Free Practice Questions for Cisco 400-007 Exam

A: Flow-based analysis allows understanding bandwidth usage across apps and sessions, crucial for voice/video capacity management.

C: Call management systems track CAC and call quality failures, key for voice/video troubleshooting.

D: Active synthetic probes proactively inject traffic to monitor loss, latency, and jitter under real-time conditions.

Why other options are incorrect:

B: Network convergence is not directly analyzed through call management tools.

E: Passive synthetic probes is not an accurate term; passive monitoring refers to analysis of real traffic flows, not synthetic tests.

F: PTP time-stamping is more applicable to clock synchronization, not regular voice/video performance monitoring.

Comprehensive and Detailed Explanation:

A: QoS (Quality of Service) helps preserve performance for critical applications when only one link is available by prioritizing high-value traffic. This solution works within existing infrastructure—meeting the "no additional CAPEX" requirement.

Other options:

B and C introduce new hardware or services—thus increase CAPEX.

D: Dynamic routing helps with failover but doesn't solve the bandwidth issue under failure conditions; QoS does.

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IPFIX probes can perform deep flow inspection beyond what routers/switches natively collect, making them well suited for security monitoring (DDoS detection, anomaly detection, intrusion attempts).

Probes can extract Layer 7 information unavailable from normal router flow records.

Why other options are incorrect:

A, C, D: Can also be done using router-integrated flow exports; dedicated probes are primarily deployed for advanced security visibility.

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In IPv6, routers advertise prefixes via Router Advertisement (RA) messages. An attacker could inject rogue RAs to manipulate the IPv6 configuration of endpoints.

Router Advertisement Guard (RA Guard) blocks unauthorized RA messages from being received on access ports, preventing endpoints from receiving incorrect IPv6 prefixes from malicious or misconfigured devices.

This security feature is crucial when devices have IPv6 enabled but the network is IPv4-only.

Other options explained:

A: Source Guard and Prefix Guard enforce valid address and prefix assignment but do not prevent RA spoofing directly.

C: Prefix Guard focuses on controlling prefixes being assigned, not blocking RA messages.

D: Secure Neighbor Discovery (SEND) provides cryptographic protection but is rarely deployed due to complexity.

To split an Ethernet domain and ensure isolation of configuration and topology changes, the key mechanism is separating the VLAN management domains. This is achieved through:

VTP (VLAN Trunking Protocol) domain separation

Each VTP domain controls its own set of VLAN information and will not propagate VLAN changes across domain boundaries. By assigning unique VTP domain names to each half of the network, administrators prevent unintended synchronization of VLANs between switches.

Other options:

B. VTP password: Adds security but does not separate domains.

C. STP type: All switches in the domain can run the same or different STP versions and still be part of the same Ethernet domain.

D. VLAN ID: These can overlap across domains; uniqueness is not required to split domains.

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When a service provider does not support multicast over their Layer 3 VPN, the enterprise can useGRE tunnels between Customer Edge (CE) devicesto transport multicast traffic. This method allows the customer to encapsulate multicast packets in unicast GRE packets, which are routable through the provider’s non-multicast core.

In this scenario, the most scalable and immediate solution is to establish a GRE tunnel betweenC2 (in the head office CE router path)andC4 (at the branch office). This setup ensures that multicast traffic originating at the head office is tunneled directly to the multicast receivers, bypassing the service provider’s non-multicast-aware core.

This strategy is directly aligned with CCDE v3.1 principles, which emphasize:

Minimizing service provider dependency

Providing a scalable, customer-controlled overlay solution

Ensuring protocol compatibility across domains

Why other options are incorrect:

A: Tunnel between CE1 and CE2 is less optimal, as it may not originate or terminate at the exact multicast endpoints.

C: Tunnel between C1 and C4 is less aligned with CE-to-CE design expectations and may bypass required edge security/policy controls.

D: 2547oDMVPN is more complex and intended for full-scale VPN overlays, not quick multicast solutions.

E: Draft Rosen requires service provider support, which is currently unavailable, hence not a valid short-term option.

This solution ensures operational simplicity and future scalability with minimal provider dependency, which are core principles outlined in the CCDE v3.1 design methodology.

GLOP addressing is defined in RFC 2770. It assigns globally unique multicast addresses based on an organization's ASN by mapping the 16-bit ASN into the middle two octets of the 233.0.0.0/8 address space.

233.0.0.0/8 is specifically reserved for GLOP addressing.

The uniqueness of the address is derived from the assigned ASN.

Why other options are incorrect:

A: 232.0.0.0/8 is SSM address space.

C: 239.0.0.0/8 is for administratively scoped multicast.

D: 224.0.0.0/24 is reserved for local multicast (link-local scope).

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D (Data confidentiality rules): The most critical factor in cloud service placement is data confidentiality and compliance with regulatory requirements. Certain data may not legally or contractually be permitted to leave specific geographic or organizational boundaries, directly influencing whether a public, private, hybrid, or on-premise deployment is used.

Other options explained:

A: Replication cost is important but secondary to legal and regulatory compliance.

B: Application structure affects architecture but doesn't override confidentiality restrictions.

C: Implementation time is a project management concern, not a service placement driver.

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B (BFD Echo):BFD Echo mode uses local hardware-based loopback mechanisms for even faster fault detection than regular BFD asynchronous mode, significantly reducing failure detection time and thus convergence delay.

Other options explained:

A/D: OSPF fast hellos improve OSPF detection but are still control-plane driven and slower than hardware-based BFD Echo.

C: BGP is slower to converge than OSPF, especially for IGP-like designs.

Comprehensive and Detailed Explanation:

D: The most effective solution is to have Site-X advertise a more specific (longer) prefix (e.g., 100.75.10.0/24), which allows external BGP routers to prefer Site-X over Site-Y. This ensures traffic destined for Site-X flows directly to it, preserving symmetry. Additionally, control plane coordination between R1 and R2 ensures proper routing consistency and minimizes the risk of loops or misdirection.

Other options:

A: Using BGP MED works within the same AS; it is often ignored by external ISPs.

B: Replicating firewall behavior does not address the routing issue.

C: DNS manipulation is a workaround—not a scalable or robust design solution.

This solution is consistent with BGP best practices and CCDE v3.1 guidance on traffic engineering and policy-based routing.