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Why do I see the Jumbo counter increment for frames with a payload size of 1500 bytes on VDX?

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TitleWhy do I see the Jumbo counter increment for frames with a payload size of 1500 bytes on VDX?
Question
VDX
NOS
Environment
Answer
The interface counters include the entire size of the frame into the statistics counters for the interface, including the Frame Check Sequence.
The maximum header size for an IEEE 802.3 Ethernet frame is 14 bytes. (Destination MAC, Source MAC, Ethertype)

1) Untagged Ethernet Frame: 14 byte header + 1500 byte payload + 4 byte FCS = 1518 bytes
2) 802.1Q Tagged Ethernet Frame: 14 byte header + 4 byte 802.1Q tag + 1500 byte payload + 4 byte FCS = 1522 bytes
3) Q-in-Q Tagged Ethernet Frame: 14 byte header + 4 byte 802.1Q tag + 4 byte 802.1ad + 1500 byte payload + 4 byre FCS = 1526 bytes

In case 2) & 3) the "Over 1518-byte pkts(Jumbo)" counter will increment for a frame with payload 1500 bytes.
In case 1) the "Over 1023-byte pkts" will increment with a frame of 1500 bytes.

More details on Ethernet Frames can be found here: http://en.wikipedia.org/wiki/Ethernet_frame
More detail on FCS (Frame Check Sequence) can be found here: http://en.wikipedia.org/wiki/Frame_check_sequence

A lab test can be performed to verify this behavior.
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