300-410 Cisco Implementing Cisco Enterprise Advanced Routing and Services (300-410 ENARSI) Free Practice Exam Questions (2025 Updated)

SNMP notifications can be sent as traps or inform requests. Traps are unreliable because the receiver does not send acknowledgments when this device receives traps.”Send reliable and encrypted notifications for any events” so it is SNMP notifications. For encryption we need to configure “priv”.

Graphical user interface, application Description automatically generated

If a router is configured to get the time from a Network Time Protocol (NTP) server, the times in the router’s log entries may be different from the time on the systemclock if the [localtime] option is not in the service timestamps log command. To solve this issue, add the [localtime] option to the service timestamps log command. Thetimes should now be synchronized between the system clock and the log message timestamps.

The IPv6 Router Advertisement Guard feature provides support for allowing the network administrator to block or reject unwanted or rogue router advertisement guard messages that arrive at the network device platform. Router Advertisements are used by devices to announce themselves on the link. The IPv6 Router Advertisement Guard feature analyzes these router advertisements and filters out router advertisements that are sent by unauthorized devices.

Certain switch platforms can already implement some level of rogue RA filtering by the administrator configuring Access Control Lists (ACLs) that block RA ICMP messages that might be inbound on “user” ports.

In fact in this question both answer A and answer C are correct but we believe answer A is the

better choice as it only allows PC-2 to telnet to terminal server. All other hosts are refused to

telnet to terminal server via sequence 20.

The configuration on NY router is good for OSPF authentication. So we must enable OSPF

authentication on LA router with the following commands:

router ospf 1

area 0 authentication message-digest

interface E0/0

ip ospf message-digest-key 1 md5 Cisco123

To configure Spoke to Spoke communication we can configure DMVPN Phase II or Phase III. But in Phase II, the first few packets would go through Hub. In order tototally ignore the hub, we have to use DMVPN Phase III:

DMVPN Phase III is same as Phase 2 but removes some restrictions and complexities of Phase 2. Also allows greater variety of DMVPN network designs we use:+ ip nhrp redirect in hub: tells the initiator spoke to look for a better path to the destination spoke than through the Hub. Upon receiving the NHRP redirect message thespokes communicate with each other over the hub and they have their NHRP replies for the NHRP Resolution Requests that they sent out.+ ip nhrp shortcut in spokes: overwrite the CEF table on the spoke. It basically overrides the next-hop value for a remote spoke network from the default initial hubtunnel IP address to the NHRP resolved remote spoke tunnel IP address)

After redistribution, R3 learns about network 10.1.1.0/24 via two paths:+ Internal BGP (IBGP): advertised from R4 with AD of 200 (and metric of 0)+ OSPF: advertised from R1 with AD of 110 (O E2) (and metric of 20)Therefore R3 will choose the path with the lower AD via OSPF

But this is a looped path which is received from R3 -> R2 -> R1 -> R3. So when the advertised route from R4 is expired, the looped path is also expired soon and R3 willreinstall the main path from R4. This is the cause of intermittent connectivity.In order to solve this issue, we can lower the AD of iBGP to a value which is lower than 110 so that it is preferred over OSPF-advertised route.

https://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/109597-csr-chained-certificates-wlc-00.html#anc12

Overview of the IPv6 First-Hop Security Binding Table

A database table of IPv6 neighbors connected to the device is created from information sources such as NDP snooping. This database, or binding table, is used by variousIPv6 guard features to validate the link-layer address (LLA), the IPv4 or IPv6 address, and the prefix binding of the neighbors to prevent spoofing and redirect attacks.

IPv6 First-Hop Security Binding Table Recovery MechanismThe IPv6 first-hop security binding table recovery mechanism enables the binding table to recover in the event of a device reboot.

Unmonitored: Unmonitored devices are devices for which Assurance did not receive any

telemetry data during the specified time range.

+ allows an LSR to remove the label before forwarding the packet: penultimate hop popping

+ accepts unlabeled packets and imposes labels: label edge router

+ group of packets that are forwarded in the same manner: forwarding equivalence class

+ receives labeled packets and swaps labels: label switch router

Explanation

A label edge router (LER, also known as edge LSR) is a router that operates at the edge of an MPLS network and acts as the entry and exit points for the network. LERspush an MPLS label onto an incoming packet and pop it off an outgoing packet.

A forwarding equivalence class (FEC) is a term

The Destination Guard feature helps in minimizing denial-of-service (DoS) attacks. It performs address resolutions only for those addresses that are active on the link,and requires the FHS binding table to be populated with the help of the IPv6 snooping feature.The feature enables the filtering of IPv6 traffic based on the destinationaddress, and blocks the NDP resolution for destination addresses that are not found in the binding table. By default, the policy drops traffic coming for an unknowndestination.

MPLS Layer-3 VPNs provide IP connectivity among CE sites* MPLS VPNs enable full-mesh, hub-andspoke, and hybrid IP connectivity* CE sites connect to the MPLS network via IP peering across PE-CE links* MPLS Layer-3 VPNs are implemented via VRFs on PE edge nodes* VRFs providing customer routing and forwarding segmentation* BGP used for signaling customer VPN (VPNv4) routes between PE nodes* To ensure traffic separation, customer traffic is encapsulated in an additional VPN label when forwarded in MPLS network* Key applications are layer-3 business VPN services, enterprise network segmentation, and segmented layer-3 Data Center access

From the output, we learned that R1 was trying to establish BGP neighbor relationship with R3 but failed. Both of them were using physical interface to establish neighbor relationship so wedon’t need the “… ebgp-multihop” command here. The only reasonable answer is R3 has not been configured to activate BGP neighbor relationship with R1.

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/5_x/nx-os/mpls/configuration/guide/mpls_cg/mp_mpls_overview.pdf

Follow these guidelines when configuring the switch as an SSH server or SSH client:

+ An RSA key pair generated by a SSHv1 server can be used by an SSHv2 server, and the reverse.+ If the SSH server is running on a stack master and the stack master fails, the new stack master uses the RSA key pair generated by the previous stack master

+ If you get CLI error messages after entering the crypto key generate rsa global configuration command, an RSA key pair has not been generated. Reconfigure thehostname and domain, and then enter the crypto key generate rsa command.+ When generating the RSA key pair, the message No host name specified might appear. If it does, you must configure a hostname by using the hostname globalconfiguration command.+ When generating the RSA key pair, the message No domain specified might appear. If it does, you must configure an IP domain name by using the ip domain-nameglobal configuration command.+ When configuring the local authentication and authorization authentication method, make sure that AAA is disabled on the console.

The set ip default next-hop command verifies the existence of the destination IP address in the routing table, and…+ if the destination IP address exists, the command does not policy route the packet, but forwards the packet based on the routing table.+ if the destination IP address does not exist, the command policy routes the packet by sending it to the specified next hop.

In this topology, Chicago router (Hub) will receive advertisements from Los Angeles (Spoke1) router on its tunnel interface. The problem here is that it also has a connection with New York (Spoke2) on that same tunnel interface. If we don’t disable EIGRP split-horizon, then the Hub will not relay routes from Spoke1 to Spoke2 and the other way around. That is because it received those routes on interface Tunnel1 and therefore it cannot advertise back out that same interface (splithorizon rule). Therefore we must disable split-horizon on the Hub router to make sure the Spokes know about each other.