View Full Cisco CCDE 400-007 Exam Dumps and Practice Test Dumps.

 

Question 261

A network architect needs to provide redundant Layer 3 paths between two data center switches while allowing traffic to use all available equal-cost links. Which technology should be considered?

1. STP
2. ECMP
3. HSRP
4. NAT

Correct Answer: 2

Explanation

Equal-Cost Multipath allows a router or Layer 3 switch to install multiple routes toward the same destination when those routes have equivalent routing costs. Traffic can then be distributed across the available paths, improving bandwidth utilization and providing redundancy. If one path fails, traffic can continue through the remaining valid paths. STP is primarily used to prevent Layer 2 loops, HSRP provides first-hop gateway redundancy, and NAT performs address translation. ECMP is therefore the appropriate technology when multiple equal-cost Layer 3 paths should actively participate in forwarding.

Question 262

An enterprise wants to prevent a branch router from becoming a transit point for Internet routes received from one ISP. Which control is most appropriate?

1. Route filtering
2. Increasing MTU
3. Enabling STP
4. Changing the router hostname

Correct Answer: 1

Explanation

Route filtering can prevent unwanted prefixes from being accepted or advertised through a router. In this scenario, inbound and outbound BGP policies can be configured so that only authorized routes are accepted from the ISP and only approved enterprise prefixes are advertised back. This prevents accidental route leaks and unintended transit behavior. MTU configuration affects packet size, STP handles Layer 2 loops, and changing the hostname has no impact on routing advertisements. Proper route filtering is therefore an important control for maintaining predictable BGP routing behavior.

Question 263

A company wants to use a centralized policy to determine which WAN path should carry voice traffic based on latency and jitter measurements. Which solution is most suitable?

1. Traditional STP
2. SD-WAN
3. Static ARP
4. VLAN pruning

Correct Answer: 2

Explanation

SD-WAN can use centralized policies and real-time WAN performance measurements to influence application traffic forwarding. Voice applications are sensitive to latency, jitter, and packet loss, so policies can specify performance requirements and select an available WAN path that satisfies those requirements. If the preferred link no longer meets the configured criteria, traffic can be redirected according to policy. STP is designed for Layer 2 loop prevention, static ARP maps addresses manually, and VLAN pruning controls VLAN propagation. SD-WAN therefore provides the functionality required for application-aware WAN path selection.

Question 264

A service provider has many PE routers and wants to reduce the number of BGP sessions required for exchanging VPN routes. Which architecture can improve scalability?

1. Route Reflectors
2. Full-mesh iBGP only
3. Static routing
4. HSRP

Correct Answer: 1

Explanation

Route Reflectors reduce the need for a full-mesh of iBGP sessions. Instead of every PE router establishing a direct BGP session with every other PE router, selected routers can act as Route Reflectors and distribute routes to their clients. This significantly reduces session count as the network grows. Route Reflectors must be designed carefully because reflection can affect path visibility and routing behavior. A full-mesh becomes increasingly difficult to maintain in large networks, while static routing and HSRP do not solve BGP session scalability. Route Reflectors therefore provide a scalable BGP architecture.

Question 265

A network administrator wants to make one BGP exit path more preferred for outbound traffic across the entire autonomous system. Which attribute should normally be manipulated?

1. MED
2. Local Preference
3. Origin
4. Router ID

Correct Answer: 2

Explanation

Local Preference is commonly used to influence outbound BGP path selection within an autonomous system. A higher Local Preference is normally preferred, allowing administrators to identify which exit point should be used for traffic leaving the AS. Because Local Preference is propagated through iBGP, it can provide consistent outbound path selection across internal routers. MED is primarily used to influence how a neighboring AS selects among multiple entry points, while origin and Router ID are considered later in the BGP decision process. Local Preference is therefore appropriate for this requirement.

Question 266

A company wants to reduce the amount of routing information exchanged between two parts of an OSPF network by advertising an aggregate instead of many individual prefixes. Which feature should be used?

1. Route summarization
2. PBR
3. BFD
4. LACP

Correct Answer: 1

Explanation

OSPF route summarization allows multiple contiguous networks to be represented by a single aggregate prefix at an appropriate routing boundary. This reduces the number of routes advertised between areas or routing domains and can improve scalability. Summarization also helps limit the propagation of individual route changes beyond the summary boundary. PBR changes forwarding behavior, BFD provides fast failure detection, and LACP aggregates physical links. Route summarization is therefore the appropriate feature when the objective is to reduce routing information while maintaining reachability to the summarized networks.

Question 267

A data center uses VXLAN and requires a control-plane mechanism to distribute MAC and IP reachability information between VTEPs. Which technology should be deployed?

1. EVPN
2. DHCP
3. HSRP
4. NAT

Correct Answer: 1

Explanation

EVPN provides a control plane for VXLAN environments by using MP-BGP to distribute MAC and IP reachability information between participating VTEPs. This allows the overlay to learn endpoint information through a scalable control-plane mechanism rather than relying solely on data-plane flooding. EVPN also supports advanced capabilities such as integrated Layer 2 and Layer 3 services and multi-homing designs. DHCP provides host configuration, HSRP provides gateway redundancy, and NAT performs address translation. EVPN is therefore the appropriate control-plane technology for a VXLAN-based data center fabric.

