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What is the answer for this CCIE question ??

What is the answer for this question ??

A service provider allowed private IPv6 BGP peering with a university research network. On receiving IPv6 traffic, one Cisco 12000 Series Router that is located in the path of IPv6 traffic experienced high CPU use on its single-port OC192 line card that caused OSPF adjacency to drop on its port. Prior to receiving IPv6 traffic, this OC192 port was passing approximately 1 Gb of IPv4 traffic without any noticeable CPU use. What are two possible reasons for this performance problem? (Choose two.)

A. IPv6 neighbor discovery is enabled. It should be disabled on point-to-point links because this helps with CPU use.

B. IPv6 DAD is enabled. It should be disabled in the service provider core.

C. The line card is not capable of hardware forwarding of IPv6 traffic.

D. The line card has an old fabric loader and FPGA code.

E. Cisco Express Forwarding has been disabled on the line card.

F. Some of the IPv6 traffic contains extension headers causing increased CPU use.

Cisco Employee

What is the answer for this CCIE question ??

Hello Haris,

A rise in CPU usage related to a new traffic passing through a device suggests that the traffic must be process switched. In this case, it would indicate issues with hardware forwarding of the IPv6 traffic. Hence, I would personally go with C and F.

Best regards,


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