300-410 Mock Exam 94 — 25 Questions

Question 1

Which DHCPv6 message is used by a server to respond to a SOLICIT with available configuration parameters?

Accepted Answer

ADVERTISE. In DHCPv6, when a client sends a SOLICIT message to discover available DHCPv6 servers, each server that can provide configuration parameters responds with an ADVERTISE message. This ADVERTISE message contains the server's preference and available configuration options, allowing the client to select the appropriate server. This process is defined in RFC 8415 and mirrors the DHCPv4 OFFER step.

Answer

REPLY

Answer

RECONFIGURE

Answer

INFORMATION-REQUEST

Question 2

A network engineer configures a DMVPN spoke with the following:

interface Tunnel0
 ip address 10.0.0.3 255.255.255.0
 ip nhrp network-id 100
 ip nhrp nhs 10.0.0.1
 tunnel source GigabitEthernet0/0
 tunnel mode gre multipoint
 ip nhrp map 10.0.0.1 192.168.1.1
 ip nhrp map multicast 192.168.1.1
!

What will happen when the spoke tries to send traffic to another spoke (10.0.0.4)?

Accepted Answer

The spoke will send traffic directly to 10.0.0.4 if it has a cached NHRP mapping, otherwise through the hub.. In DMVPN Phase 2/3, spokes initially send traffic through the hub. The hub then uses NHRP redirect (if configured) to tell the spoke to establish a direct tunnel. Without NHRP redirect on the hub, traffic always goes through the hub.

Answer

The spoke will always send traffic through the hub because of the static multicast map.

Answer

The spoke will send traffic directly to 10.0.0.4 without using the hub.

Answer

The spoke will drop the traffic because it does not have a route to 10.0.0.4.

Question 3

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

R1# debug ip ospf adj

And sees the following output:

*Mar  1 00:20:11.456: OSPF: Rcv pkt from 10.1.1.2, Serial0/0/0 : Mismatch Authentication type. Input packet specified type 0, we use type 1
*Mar  1 00:20:11.457: OSPF: Rcv pkt from 10.1.1.2, Serial0/0/0 : Mismatch Authentication type. Input packet specified type 0, we use type 1

What does this output indicate?

Accepted Answer

OSPF authentication is misconfigured; the neighbor is not using authentication while this router is.. The debug ip ospf adj output shows authentication type mismatch. The router expects type 1 (plaintext authentication) but the received packet has type 0 (no authentication). This prevents the OSPF adjacency from forming, which would affect route redistribution if OSPF is not learning routes.

Answer

OSPF adjacency is forming successfully with authentication.

Answer

OSPF is redistributing routes correctly but authentication is failing.

Answer

The OSPF process is using MD5 authentication and the neighbor is using plaintext.

Question 4

A network engineer runs the following command on Router R1:

R1# show event manager policy registered

No.  Type    Time Created            Name
1    applet  00:01:23 UTC Mar 1 2025  EIGRP_Neighbor_Down

R1# show ip eigrp neighbors

IP-EIGRP neighbors for process 100
H   Address                 Interface       Hold Uptime   SRTT   RTO  Q  Seq
                                            (sec)         (ms)       Cnt Num
0   192.168.1.2             Gi0/0            13 00:02:00   40   200  0  5

Based on this output, what is the most likely problem?

Accepted Answer

The EIGRP neighbor is up, and the EEM policy is ready to trigger if it goes down.. The EEM policy EIGRP_Neighbor_Down is registered, but the EIGRP neighbor is present with an uptime of 2 minutes. The correct answer is that the EEM policy has not been triggered because the neighbor is up; however, the policy is ready to act if the neighbor goes down.

Answer

The EIGRP neighbor is down.

Answer

The EEM policy has been triggered.

Answer

The EEM policy is misconfigured.

Question 5

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

R1# debug mpls ldp transport 10.1.1.1

Output:
*Mar  1 00:01:23.456: LDP: Sent hello to 10.1.1.1 (UDP 646) on GigabitEthernet0/0
*Mar  1 00:01:23.789: LDP: Received hello from 10.1.1.1 (UDP 646) on GigabitEthernet0/0
*Mar  1 00:01:24.012: LDP: Opened TCP connection to 10.1.1.1:646
*Mar  1 00:01:24.345: LDP: Initialization msg sent to 10.1.1.1
*Mar  1 00:01:24.678: LDP: Initialization msg received from 10.1.1.1
*Mar  1 00:01:25.001: LDP: Session with 10.1.1.1:0 (0x1234) is UP

What does this output indicate?

Accepted Answer

LDP session with neighbor 10.1.1.1 is successfully established. The debug output shows the LDP transport session establishment process. The sequence of events indicates a successful LDP session establishment: hello exchange, TCP connection, initialization messages, and session UP.