Question 268

An organization needs to prevent users in one department from directly reaching another department’s network while still allowing both departments to access shared services. Which design approach is appropriate?

1. VRF-based segmentation
2. Single flat VLAN
3. Unrestricted Layer 2 bridging
4. Shared default gateway without policy

Correct Answer: 1

Explanation

VRF-based segmentation can provide separate routing tables for different departments or security zones. Shared services can then be exposed through controlled route leaking, firewall policies, or other explicit security mechanisms. This provides logical separation while still allowing approved communication. A flat VLAN or unrestricted Layer 2 bridging would make direct communication easier and reduce segmentation. Simply using a shared default gateway without policy does not provide sufficient isolation. VRF-based segmentation is therefore an effective architectural approach when independent routing domains and controlled service access are required.

Question 269

A network engineer needs to identify whether a BGP route has passed through several autonomous systems. Which BGP attribute provides this information?

1. Local Preference
2. AS Path
3. MED
4. Weight

Correct Answer: 2

Explanation

The BGP AS Path attribute records the sequence of autonomous system numbers that a route advertisement has traversed. It provides important information about the route’s path through different autonomous systems and is also used in BGP loop prevention. In general, BGP prefers a shorter AS path when other relevant selection criteria are equal. Local Preference primarily influences outbound path selection within an AS, while MED can influence inbound path selection between neighboring ASes. Therefore, the AS Path attribute provides the required information about autonomous-system traversal.

Question 270

A network architect wants to provide a default gateway that remains available when one physical router fails. Which technology is designed for this requirement?

1. HSRP
2. BGP
3. VXLAN
4. LACP

Correct Answer: 1

Explanation

HSRP provides first-hop gateway redundancy by allowing multiple routers to participate in a virtual gateway group. End devices use a virtual IP address as their default gateway instead of depending directly on one physical router. If the active router becomes unavailable, another participating router can assume the active role and continue forwarding traffic. BGP handles routing between autonomous systems, VXLAN provides network virtualization, and LACP combines physical links. HSRP therefore directly addresses the requirement for a highly available default gateway.

Question 271

A company wants to control which prefixes a BGP neighbor is allowed to advertise into the enterprise network. Which mechanism should be applied to inbound routes?

1. Prefix list or route policy
2. STP priority
3. LACP timer
4. DHCP snooping

Correct Answer: 1

Explanation

Inbound prefix filtering or routing policy can control which routes are accepted from a BGP neighbor. The administrator can define permitted prefixes and reject all unexpected or unauthorized advertisements. This is important for preventing route leaks, accidental advertisements, and unnecessary routing-table growth. A prefix list can be combined with route maps or policy frameworks to provide more advanced matching and actions. STP priority controls spanning-tree elections, LACP manages link aggregation, and DHCP snooping provides Layer 2 security. Therefore, inbound prefix filtering is the appropriate mechanism.

Question 272

An enterprise wants to connect two routing domains that use different routing protocols while maintaining controlled exchange of selected routes. Which technique is required?

1. Route redistribution with filtering
2. MAC address learning
3. STP root election
4. LACP

Correct Answer: 1

Explanation

Route redistribution allows routes learned through one routing protocol to be introduced into another protocol. When multiple routing domains use different protocols, redistribution can provide connectivity between them. However, unrestricted redistribution can introduce routing loops, duplicate routes, and suboptimal paths. Filtering and route policies should therefore be used to control which prefixes are redistributed and in which direction. MAC learning, STP, and LACP operate at different layers and do not exchange routing information between protocols. Controlled route redistribution is therefore appropriate for this requirement.

Question 273

A service provider wants to ensure that two customers using the same private IPv4 prefix remain completely separate within an MPLS VPN environment. Which combination provides route uniqueness and VPN membership control?

1. RD and RT
2. HSRP and LACP
3. ECMP and BFD
4. STP and VLAN pruning

Correct Answer: 1

Explanation

Route Distinguishers and Route Targets perform complementary functions in MPLS Layer 3 VPNs. The Route Distinguisher makes overlapping customer prefixes unique when they are carried as VPNv4 or VPNv6 routes. Route Targets determine which VPN routes are imported into or exported from particular VRFs. Together, they allow different customers to use overlapping address spaces while maintaining logical separation and controlled route distribution. HSRP and LACP provide redundancy and link aggregation, while ECMP and BFD address forwarding and failure detection. RD and RT are therefore the appropriate combination.

Question 274

A network uses multiple equal-cost paths and wants packets from the same application flow to remain on the same path to reduce the possibility of packet reordering. Which method is commonly used?

