300-410 Practice Exam 60 — 20 Questions

Question 1

After redistributing OSPF into EIGRP, an EIGRP router becomes stuck-in-active (SIA) for certain routes. Router R1 config:
router eigrp 100
 redistribute ospf 1 metric 10000 100 255 1 1500
!
router ospf 1
 redistribute eigrp 100 subnets

R1# show ip eigrp topology 10.0.0.0/8
IP-EIGRP (AS 100): Topology entry for 10.0.0.0/8
  State: Active, 0:01:15, Reply count: 0
  Originating router: 10.1.1.1
  Last sent query: 10.1.1.2

What is the root cause?

Accepted Answer

The redistributed OSPF route is a summary that causes EIGRP queries to go unanswered, leading to SIA.. The EIGRP route for 10.0.0.0/8 is in Active state, meaning it is waiting for replies from neighbors. The redistribution from OSPF may be injecting a summary route that causes a query to be sent to all neighbors, but one neighbor may not have a route back, causing the query to be unanswered. The fix is to ensure that the redistributed routes are not summarized or to use a stub router to limit query scope.

Answer

The EIGRP metric is too high, causing the route to be unreachable.

Answer

The OSPF redistribution is missing the subnets keyword, causing classful behavior.

Answer

The EIGRP AS number is mismatched between routers.

Question 2

Which TWO statements about EEM applet actions and their behavior are correct? (Choose TWO.)

Accepted Answer

The 'action cli command' can execute any EXEC mode command, including 'show' commands and 'ping'.. 'action cli command' can run any exec command. 'action syslog' sends a syslog message with facility local7 by default. 'action snmp-trap' requires an SNMP community. 'action mail' is not supported in EEM. 'action cli command' cannot run config commands directly without entering config mode.

Answer

The 'action snmp-trap' command can send an SNMP trap without any additional configuration if the device has an SNMP community set.

Answer

The 'action mail' command can be used to send an email notification from an EEM applet.

Answer

The 'action cli command' can be used to enter global configuration mode and execute configuration commands directly.

Question 3

A DMVPN network uses EIGRP as the routing protocol. After redistributing a static route into EIGRP on the hub, spoke-to-spoke tunnels fail to form. Hub configuration:
router eigrp 100
 redistribute static metric 10000 100 255 1 1500
!
ip route 10.0.0.0 255.0.0.0 Null0

Spoke1# show dmvpn
Interface: Tunnel0, IPv4 NHRP Details
Type:Spoke, NHRP Peers:2,
  # Ent  Peer NBMA Addr Peer Tunnel Addr State  UpDn Tm Attrb
  1     192.168.1.1     10.1.1.1        UP     00:01:00     D
  2     192.168.1.2     10.1.1.2        UP     00:00:30     D

What is the root cause?

Accepted Answer

The static Null0 route is redistributed, causing spokes to send traffic to the hub instead of directly to other spokes.. The static route to Null0 for 10.0.0.0/8 is redistributed into EIGRP, causing all spokes to learn a summary route pointing to Null0 on the hub. This blackholes traffic destined to other spokes, preventing dynamic spoke-to-spoke tunnel establishment. The fix is to use a more specific static route or filter the Null0 route from redistribution.

Answer

The EIGRP metric is too low, causing the route to be preferred over NHRP.

Answer

The DMVPN tunnel is misconfigured with mismatched authentication.

Answer

The redistribute static command is missing the route-map to set the next-hop.

Question 4

An engineer configures an EEM applet to monitor OSPF neighbor state changes using the event syslog pattern 'OSPF-5-ADJCHG'. The applet triggers a custom syslog message. The OSPF adjacency between two routers fails due to an MTU mismatch, but the EEM applet does not trigger. Which is the most likely explanation?

Accepted Answer

The OSPF-5-ADJCHG syslog message is not generated for MTU mismatch failures because the neighbor never reaches FULL state.. When an OSPF adjacency fails due to MTU mismatch, the neighbor state transitions from EXSTART to DOWN without generating the standard OSPF-5-ADJCHG syslog message. The adjacency never reaches FULL, so the state change from EXSTART to DOWN is logged as a different syslog pattern (OSPF-4-ERRRCV or OSPF-5-ADJCHG may not fire). EEM applets that rely on the exact pattern 'OSPF-5-ADJCHG' will not trigger because that message is only generated when the neighbor state changes from FULL to DOWN or vice versa.

