Setup Guide
monitor session-ID: Enables mirror ow control frames on this port.
Changes in the ow-control values may not be reected 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 dene the controls more closely. Ethernet pause frames ow
control can be triggered when either the ow control buer 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 buer 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 buer 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 buer threshold fall below 50% of the threshold settings.
The discard threshold denes 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 buer threshold so that the buer 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 reected 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–cong 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 dierent 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 trac 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 trac is received.
– threshold: when you congure tx on, you can set the threshold values for:
◦ Number of ow-control packet pointers: the range is from 1 to 2047 (default = 75).
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Interfaces