1. Per-flow hashing
2. Per-packet random forwarding
3. Broadcast replication
4. Route suppression

Correct Answer: 1

Explanation

Per-flow hashing uses selected packet-header fields, such as source and destination addresses and transport ports, to calculate a consistent forwarding path for a flow. This allows multiple flows to be distributed across equal-cost paths while keeping packets belonging to the same flow on the same path. This reduces the likelihood of packet reordering compared with per-packet load balancing. Per-packet random forwarding may send consecutive packets over different paths, while broadcast replication and route suppression serve different purposes. Per-flow hashing is therefore commonly used with ECMP environments.

Question 275

A company wants to provide Internet connectivity to branch offices through local breakout while keeping sensitive corporate traffic on an encrypted overlay. Which architecture can support this requirement?

1. SD-WAN with policy-based traffic steering
2. STP-only WAN
3. Static ARP across all branches
4. Single Layer 2 broadcast domain

Correct Answer: 1

Explanation

SD-WAN can apply different policies to different classes of traffic. Internet-bound traffic can use local Internet breakout, while sensitive corporate traffic can be directed through encrypted tunnels toward headquarters, cloud security services, or other authorized destinations. The controller and edge devices can enforce application-aware policies based on destination, application, security requirements, and WAN conditions. STP does not provide this type of WAN traffic steering, and static ARP or a single Layer 2 domain does not provide secure application-aware path control. SD-WAN with policy-based steering therefore fits the requirement.

Question 276

A network architect wants to prevent unnecessary Layer 2 broadcast traffic from crossing a routed boundary between network segments. Which design principle should be used?

1. Layer 3 segmentation
2. Single VLAN extension
3. Transparent bridging everywhere
4. Large Layer 2 domain

Correct Answer: 1

Explanation

Layer 3 segmentation creates routed boundaries between network segments, preventing Layer 2 broadcast domains from extending unnecessarily across the entire infrastructure. Broadcast traffic remains within its local Layer 2 domain, while routers or Layer 3 switches forward unicast traffic between networks. This improves scalability and failure isolation and reduces the impact of Layer 2 problems. A single VLAN extension or large Layer 2 domain expands the broadcast scope, while transparent bridging preserves Layer 2 adjacency. Layer 3 segmentation is therefore the appropriate design principle.

Question 277

A BGP administrator wants to identify routes that should receive special treatment across multiple routers without creating separate policies for every prefix. Which feature is most suitable?

1. BGP communities
2. STP bridge priority
3. OSPF hello interval
4. Ethernet MTU

Correct Answer: 1

Explanation

BGP communities provide a scalable method for tagging routes with policy information. Instead of matching every prefix individually, administrators can assign a community to a group of routes and apply policies based on that tag. Communities can be used for route advertisement control, traffic engineering, customer classification, and other routing policies. STP bridge priority controls root bridge selection, OSPF hello intervals affect neighbor detection, and MTU determines maximum frame size. BGP communities therefore provide an efficient mechanism for applying consistent policies to groups of BGP routes.

Question 278

A network has a critical WAN link where rapid failure detection is required, but the routing protocol’s normal timers are too slow. What should the architect implement?

1. BFD
2. DNS
3. NAT
4. DHCP

Correct Answer: 1

Explanation

BFD is designed for rapid detection of forwarding-path failures. It can operate alongside routing protocols and provide fast notifications when the monitored path becomes unavailable. This allows routing protocols to react without waiting for their standard hello or hold timers to expire. BFD is particularly useful in WAN, service-provider, and data center environments where rapid convergence is important. DNS handles name resolution, NAT performs address translation, and DHCP provides IP configuration. Therefore, BFD is the most appropriate technology for accelerating detection of a WAN path failure.

Question 279

A company has several Internet connections and wants to control outbound traffic so that internal routers consistently prefer one provider over another. Which BGP attribute should be used?

1. MED
2. Local Preference
3. AS Path length only
4. Router ID

Correct Answer: 2

Explanation

Local Preference is used within an autonomous system to influence outbound BGP path selection. By assigning a higher Local Preference to routes learned through the preferred provider, internal routers can consistently select that provider as the primary exit path. A lower Local Preference can be assigned to the backup provider. MED is generally used to influence how a neighboring AS chooses among multiple entry points, while AS-path manipulation is more commonly used to influence inbound traffic. Router ID is mainly used as a later tie-breaker. Local Preference is therefore appropriate for outbound traffic engineering.

Question 280

A large enterprise wants to reduce the number of routes advertised across a WAN while ensuring that remote sites can still reach the summarized address space. Which technique should be implemented?

1. Route summarization
2. MAC flooding
3. Broadcast forwarding
4. Packet fragmentation

Correct Answer: 1

Explanation

Route summarization aggregates multiple more-specific prefixes into a single larger prefix. Advertising the summary instead of every individual route reduces routing-table size and the amount of routing information exchanged across the WAN. It can also reduce the impact of individual route changes because remote routers may only see the aggregate. The summary must be carefully designed to avoid attracting traffic for destinations that are not actually reachable. MAC flooding, broadcast forwarding, and packet fragmentation do not reduce routing information. Route summarization is therefore the appropriate solution for improving WAN routing scalability.