CCIE CCIE Network Design 3

Question 1

In a dual-stack IPv4/IPv6 network design, which transition mechanism translates IPv6 packets to IPv4 at the network edge to allow IPv6-only hosts to communicate with IPv4-only destinations?

Accepted Answer

NAT64 with DNS64

Answer

6to4 tunneling

Answer

ISATAP

Answer

Dual-stack lite (DS-Lite)

Question 2

A designer is evaluating whether to use IS-IS or OSPF as the underlay IGP for a large SP MPLS core. Which characteristic gives IS-IS an advantage in very large SP networks?

Accepted Answer

IS-IS is not tied to IP and can continue operating during IP address misconfiguration

Answer

IS-IS uses IP as its transport, making it more resilient

Answer

IS-IS has lower protocol overhead due to smaller LSPs

Answer

IS-IS supports more area types than OSPF

Question 3

Which design consideration is most critical when deploying Cisco SD-WAN (Viptela) to replace a legacy MPLS WAN for a 200-site enterprise?

Accepted Answer

Designing the vSmart controller placement for low-latency OMP route distribution

Answer

Ensuring all sites use the same ISP provider

Answer

Deploying vEdge routers only at hub sites

Answer

Replacing BGP with OSPF at all CE devices

Question 4

A network designer must ensure that a data center can survive the failure of an entire power zone (affecting half the physical servers). Which server connectivity design achieves this?

Accepted Answer

Dual-homed servers with NICs connected to ToR switches in different power zones

Answer

All servers connected to a single ToR switch pair

Answer

Servers connected via a single high-speed uplink to the spine

Answer

Blade chassis with a single fabric module per chassis

Question 5

When designing a campus network for 802.1X port-based authentication, which component acts as the central policy decision point that evaluates authentication requests from network access devices?

Accepted Answer

Cisco ISE (Identity Services Engine)

Answer

RADIUS proxy on the authenticating switch

Answer

TACACS+ server for device administration

Answer

DHCP server with option 82 snooping

Question 6

In a Cisco ACI (Application Centric Infrastructure) design, what is the function of the Endpoint Group (EPG)?

Accepted Answer

A logical grouping of endpoints with shared policy applied through contracts

Answer

A physical grouping of servers by rack location

Answer

A VLAN pool mapped to a physical domain

Answer

A bridge domain with a single subnet

Question 7

A designer is implementing BFD (Bidirectional Forwarding Detection) to accelerate OSPF convergence. Which statement correctly describes BFD's role in this design?

Accepted Answer

BFD provides rapid failure detection independent of OSPF timers and notifies OSPF to reroute

Answer

BFD replaces OSPF hello packets for neighbor discovery

Answer

BFD modifies OSPF SPF calculation intervals automatically

Answer

BFD is only supported on physical Ethernet interfaces, not subinterfaces