      police:
          16000 bps, 3000 limit, 3000 extended limit
        conformed 200 packets, 10000 bytes; action: transmit
        exceeded 0 packets, 0 bytes; action: drop
        conformed 0 bps, exceed 0 bps

Based on this output, what is happening to traffic matching the MANAGEMENT class?

Accepted Answer

Some management traffic is being dropped because it exceeds the configured police rate.. The output shows that the MANAGEMENT class has a police rate of 8000 bps. Out of 100 packets, 5 packets were exceeded and dropped because they exceeded this configured rate. This confirms that some management traffic is being dropped due to policing, making option B correct.

Answer

All management traffic is being transmitted without any drops.

Answer

The management traffic is being rate-limited but no packets are dropped.

Answer

The police rate is too high, causing all traffic to be dropped.