Answer

LDP discovery via multicast hello failed

Answer

TCP connection to 10.1.1.1 was refused

Answer

LDP session is stuck in initialization state

Question 6

A network engineer runs the following command to troubleshoot OSPFv3 adjacency:

R1# debug ipv6 ospf adj
*Mar  1 00:15:23.456: OSPFv3-1-IPv6 ADJ   Gi0/0: Rcv pkt from 2001:DB8:1::2, src 2001:DB8:1::2, area 0
*Mar  1 00:15:23.457: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: Our address 2001:DB8:1::1, his address 2001:DB8:1::2
*Mar  1 00:15:23.458: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: Neighbor is not DR, state 2WAY
*Mar  1 00:15:23.459: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: DR is 2001:DB8:1::2, BDR is 2001:DB8:1::1
*Mar  1 00:15:23.460: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: Build the Start DBD
*Mar  1 00:15:23.462: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: Master/Slave negotiation done
*Mar  1 00:15:23.464: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: Exchange done, loading started
*Mar  1 00:15:23.466: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: Loading done
*Mar  1 00:15:23.468: OSPFv3-1-IPv6 ADJ   Gi0/0: Nbr 2.2.2.2: Full

What does this output indicate?

Accepted Answer

The OSPFv3 adjacency formed successfully between routers with router IDs 1.1.1.1 and 2.2.2.2.. The debug output shows the successful OSPFv3 adjacency formation between two routers on interface Gi0/0.

Answer

The OSPFv3 adjacency failed due to area mismatch.

Answer

The adjacency is stuck in Exstart state due to interface MTU mismatch.

Answer

The router is the DR on this segment.

Question 7

A network engineer runs the following command to troubleshoot DMVPN with NHRP filtering:

R1# show ip nhrp detail
10.1.1.2/8 via 10.1.1.2, Tunnel0 created 00:10:00, expire 01:50:00
  Type: dynamic, Flags: authoritative unique registered
  NBMA address: 192.168.1.2
  (no-socket)
  (no-socket)

What does this output indicate?

Accepted Answer

The spoke at 10.1.1.2 has registered with the hub and is reachable via NBMA address 192.168.1.2.. The output shows an NHRP cache entry for a remote spoke (10.1.1.2) with NBMA address 192.168.1.2. The entry is dynamic and registered, indicating that the spoke has successfully registered with the hub.

Answer

The spoke is being filtered by an NHRP filter.

Answer

The NHRP entry is static and configured manually.

Answer

The spoke is not reachable because the NBMA address is incorrect.

Question 8

A network engineer runs the following command on Router R1:

R1# show ip route vrf RED 192.168.1.0

Routing entry for 192.168.1.0/24
  Known via "connected", distance 0, metric 0 (connected, via interface)
  Routing Descriptor Blocks:
  * directly connected, via GigabitEthernet0/2
      Route metric is 0, traffic share count is 1

Based on this output, which statement is correct?

Accepted Answer

The route is directly connected via GigabitEthernet0/2.. The output shows the route for 192.168.1.0/24 in VRF RED is a connected route via GigabitEthernet0/2. This is normal.

Answer

The route is learned via OSPF.

Answer

The route is a static route.

Answer

The route has a metric of 1.

Question 9

A network engineer runs the following command on Router R1:

R1# show dmvpn
Legend: Attrb -> S: Static, D: Dynamic, I: Incomplete
        N: NATed, L: Local, X: No Socket
        #Ent -> Number of NHRP entries with same NBMA peer
        NHS Status: E => Expecting Replies, R => Responding, W => Waiting
        UpDn Time -> Up or Down Time for a Tunnel
==========================================================================
Interface: Tunnel0, IPv4 NHRP Details
Type:Hub, NHRP Peers:2,

# Ent  Peer NBMA Addr Peer Tunnel Addr State  UpDn Tm Attrb
 ----- --------------- ---------------- ----- -------- -----
     1 10.1.1.2        172.16.0.2        UP    00:02:15 D
     1 10.1.1.3        172.16.0.3        UP    00:01:45 D

Based on this output, which statement is correct?

Accepted Answer

Router R1 is a hub with two dynamically registered spokes.. The show dmvpn command displays NHRP peers. The output shows two dynamic peers (D) with their NBMA and tunnel addresses. The hub has two spokes registered, both in UP state. The correct answer identifies the role and peer count.

Answer

Router R1 is a spoke with two hub peers.

Answer

The NHRP peers are static and not dynamic.

Answer

One spoke is experiencing a registration failure.

Question 10

Which BFD session state indicates that the session is fully established and operational?

