Glean Throttling in Cisco NX-OS: Important Facts to Know

Glean Throttling in Cisco NX-OS

Question

Which statement about glean throttling in Cisco NX-OS is true?

Answers

Explanations

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A. B. C. D.

C.

The correct answer for the question is C.

Glean throttling is a feature in Cisco NX-OS that helps to reduce the number of Address Resolution Protocol (ARP) requests sent to the supervisor when forwarding an incoming IP packet in a line card. ARP requests are used to resolve the MAC address for the next hop in a network. When the MAC address is resolved, the line card programs the hardware with the next hop's MAC address and forwards the packet. If the MAC address is not resolved, the line card forwards the packet to the supervisor for resolution.

In order to prevent the forwarding of too many packets to the supervisor for resolution, the glean throttling feature limits the number of ARP requests that are sent from the line card to the supervisor. When the limit is reached, the line card stops sending ARP requests for a period of time, allowing the supervisor to catch up with the requests that it has already received. Once the period of time has elapsed, the line card resumes sending ARP requests.

Option A is incorrect because traffic shaping is a different feature that is used to control the flow of traffic in a network to prevent congestion.

Option B is incorrect because it describes a different feature called rate limiting that is used to manage the access bandwidth policy for a network.

Option D is incorrect because it describes a different feature called traffic policing that is used to limit the maximum rate of traffic through a token bucket algorithm. The token bucket algorithm uses user-configured values to determine the maximum rate of traffic allowed on an interface at a given moment in time.