Answer

The EEM applet has a typo in the event syslog pattern; it should match 'OSPF-5-ADJCHG' with a wildcard.

Answer

The EEM applet requires the 'event manager run' command to be enabled globally.

Answer

The MTU mismatch causes a routing loop that suppresses syslog generation.

Question 5

An MPLS network uses OSPF as the IGP. After redistributing BGP routes into OSPF, some LDP neighbors fail to establish. 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 redistribution of BGP into OSPF may cause OSPF routes to have a high metric or be external, which LDP may not use for label binding if the route is not in the routing table as an IGP route. LDP requires the route to be in the routing table with a next-hop that is reachable via an IGP. If the redistributed routes have a higher administrative distance or are not installed, LDP may fail to assign labels. The fix is to ensure that the IGP routes are preferred or use route-target filtering.

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 6

A network engineer configures an EEM applet to monitor EIGRP stuck-in-active (SIA) events using the event syslog pattern 'EIGRP-3-SIA'. The applet is designed to clear the EIGRP neighbor. The EIGRP network has a unidirectional link that causes a route to go active, but the EEM applet does not trigger. Which is the most likely explanation?

Accepted Answer

The EIGRP SIA syslog message is only generated when the SIA timer expires, but a unidirectional link may prevent the query from being sent, so the timer never starts.. EIGRP SIA events generate syslog messages only when the SIA timer expires (default 3 minutes). If the unidirectional link causes the route to go active but the query propagation is blocked or the neighbor is not reachable, the SIA timer may not start because the router does not receive a reply from the neighbor. In some cases, the route may remain active indefinitely without generating an SIA syslog if the query is not sent due to the unidirectional link. The EEM applet requires the specific 'EIGRP-3-SIA' syslog pattern, which is only generated when the SIA timer actually expires.

Answer

The EEM applet must use 'event eigrp' instead of 'event syslog' to catch EIGRP events.

Answer

The EIGRP process must be restarted for the EEM applet to take effect.

Answer

The unidirectional link causes a routing loop that suppresses syslog generation.

Question 7

A network administrator configures an ACL to filter routes during redistribution, but management traffic stops working. Router R1 config:
access-list 100 permit ip 10.0.0.0 0.255.255.255 any
!
router eigrp 100
 redistribute ospf 1 route-map FILTER
!
route-map FILTER permit 10
 match ip address 100

R1# show ip route 10.1.1.1
Routing entry for 10.1.1.1/32
  Known via "connected", distance 0, metric 0
  Redistributing via eigrp 100

What is the root cause?

Accepted Answer

The ACL implicit deny blocks all routes not matching 10.0.0.0/8, including management routes.. The ACL only permits 10.0.0.0/8, but the management traffic may use a different source or destination. The implicit deny at the end of the ACL blocks all other routes, including management prefixes. The fix is to add a permit statement for the management network or use a more specific ACL.

Answer

The route-map is missing the set metric command, causing routes to be unreachable.

Answer

The access-list is applied in the wrong direction.

Answer

The redistribute command is missing the subnets keyword.

Question 8

An engineer configures an EEM applet to react to BGP prefix changes using the event syslog pattern 'BGP-5-ADJCHANGE'. The applet sends a custom SNMP trap. The BGP session between two routers is established, but when a route is withdrawn due to next-hop-self requirement for iBGP, the EEM applet does not trigger. Which is the most likely explanation?

Accepted Answer

The BGP-5-ADJCHANGE syslog is only generated for session state changes, not for individual route updates.. The BGP-5-ADJCHANGE syslog message is generated only when the BGP session state changes (e.g., from Established to Idle or vice versa). It is not generated for individual prefix updates or withdrawals. When a route is withdrawn due to next-hop-self requirement, the BGP session remains established, so no ADJCHANGE event occurs. The EEM applet will not trigger because the syslog pattern does not match any generated message.

Answer

The EEM applet must be configured with 'event bgp' to monitor BGP prefix changes.

Answer

The next-hop-self requirement causes a BGP notification that generates a different syslog pattern.

