Ethernet Packet Processing - 3Com 4007 Implementation Manual

150 C 8: E
HAPTER THERNET
Ethernet Packet
Processing
All frames on an Ethernet network are received promiscuously by an
Ethernet port. A port can discard frames for either of the following
reasons:
There is no buffer space available.
The frame is in error.
Figure 1 shows the order in which frame discard tests are made.
Figure 1 How Frame Processing Affects Ethernet Receive Frame Statistics
rxFrames
noRxBuffers
rxInternalErrs
lengthErrs
alignmentErrs
fcsErrs
rxUcastFrames
=
rxMcastFrames
Frames received from the network
Frames discarded because buffer space was exhausted
Frames discarded because frame was in error
Frames delivered by the Ethernet port