Accepted Answer

Up. The Up state indicates that the BFD session is fully established, and both routers are exchanging control packets successfully.

Answer

Down

Answer

Init

Answer

AdminDown

Question 11

Examine the following EIGRP configuration on Router R6:

interface GigabitEthernet0/2
 ip hello-interval eigrp 100 15
 ip hold-time eigrp 100 45

What is the effect of these commands?

Accepted Answer

EIGRP will send hello packets every 15 seconds and wait 45 seconds before declaring a neighbor down.. The commands set a non-default hello interval of 15 seconds and a hold time of 45 seconds for EIGRP AS 100 on GigabitEthernet0/2. EIGRP uses the hello interval to determine how often it sends hello packets, and the hold time is the duration the router waits without receiving a hello before declaring the neighbor down. Option A correctly describes this behavior.

Answer

EIGRP will send hello packets every 45 seconds and wait 15 seconds.

Answer

EIGRP will use the default hello interval of 5 seconds and hold time of 15 seconds.

Answer

EIGRP will not form neighbor adjacencies because the hold time is not a multiple of the hello interval.

Question 12

In an extended IPv4 ACL, what is the default action if only a source and destination are specified without a protocol?

Accepted Answer

The command is rejected by the IOS parser.. In an extended IPv4 ACL, the protocol keyword is mandatory. If you omit it, the IOS parser rejects the command because it cannot determine which protocol to filter. The correct syntax requires a protocol (e.g., ip, tcp, udp) after the permit or deny keyword; without it, the parser returns an error.

Answer

The ACL matches all IP traffic.

Answer

The ACL matches only TCP traffic.

Answer

The ACL matches only UDP traffic.

Question 13

DMVPN phase 2 network: spoke-to-spoke tunnels fail. Router Spoke1 has: tunnel source GigabitEthernet0/0, tunnel mode gre multipoint, ip nhrp network-id 1, ip nhrp nhs 10.0.0.1. Router Spoke2 shows: show dmvpn includes Spoke1 in NHRP cache but no spoke-to-spoke tunnel. What is the root cause?

Accepted Answer

The hub is not configured with ip nhrp redirect, preventing shortcut initiation.. In a DMVPN Phase 2 network, spoke-to-spoke tunnels require the hub to send NHRP redirect messages to inform spokes of the shortcut path. Without the 'ip nhrp redirect' command on the hub, spokes will not attempt to build direct tunnels, even if they have each other's NHRP cache entries. This is the root cause because Spoke1 and Spoke2 can see each other in the NHRP cache but lack the trigger to initiate the spoke-to-spoke GRE tunnel.

Answer

Spoke1 and Spoke2 have different NHRP network IDs.

Answer

Spoke1 has a firewall blocking GRE traffic.

Answer

The tunnel mode should be point-to-point for spoke-to-spoke.

Question 14

Drag and drop the steps to troubleshoot EIGRP neighbor adjacency formation into the correct order, from first to last.

Accepted Answer

Verify Layer 1 and Layer 2 connectivity between routers. The correct order ensures that you first verify the physical and data link layer, then check IP connectivity, confirm EIGRP is enabled on the correct interfaces, verify the autonomous system number matches, and finally check for any passive interface configuration that might block adjacency.

Question 15

Which THREE commands are used to troubleshoot and verify device access control when using TACACS+ authentication on a Cisco IOS router? (Choose THREE.)

Accepted Answer

debug tacacs. The 'debug tacacs' command enables real-time logging of TACACS+ authentication, authorization, and accounting transactions, allowing you to observe the exact packets exchanged between the router and the TACACS+ server, including authentication failures or successes. Option B is correct because 'show tacacs' displays the current TACACS+ server statistics, including the number of successful and failed authentication attempts, server status, and the number of pending requests, which is essential for verifying connectivity and performance. Option C is correct because 'test aaa group tacacs+ ' directly tests the TACACS+ authentication process by sending a simulated authentication request to the configured TACACS+ server group, confirming whether the server is reachable and the credentials are valid.

Answer

debug radius authentication

Answer

show aaa method-list

Question 16

A network engineer runs the following command on Router R1:

R1# show ip ospf database external 10.1.1.0

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

Type-5 AS External Link States (Area 0)

LS age: 120
  Options: (No TOS-capability, DC)
  LS Type: AS External Link
  Link State ID: 10.1.1.0 (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

Based on this output, which statement is correct?

Accepted Answer

The route 10.1.1.0/24 is redistributed into OSPF from another protocol with a route-map setting the tag to 100.. The output shows an OSPF Type-5 external LSA for 10.1.1.0/24 with Metric Type 2 and Metric 20. The default metric for redistributed routes in OSPF is 20 for Type 2. The External Route Tag of 100 indicates a redistribution tag, often used for filtering or route-maps.

