300-410 Practice Test 20 — 15 Questions

Question 1

What is the default behavior of EEM when a policy encounters a runtime error?

Accepted Answer

EEM logs the error and continues with the next policy.. By default, EEM logs the error via syslog and stops executing the policy; it does not retry.

Answer

EEM automatically retries the policy up to three times.

Answer

EEM reloads the device to clear the error.

Answer

EEM ignores the error and proceeds with the next action in the same policy.

Question 2

When redistributing routes from EIGRP into OSPF, what is the default OSPF metric assigned to redistributed routes if no metric is specified?

Accepted Answer

20. Cisco IOS assigns a default metric of 20 to redistributed routes from other protocols into OSPF if no metric is explicitly configured. This is defined in Cisco's implementation.

Answer

1

Answer

10

Answer

0

Question 3

Which TWO statements about EEM applet configuration and execution are correct? (Choose TWO.)

Accepted Answer

An EEM applet can be triggered by multiple event types if the 'event' statements are configured under the same applet using the 'multiple' keyword.. EEM applets can be configured with multiple events using the 'multiple' keyword. The 'action info type routername' command retrieves the router hostname. The 'event cli' pattern is case-sensitive by default. The 'event timer countdown' does not support the 'time' keyword; it uses 'countdown-time'. The 'action string' does not support 'trim' as a subcommand.

Answer

The 'event cli' pattern matching is case-insensitive by default.

Answer

The 'event timer countdown' command uses the 'time' keyword to specify the duration in seconds.

Answer

The 'action string' command can be used to trim leading and trailing whitespace from a variable using the 'trim' subcommand.

Question 4

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 5

An engineer configures a BGP route reflector with two clients. One client advertises a prefix to the route reflector. The route reflector reflects the prefix to the other client, but the second client does not install it in its routing table. The second client has a lower administrative distance for the same prefix from another protocol. Which is the most likely explanation?

Accepted Answer

The second client has a route from another protocol (e.g., OSPF) with a lower administrative distance for the same prefix, so BGP route is not installed.. A router installs only the best route for a given prefix based on administrative distance (AD) when multiple routing protocols provide routes. BGP has a default AD of 20 for eBGP and 200 for iBGP, while OSPF has an AD of 110. Since OSPF has a lower AD, the OSPF route is preferred and installed in the routing table, causing the BGP-learned prefix to be ignored even though it was successfully reflected.

Answer

The route reflector does not set the next-hop-self, so the next-hop is unreachable from the second client.

Answer

The route reflector is not configured as a client on the second router.

Answer

The BGP synchronization rule is enabled and the prefix is not in the IGP.

Question 6

Which statement correctly describes the behavior of the 'default-information originate' command in OSPF?

Accepted Answer

It injects a default route as a Type 5 LSA only if a default route exists in the routing table.. The 'default-information originate' command in OSPF generates a default route (0.0.0.0/0) as a Type 5 LSA, but only if a default route exists in the routing table, unless the 'always' keyword is used.

Answer

It always injects a default route into OSPF regardless of the routing table.

Answer

It injects a default route as a Type 3 LSA.

Answer

It injects a default route as a Type 7 LSA in all OSPF areas.

Question 7

What is the default metric value assigned to redistributed routes into IS-IS when no metric is specified?

Accepted Answer

0. By default, Cisco IOS assigns a metric of 0 to routes redistributed into IS-IS, which can cause suboptimal routing if not modified.

Answer

10

Answer

20

Answer

63

Question 8

An MPLS network with routers R1, R2, and R3 is experiencing label distribution failures. R1 and R2 are LDP neighbors, but R2 shows: 'show mpls ldp neighbor' shows R1 in state OPERATIONAL, but 'show mpls forwarding-table' shows no labels for prefixes from R3. R3 is connected to R2 via a different interface. R2 configuration: mpls ip on both interfaces. R1 shows: 'show mpls ldp bindings' includes prefixes from R3. What is the root cause?

Accepted Answer

The interface between R2 and R3 is missing the 'mpls ip' command, preventing LDP from establishing a session and exchanging labels.. The root cause is that the interface between R2 and R3 is missing the 'mpls ip' command. Without this command on the link, LDP cannot form a session or exchange label bindings across that interface. Since R2 and R3 are not LDP neighbors, R2 never receives labels for prefixes from R3, even though R1 has learned those bindings via its own LDP session with R2.

