Pass the Cisco CCNP Enterprise 300-420 Questions and answers with Dumpstech

The valid get-config reply must show OSPF process ID 400 with network 192.168.128.128/25 enabled for Area 0. A /25 prefix has a block size of 128 addresses, so 192.168.128.128/25 is a valid network boundary and covers addresses from 192.168.128.128 through 192.168.128.255. Any reply that shows the wrong OSPF process, an incorrect network boundary, the wrong prefix length or wildcard equivalent, or a nonzero area does not verify the requested model set. In Cisco IOS XE model-driven configuration, the readback has to match the schema path and values used by the model, not simply produce an approximate CLI interpretation. Option B is the reply that confirms the intended OSPF object. This verification method is important because YANG automation can fail silently in operational workflows when the payload is syntactically valid but targets the wrong container or key. A get-config verification step confirms the running datastore contains the exact OSPF process and area membership required by the design. Reference topics: YANG OSPF configuration, NETCONF get-config, prefix validation, IOS XE native models.

MSDP is the correct solution because the question explicitly references RFC 3618, which defines the Multicast Source Discovery Protocol. The design has separate PIM Sparse Mode multicast domains, with RP functions already configured on edge routers in each autonomous system. Cisco explains that MSDP allows rendezvous points in different PIM-SM domains to discover active multicast sources outside their local domain. When a source becomes active, the local RP can advertise source-active information to MSDP peers, allowing receivers in another domain to learn and join the stream. PIM-SSM is not correct because SSM removes the RP dependency and requires receivers to know the source directly. MP-BGP can carry multicast routing information, but it does not perform RP-to-RP source discovery. BIDIR-PIM is a multicast mode for many-to-many shared-tree forwarding, not an interdomain RP discovery mechanism under RFC 3618. Reference topics: MSDP, RFC 3618, PIM Sparse Mode, interdomain multicast, Source-Active messages, rendezvous points.

The IS-IS hierarchy should place access or internal area routers at Level 1, boundary routers at Level 1/2, and backbone routers at Level 2. In this exhibit, users in areas 25 and 55 must send and receive traffic through both backbone areas, while link flaps in areas 35 and 45 must not affect other areas. Cisco IS-IS design uses Level 1 areas to contain local topology changes and Level 2 routing to interconnect areas through the backbone. Level 1/2 routers sit at the area boundary and leak or advertise reachability between the local Level 1 area and the Level 2 backbone. Option C matches that hierarchy by placing A-series routers as Level 1, B-series routers as Level 1/2, and C-series routers as Level 2. Making too many routers Level 1/2 would expand the impact of topology changes and reduce scaling benefits. Making backbone routers Level 1 would break interarea design. Reference topics: IS-IS hierarchy, Level 1, Level 2, Level 1/2 routers, failure-domain containment, enterprise scaling.

GETVPN is the correct transport-encryption design for this environment. The company is using a private MPLS-based service and requires encryption without maintaining permanent point-to-point tunnels. GETVPN was designed for private WAN environments where routing remains native and packets are encrypted without adding GRE or IPsec tunnel overlays between every pair of sites. It uses group-based keying, typically with key servers that distribute security policy and rekey material to group members. That supports dynamic key rotation and spoke-to-spoke communication while avoiding the operational burden of building and maintaining individual tunnels. DMVPN also supports dynamic spoke-to-spoke tunnels, but it is still a tunnel overlay using mGRE, NHRP, and IPsec, and it is usually selected for Internet or mixed transport overlays. Standard IPsec VPN requires maintaining tunnel relationships, and GRE VPN alone does not provide encryption. GETVPN therefore best matches tunnel-less encryption across a private MPLS WAN with centralized security policy and direct site-to-site forwarding. Reference topics: GETVPN, group encrypted transport, tunnel-less IPsec, private MPLS WAN encryption, group keying.

IP directed broadcast must be enabled on the last Layer 3 device connected to the destination client subnet, which is R2 in the exhibit. Wake-on-LAN uses a magic packet that must reach sleeping hosts on the target LAN. Because sleeping clients often do not have an active IP stack or ARP entry, the WoL packet is commonly sent as a directed broadcast toward the target subnet. Routers forward the packet as a unicast until it reaches the destination subnet, where the last-hop router converts it into a Layer 2 broadcast if directed broadcasts are permitted. Cisco disables directed broadcasts by default on many platforms because of historical amplification-attack risks, so the design should enable it only where needed and protect it with ACLs. Spanning-tree UplinkFast is unrelated to delivering WoL packets; it improves STP convergence on access switches. Enabling directed broadcasts on the wrong router would not place the magic packet onto the client VLAN. Therefore, R2, the last-hop router toward the target WoL clients, is the correct location. Reference topics: Wake-on-LAN, IP directed broadcast, last-hop router behavior, subnet broadcast forwarding, ACL protection.