Answer

The EEM applet requires the 'event manager directory' to be set for SNMP traps.

Question 9

A network engineer configures an EEM applet to monitor redistribution events using the event syslog pattern 'IP-4-ROUTING'. The applet is intended to log when a route is redistributed from OSPF into EIGRP. The redistribution is configured without a seed metric for EIGRP, and the route is not redistributed. The EEM applet does not trigger. Which is the most likely explanation?

Accepted Answer

Redistribution into EIGRP without a seed metric fails silently, and no syslog message is generated.. When redistributing routes into EIGRP without a seed metric, the redistribution fails silently—no syslog message is generated. The EIGRP process drops the redistributed route because the default metric is not set. The 'IP-4-ROUTING' syslog message is only generated when a routing table change occurs due to redistribution, but since the route is not installed, no syslog is produced. The EEM applet will not trigger because there is no matching syslog event.

Answer

The EEM applet must use 'event routing' to capture redistribution events.

Answer

The syslog pattern 'IP-4-ROUTING' is incorrect; it should be 'IP-5-ROUTING'.

Answer

The redistribution is blocked by route tagging, preventing the syslog.

Question 10

A network engineer configures CoPP to protect the control plane, but after redistributing routes, some legitimate routing updates are dropped. Router R1 config:
control-plane
 service-policy input COPP
!
class-map match-all ROUTING
 match access-group name ROUTING
!
policy-map COPP
 class ROUTING
  police 100000 15000 15000 conform-action transmit exceed-action drop
!
access-list ROUTING permit tcp any any eq bgp
access-list ROUTING permit udp any any eq 520
access-list ROUTING permit ospf any any

R1# show policy-map control-plane input
  Class-map: ROUTING (match-all)
    100 packets, 10000 bytes
    5 minute offered rate 0 bps
    drop rate 0 bps
  Match: access-group name ROUTING
  police:
      cir 100000 bps, bc 15000 bytes, be 15000 bytes
    conformed 90 packets, 9000 bytes; actions: transmit
    exceeded 10 packets, 1000 bytes; actions: drop

What is the root cause?

Accepted Answer

The CoPP police rate is too low for the volume of routing updates during redistribution, causing drops.. The CoPP policy is policing routing protocol traffic at 100 kbps, which may be insufficient during redistribution bursts. The exceeded drops indicate that some packets are being dropped, likely due to the burst size being too small. The fix is to increase the police rate or burst size to accommodate the redistribution traffic.

Answer

The access-list is missing EIGRP protocol, causing EIGRP packets to be dropped.

Answer

The class-map is match-all, which requires all conditions to match, but only one ACL is present.

Answer

The policy-map is applied to the input of the control-plane, but redistribution uses output.

Question 11

An engineer configures an EEM applet to monitor DMVPN tunnel events using the event syslog pattern 'NHRP-3-REGISTRATION'. The applet is supposed to send an email when a spoke registers with the NHS. The DMVPN network uses Phase 2 with spoke-to-spoke tunnels. A spoke registers successfully, but the EEM applet does not trigger. Which is the most likely explanation?

Accepted Answer

Successful NHRP registration generates a syslog message with severity 6 (informational), not severity 3 (error).. In DMVPN Phase 2, spoke-to-spoke tunnels are established dynamically, but the NHRP registration event generates a syslog message only when the spoke registers with the NHS. However, the syslog pattern 'NHRP-3-REGISTRATION' is for error-level messages, while successful registration generates an informational message (NHRP-6-REGISTRATION). The EEM applet is looking for severity level 3, but the actual syslog is severity level 6, so the pattern does not match.

Answer

The EEM applet must be configured with 'event nhrp' to capture NHRP events.

Answer

The DMVPN Phase 2 does not generate syslog messages for spoke registration.

Answer

The NHS must be configured with 'ip nhrp registration no-syslog' to suppress messages.