Answer

The LDP router ID on R2 is set to a loopback that is not reachable from R3.

Answer

R3 is using a different label distribution protocol, such as TDP.

Answer

The MPLS label range on R2 is exhausted, preventing new label bindings.

Question 9

When redistributing routes into OSPF, which OSPF metric value is assigned by default if none is specified?

Accepted Answer

20. Cisco IOS assigns a default metric of 20 to redistributed routes into OSPF, except for BGP routes which default to 1.

Answer

1

Answer

10

Answer

100

Question 10

What is the default route distinguisher (RD) format when using the 'ip vrf' command without specifying an RD?

Accepted Answer

The VRF will not be created until an RD is configured.. The RD is mandatory when creating a VRF. If not specified, the VRF will not be created. There is no default RD.

Answer

The RD defaults to 0:0.

Answer

The RD is automatically derived from the router ID.

Answer

The RD defaults to the ASN:1 format.

Question 11

Which TWO commands would a network engineer use to verify the operation of Policy-Based Routing (PBR) on a Cisco IOS router? (Choose TWO.)

Accepted Answer

show route-map. The 'show route-map' command displays the configured route-map statements and their match/set conditions. The 'show ip policy' command lists interfaces with PBR applied and the associated route-map. 'show ip route' does not show PBR policy details. 'debug ip policy' is a debug command, not a verification show command. 'show access-lists' only shows ACLs, not PBR-specific information.

Answer

show ip route

Answer

debug ip policy

Answer

show access-lists

Question 12

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

Accepted Answer

Check routing table for redistributed prefixes. Verification of redistribution starts with checking the routing table for redistributed routes, then examining the specific protocol database, followed by verifying the redistribution configuration, then checking for administrative distance issues, and finally using traceroute to validate the path. This order confirms routes are present, correctly sourced, and reachable.

Question 13

An experienced network engineer configures mutual redistribution between OSPF and EIGRP on a router. Both protocols have routes to the same prefix, but after redistribution, a routing loop occurs. The engineer did not use route tagging. Which is the most likely explanation?

Accepted Answer

The redistribute command without route-map or tag allows routes to be re-advertised back into the source protocol, creating a loop.. Without route tagging, redistributed routes are re-injected back into the original protocol, causing a feedback loop. Administrative distance comparison (OSPF 110 vs EIGRP 90/170) can cause suboptimal path selection, but the loop is primarily due to lack of tagging and filtering.

Answer

The seed metric for EIGRP was not configured, causing routes to be rejected.

Answer

OSPF has a lower administrative distance than EIGRP, so OSPF routes are always preferred.

Answer

EIGRP stub configuration on the redistributing router prevents routes from being advertised.

Question 14

In IPv6 First Hop Security, what is the purpose of the 'device-role' command in a DHCP guard policy?

Accepted Answer

It specifies whether the interface is a server, client, or relay for DHCP filtering.. The 'device-role' command in a DHCP guard policy specifies the role of the interface as either a DHCP server, client, or relay. This allows the switch to filter DHCP messages based on the expected role, blocking unauthorized DHCP server messages on interfaces that should only have clients or relays. It is a key component of IPv6 First Hop Security to prevent rogue DHCPv6 servers.

Answer

It sets the trust level for ND inspection.

Answer

It defines the VLAN membership for the interface.

Answer

It enables IPv6 routing on the interface.

Question 15

An engineer configures IPsec site-to-site VPN between two routers. The tunnel establishes, but traffic does not pass. The 'show crypto ipsec sa' shows packets being encapsulated but no decapsulation. Which is the most likely explanation?

Accepted Answer

The crypto ACL on the local router permits traffic, but the remote router's crypto ACL does not match the decrypted traffic.. If packets are encapsulated but not decapsulated, the remote peer is likely not receiving the encrypted traffic or cannot decrypt it. A common edge case is that the interesting traffic ACL on one side does not match the actual traffic (e.g., mismatched source/destination), causing the remote peer to receive packets that do not match its crypto map ACL, so it drops them.

Answer

The transform set on the remote peer is missing ESP encryption.

Answer

The IKE policy uses aggressive mode, which is incompatible with main mode.

Answer

The 'crypto isakmp key' command uses a different pre-shared key on each side.