Administrator Guide

Switch Management Commands 2219
port that is experiencing congestion (incast); if the cell count continues to
increase over time, the port begins discarding packets when reaching the tail
drop threshold.
The value of 10 cells above corresponds to one and one-half maximum length
packets queued for transmission. For the N2000/N3000 and N4000 switches,
the cell size is 208 bytes; for the N1500, the cell size is 128 bytes. If jumbo
frames are enabled (MTU 9200), the expected size of a single maximum
length packet is 45 cells (9200/208 = 44.2). Allowing for a frame and a half to
be buffered on average, a value of 75 is perhaps more appropriate to consider
as the indicator for determining if congestion exists on a port.
The clear counters command clears the underlying counters for transmit and
receive utilization values, transmit and receive packets per second values, and
the drops counter. The count of buffered packets is not a sampled counter
and cannot be cleared.
This command displays the following interface transmit and receive
utilization in bits/sec and packets/sec.
Field Description
Port The interface for which information is
displayed.
Load Interval The load interval for the interface.
Oper. Speed The operational speed, which is the
speed at which the interface is currently
operating (e.g., 1M, 10M, 100M, 1G,
10G, 40G).
Rx Util The receive utilization which is the link
utilization in the receive direction as a
percentage of operational speed (range
0-100). The utilization is derived by
dividing the link speed by the number of
bytes received averaged over the last
sampling interval.
2CSNXXX_SWUM204.book Page 2219 Monday, January 25, 2016 1:25 PM