Answer

The route 10.1.1.0/24 is an OSPF inter-area route from area 0.

Answer

The metric of 20 indicates the route is redistributed with a default metric of 20, which is correct for Type 1 external routes.

Answer

The forward address of 0.0.0.0 indicates that the next hop is the advertising router 2.2.2.2.

Question 17

A network engineer runs the following command to troubleshoot a Device Access Control issue:

R1# show ip eigrp topology 10.10.10.0/24 all-links

P 10.10.10.0/24, 1 successors, FD is 1310720
        via 10.1.1.2 (1310720/1310720), GigabitEthernet0/0
        via 10.1.2.2 (1310720/1310720), GigabitEthernet0/1

What does this output indicate?

Accepted Answer

There are two equal-cost paths to 10.10.10.0/24, and EIGRP will load balance across them.. The output shows two EIGRP routes to 10.10.10.0/24 with identical Feasible Distances (FD) of 1310720, indicating equal-cost paths. EIGRP installs up to four equal-cost routes by default and performs per-destination load balancing across them, so both paths are active and used.

Answer

Only the first path via 10.1.1.2 is installed because the second path has a higher FD.

Answer

The path via 10.1.2.2 is a feasible successor but is not used because it has a higher RD.

Answer

The router has no route to 10.10.10.0/24 because the FD is the same as the RD.

Question 18

A network engineer runs the following command on Router R1:

R1# show ip route vrf CUSTOMER_A

Routing Table: CUSTOMER_A
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
B       10.10.10.0/24 [200/0] via 192.168.1.2, 00:10:00
B       10.20.20.0/24 [200/0] via 192.168.1.2, 00:10:00

R1# show ip bgp vpnv4 vrf CUSTOMER_A
BGP table version is 6, 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
Route Distinguisher: 100:1 (default for vrf CUSTOMER_A)
*> 10.10.10.0/24    192.168.1.2              0             0 65001 i
*> 10.20.20.0/24    192.168.1.2              0             0 65001 i
*> 10.30.30.0/24    192.168.1.2              0             0 65001 i

Based on this output, what is the likely issue?

Accepted Answer

A route-map is filtering the route 10.30.30.0/24 from the VRF routing table.. The VRF routing table shows only two routes, but the BGP table shows three routes for the VRF. This indicates that a route-map is filtering one of the routes from being installed in the routing table. The correct answer is that a route-map is filtering the route 10.30.30.0/24.

Answer

The VRF is not properly configured.

Answer

The BGP session is down.

Answer

The route distinguisher is misconfigured.

Question 19

An engineer is troubleshooting an EIGRP issue where a router is not learning a specific route from a neighbor, but other routes from the same neighbor are being learned. The engineer checks the EIGRP topology table and sees that the route is not present. The engineer also checks the neighbor's routing table and confirms that the route exists. What is the most likely cause?

Accepted Answer

A distribute-list in is applied on the local router that filters the specific route.. A distribute-list in applied on the local router can filter specific incoming routes from an EIGRP neighbor while allowing others. Since the neighbor has the route in its routing table and other routes from the same neighbor are learned, the most likely cause is an inbound filter that explicitly denies that particular prefix.

Answer

The neighbor is configured as a stub router.

Answer

The route is a summary route that is being suppressed by the 'summary-address' command.

Answer

The EIGRP metric for the route is too high, so it is not considered feasible.

Question 20

A network uses Control Plane Policing (CoPP) to protect the router. Router R1 has CoPP policy applied that rate-limits all traffic to 1 Mbps. R1 shows: 'show policy-map control-plane' indicates drops for EIGRP packets. R1's EIGRP neighbor R2 is flapping. What is the root cause?

Accepted Answer

The CoPP policy rate-limits EIGRP packets to 1 Mbps, but EIGRP hellos are small and frequent; the rate-limit may still drop them if the policer is not properly configured for burst.. EIGRP hello packets are small and sent frequently (every 5 seconds on most LAN interfaces by default). A CoPP policer that rate-limits all traffic to 1 Mbps without an adequate burst parameter will treat the burst of small hello packets as exceeding the committed burst (Bc), causing drops. These drops prevent EIGRP neighbor keepalives from reaching the control plane, leading to neighbor flapping. The root cause is not the total bandwidth but the policer's inability to accommodate the packet-per-second (PPS) burst of small EIGRP hellos.

Answer

R2 is sending too many EIGRP packets, exceeding the rate-limit.

Answer

R1 has an ACL that blocks EIGRP packets before they reach the control plane.

Answer

The CoPP policy is applied to the wrong interface.