Question 12

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

R1# debug ip routing

And sees the following output:

*Mar  1 00:12:34.567: RT: add 192.168.10.0/24 via 10.1.1.2, ospf metric [110/20]
*Mar  1 00:12:34.568: RT: add 192.168.10.0/24 via 10.2.2.2, eigrp metric [90/156160]
*Mar  1 00:12:34.569: RT: better route for 192.168.10.0/24 via 10.1.1.2, ospf metric [110/20]
*Mar  1 00:12:34.570: RT: add 192.168.10.0/24 to rib via 10.1.1.2, ospf metric [110/20]

What does this output indicate?

Accepted Answer

OSPF route is being installed in the routing table because the EIGRP route may have been withdrawn or not learned.. The debug ip routing output shows the routing table process comparing routes from different sources. OSPF has administrative distance 110 and EIGRP has 90, so EIGRP is preferred by default. However, the output shows OSPF being chosen, indicating that the EIGRP route might have been removed or the OSPF route is being redistributed with a lower distance or the EIGRP route is not installed due to other reasons.

Answer

OSPF route is preferred over EIGRP because OSPF has a lower metric.

Answer

EIGRP route is preferred because it has a lower administrative distance.

Answer

Both routes are installed in the routing table for load balancing.

Question 13

When redistributing OSPF into EIGRP, which EIGRP metric components are used to calculate the default metric?

Accepted Answer

No default metric is assigned; redistribution fails unless a metric is configured.. EIGRP requires all five K-values (bandwidth, delay, reliability, load, MTU) for metric calculation, but by default, only bandwidth and delay are used; the default metric for redistribution is not automatically derived and must be explicitly set.

Answer

Bandwidth and delay only

Answer

Bandwidth, delay, reliability, load, and MTU

Answer

The OSPF cost is converted to an EIGRP metric using a default formula.

Question 14

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

R1# debug eigrp packets

And sees the following output:

*Mar  1 00:15:22.123: EIGRP: Received UPDATE on Serial0/0/0 nbr 10.1.1.2
*Mar  1 00:15:22.124:   AS 100, Flags 0x1, Seq 45/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar  1 00:15:22.125:   Ext: 192.168.10.0/255.255.255.0, metric 156160, tag 0
*Mar  1 00:15:22.126: EIGRP: Enqueueing UPDATE on Serial0/0/0 nbr 10.1.1.2 iidbQ un/rely 0/1 peerQ un/rely 0/0 serno 12-12
*Mar  1 00:15:22.127: EIGRP: Sending UPDATE on Serial0/0/0 nbr 10.1.1.2, retry 0, R=1
*Mar  1 00:15:22.128:   Ext: 10.2.2.0/255.255.255.0, metric 128256, tag 0

What does this output indicate?

Accepted Answer

R1 is receiving an EIGRP update and sending an update in response, which is normal EIGRP behavior.. The debug eigrp packets output shows EIGRP update packets being exchanged. R1 receives an update for 192.168.10.0/24 from neighbor 10.1.1.2 and then sends an update for 10.2.2.0/24. This indicates normal EIGRP operation; no redistribution issue is apparent from this output.

Answer

EIGRP is redistributing routes from another protocol into EIGRP, as indicated by the tag 0.

Answer

R1 is learning 192.168.10.0/24 via EIGRP and advertising 10.2.2.0/24 back to the same neighbor, which could indicate a routing loop.

Answer

The metric of 156160 indicates that the route 192.168.10.0/24 is redistributed from OSPF.

Question 15

An engineer redistributes OSPF routes into EIGRP. The OSPF routes have a metric of 20. After redistribution, the EIGRP topology table shows the routes but they are not installed in the routing table. The 'show ip eigrp topology' shows the route in active state. Which is the most likely explanation?

Accepted Answer

The EIGRP neighbor is stuck-in-active because a query was sent but no reply was received due to a unidirectional link.. When redistributing into EIGRP, a seed metric must be specified. If not, the routes are redistributed with an infinite metric (e.g., 4294967295) and are not installed. However, the question says the route is in active state, which indicates a query is pending. This is an edge case where the route is redistributed with a valid metric but the EIGRP process is stuck-in-active due to a unidirectional link or a neighbor not replying to queries.

Answer

The 'default-metric' command was not configured, so the routes are redistributed with an infinite metric.

Answer

The OSPF routes are external type 2, which are not redistributed by default.

Answer

The 'route-map' used for redistribution has a 'match ip address' that does not match the OSPF routes.