The correct solution is again a management VRF with SSH keys for device access. This duplicate item tests the same design principle: management traffic should be logically isolated from the overlay and production forwarding paths. A VRF gives the management plane its own routing table, so changes or failures in the overlay do not normally alter management reachability. That makes the network easier to operate because engineers can troubleshoot device access, routing, and overlay behavior as separate concerns. SSH keys satisfy the secure-access requirement by providing encrypted management sessions with public-key authentication. Private VLANs and standard VLANs can segment Layer 2 traffic, but they do not solve routing separation by themselves. TACACS+ and RADIUS provide authentication, authorization, and accounting, but they do not prevent overlay routing from interacting with management reachability. A separate physical interface can help in some designs, but option A is the cleanest answer because it combines routing isolation with secure access. Reference topics: management VRF, SSH, secure management plane, route isolation, overlay troubleshooting.

The correct policy is to prepend the AS path on the nonpreferred advertisement for each prefix. For inbound BGP traffic engineering, the enterprise normally influences remote autonomous systems by changing attributes that those systems see when selecting a path. AS-path prepending makes a route appear less attractive by adding repeated instances of the local AS number to the AS path. In this design, network 10.1.1.0/24 should enter through R3-R1, so R2 must advertise that prefix with a prepended AS path to make the R4-R2 path less preferred unless the primary path fails. Conversely, network 10.1.2.0/24 should enter through R4-R2, so R1 must advertise that prefix with prepending to make the R3-R1 path less preferred. This creates inbound load sharing while preserving failover because the prepended route remains available as a backup. Local preference affects outbound path selection inside the local AS, not inbound selection by the provider. Reference topics: BGP traffic engineering, AS-path prepending, inbound path control, prefix-specific policy, multihomed WAN design.

Lowering the OSPF cost on the direct R1-to-R2 link is the cleanest way to force traffic for 10.10.20.0/24 to prefer that link. OSPF calculates the shortest path using cumulative interface cost, and Cisco designs normally tune OSPF path selection by changing interface cost rather than administrative distance. Administrative distance determines preference between different routing protocols, not between OSPF paths inside the same OSPF process. Moving the link into another area or creating a multiarea adjacency adds design complexity and does not directly solve the requirement unless the resulting cost still becomes lower. The exhibit states that the architect must use the direct link for traffic from 10.10.10.0/24 toward 10.10.20.0/24. Therefore, the direct link must have a lower total OSPF metric than the alternate path. Configuring the link cost to a value below 30 makes OSPF choose it as the preferred intra-area route. This is deterministic, easy to validate with the OSPF database and routing table, and consistent with Cisco hierarchical IGP design practice. Reference topics: OSPF cost, SPF path selection, metric tuning, intra-area routing.

For point-to-point telepresence, asymmetric routing can create delay variation, packet reordering, and troubleshooting complexity. The design requirement is to make egress and ingress flows follow the same path. In the topology, the best way to steer traffic away from the less desirable return path is to configure a higher metric on the router in area 4 so OSPF path selection favors the symmetric path. OSPF chooses paths based on cumulative cost, and increasing the cost on the unwanted path makes the preferred path more attractive without removing redundancy. Route leaking on the routers in area 1 or area 2 would introduce additional interarea route visibility but would not necessarily solve the asymmetric flow problem. A route filter in area 4 could remove reachability or create suboptimal failure behavior rather than simply preferring the right path. Raising the metric is a cleaner design technique because it preserves backup reachability while influencing normal forwarding. Reference topics: OSPF cost design, symmetric routing, telepresence traffic, interarea path optimization, metric engineering.

Dynamic NAT-PT is the correct selection when IPv6 hosts in an IPv6 island must access IPv4-only servers and services. NAT-PT translates between IPv6 and IPv4 packet headers and allows IPv6-only nodes to communicate with IPv4-only destinations by dynamically creating translation state. In this scenario, IPv6 hosts need access to file servers and DNS services in an IPv4 network, so a dynamic translation mechanism is required. Stateless NAT66 and stateful NAT66 are IPv6-to-IPv6 translation mechanisms and do not connect IPv6 hosts to IPv4-only resources. Static NAT-PT would be appropriate for fixed one-to-one mappings where specific hosts are permanently mapped, but the question describes general access from an IPv6 island to IPv4 services, making dynamic NAT-PT the better match. In modern designs, NAT64 and DNS64 are commonly preferred successors, but within the answer choices NAT-PT is the IPv6-to-IPv4 transition mechanism. Reference topics: IPv6 transition, NAT-PT, IPv6-to-IPv4 translation, DNS access, dual-protocol migration.