The traffic is transmitted through Eth-Trunk interfaces which consist of two 10G interfaces.
When the Eth-Trunk is in access mode everything works without any problems but when Eth-Trunk is switched to trunk mode the frame errors starts to appear.
802.3 Ethernet frame structure
The minFrameSize of 802.3 Ethernet frame is 64 bytes. So this is the minimal size of the Ethernet frame which can be send through a network.
When we have “payload” smaller than 46 bytes in such case we have to use padding to fill the rest free space to 46 bytes.
For example when we wish to send 40 bytes of payload then 6 bytes will be added as padding to the payload in order to receive 46 bytes of Ethernet payload. Then such payload is encapsulated by Ethernet frame header and tailor. Total size is increasing by 18 bytes when not using VLAN tagging or by 22 bytes when VLAN tagging is used.
In a case when the device receives a untagged frame whith total size 64 bytes (minFrameSize) it means that the padding size must be >= 0, and the “length field” should be <= the “computed length” of the data field which is the “payload” size.
If the “length field” is greater than the “computed DATA length” that means the length field has error and frame error counter increase
When the device receives a tagged or untagged frame, which total size of the frame is greater than minFrameSize (greater than 64 bytes) in such case device assumes that the padding size must be zero (no padding is used).
Additionally the “length field” should be equal to the “computed DATA length” (payload size). Otherwise the length field is not correct and the frame error counter increase.