Question 16

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

R1# show ip eigrp topology 192.168.10.0/24

And sees the following output:

IP-EIGRP (AS 100): Topology entry for 192.168.10.0/24
  State: Passive, Originating, 1 successors, FD is 128256
  Routing Descriptor Blocks:
  0.0.0.0 (Null0), from 0.0.0.0, Send flag 0x0
      Composite metric is (128256/0), Route is Internal
      Vector metric:
        Minimum bandwidth is 100000 Kbit
        Total delay is 5000 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 0

What does this output indicate?

Accepted Answer

The route is redistributed into EIGRP from another protocol, such as OSPF or BGP.. The show ip eigrp topology command shows a route that is in Passive state and marked as Originating, with the next hop as 0.0.0.0 (Null0). This indicates that the route is a summary route or a redistributed route that is being originated by this router. The metric 128256 and hop count 0 suggest it is a directly connected or redistributed route.

Answer

The route 192.168.10.0/24 is learned from an EIGRP neighbor.

Answer

The route is a summary route configured on this router.

Answer

The route is a connected interface that is advertised in EIGRP.

Question 17

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 18

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 show ip ospf database external output shows a Type 5 LSA for 192.168.10.0/24, with metric type 2 and metric 20, and external route tag 100. This indicates that the route is redistributed into OSPF from another protocol (likely EIGRP or BGP) by router 2.2.2.2. The tag 100 can be used for filtering.

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 19

A network engineer runs the following command on Router R1:

R1# show ip policy
Interface     Route-map
GigabitEthernet0/0      PBR-TEST

R1# show route-map PBR-TEST
route-map PBR-TEST, permit, sequence 10
  Match clauses:
    ip address (access-lists): 110
  Set clauses:
    ip next-hop 192.168.100.1
  Policy routing matches: 0 packets, 0 bytes

R1# show access-lists 110
Extended IP access list 110
    10 permit tcp 10.0.0.0 0.255.255.255 any eq 80
    20 permit tcp 10.0.0.0 0.255.255.255 any eq 443

R1# show ip route 192.168.100.1
Routing entry for 192.168.100.1/32
  Known via "ospf 1", distance 110, metric 20
  Last update from 10.1.1.2 on GigabitEthernet0/1

Based on this output, what is the most likely reason for zero policy routing matches?

Accepted Answer

The access list 110 is not matching any traffic arriving on GigabitEthernet0/0.. The access list 110 matches TCP traffic from 10.0.0.0/8 to any destination on ports 80 and 443. The route map is applied to GigabitEthernet0/0, but traffic arriving on that interface may not match these conditions. The next-hop is reachable, so the issue is likely that no traffic matching ACL 110 is entering GigabitEthernet0/0.

Answer

The next-hop 192.168.100.1 is not reachable.

Answer

The route map sequence number is too high.

Answer

The route map needs to be applied globally.

Question 20

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

R1# debug ip bgp updates

And sees the following output:

*Mar  1 00:25:44.789: BGP(0): 10.1.1.2 UPDATE out about 192.168.10.0/24, NEXT_HOP 10.1.1.1, LOCAL_PREF 100, MED 0, origin i, path 65000 65001
*Mar  1 00:25:44.790: BGP(0): 10.1.1.2 UPDATE run, update sent
*Mar  1 00:25:44.791: BGP(0): 10.1.1.2 UPDATE in about 10.2.2.0/24, NEXT_HOP 10.1.1.2, LOCAL_PREF 100, MED 0, origin i, path 65002

What does this output indicate?

Accepted Answer

R1 is advertising 192.168.10.0/24 to neighbor 10.1.1.2 and learning 10.2.2.0/24 from the same neighbor.. The debug ip bgp updates output shows BGP updates being sent and received. R1 sends an update for 192.168.10.0/24 with AS path 65000 65001 and receives an update for 10.2.2.0/24 with AS path 65002. This indicates BGP is exchanging routes, but if redistribution is expected, the AS path may indicate the route origin.

Answer

BGP is redistributing routes from OSPF into BGP, as shown by the AS path.

Answer

The route 192.168.10.0/24 is being filtered due to AS path length.

Answer

BGP is not receiving any routes because of a redistribution issue.