Users Guide

monitor session-ID: Enables mirror ow control frames on this port.
Changes in the ow-control values may not be reected automatically in show interface output. To display the change, apply the new ow-
control setting, perform a shutdown followed by a no shutdown on the interface, and then check re-display the show interface output for
the port.
Threshold Settings
When the transmission pause is set (tx on), you can set three thresholds to dene the controls more closely. Ethernet pause frames ow
control can be triggered when either the ow control buer threshold or ow control packet pointer threshold is reached.
The following thresholds are provided:
• Number of ow-control packet pointers: from 1 to 2047 (default = 75)
• Flow-control buer threshold in KB: from 1 to 2013 (default = 49KB)
• Flow-control discard threshold in KB: from 1-2013 (default= 75KB)
The pause is started when either the packet pointer or the buer threshold is met (whichever is met rst). When the discard threshold is
met, packets are dropped.
The pause ends when both the packet pointer and the buer threshold fall below 50% of the threshold settings.
The discard threshold denes when the interface starts dropping the packet on the interface. This may be necessary when a connected
device doesn’t honor the ow control frame sent by the switch.
The discard threshold should be larger than the buer threshold so that the buer holds at least hold at least three packets.
Enabling Pause Frames
Enable Ethernet pause frames ow control on all ports on a chassis or a line card. If not, the system may exhibit unpredictable behavior.
NOTE
: Changes in the ow-control values may not be reected automatically in the show interface output. As a
workaround, apply the new settings, execute shut then no shut on the interface, and then check the running–cong of the
port.
NOTE: If you disable rx flow control, Dell Networking recommends rebooting the system.
The ow control sender and receiver must be on the same port-pipe. Flow control is not supported across dierent port-pipes.
To enable pause frames, use the following command.
• Control how the system responds to and generates 802.3x pause frames on 10 Gigabit line cards.
INTERFACE mode
flowcontrol rx [off | on] tx [off | on] [threshold {<1-2047> <1-2013> <1-2013>}] monitor
session-ID
– rx on: enter the keywords rx on to process the received ow control frames on this port.
– rx off: enter the keywords rx off to ignore the received ow control frames on this port.
– tx on: enter the keywords tx on to send control frames from this port to the connected device when a higher rate of trac is
received.
– tx off: enter the keywords tx off so that ow control frames are not sent from this port to the connected device when a
higher rate of trac is received.
– threshold: when you congure tx on, you can set the threshold values for:
◦ Number of ow-control packet pointers: the range is from 1 to 2047 (default = 75).
Interfaces
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