Cisco ASA Series Cli Configuration Manual page 429

Chapter 1 Starting Interface Configuration (ASA 5510 and Higher)
Command
Step 5
(Optional)
flowcontrol send on [low_water high_water
pause_time] [noconfirm]
Example:
hostname(config-if)# flowcontrol send on
95 200 10000
Step 6
no shutdown
Example:
hostname(config-if)# no shutdown
What to Do Next
Optional Tasks:
•
•
•
Required Tasks:
•
Configure redundant interface pairs. See the
page 1-26.
Configure an EtherChannel. See the
Configure VLAN subinterfaces. See the
section on page 1-31.
For multiple context mode, assign interfaces to contexts and automatically assign unique MAC
addresses to context interfaces. See the
Starting Interface Configuration (ASA 5510 and Higher)
Purpose
Enables pause (XOFF) frames for flow control on 1-Gigabit and
10-Gigabit Ethernet interfaces.
If you have a traffic burst, dropped packets can occur if the burst
exceeds the buffering capacity of the FIFO buffer on the NIC and
the receive ring buffers. Enabling pause frames for flow control
can alleviate this issue. Pause (XOFF) and XON frames are
generated automatically by the NIC hardware based on the FIFO
buffer usage. A pause frame is sent when the buffer usage exceeds
the high-water mark. The default high_water value is 128 KB (10
GigabitEthernet) and 24 KB (1 GigabitEthernet); you can set it
between 0 and 511 (10 GigabitEthernet) or 0 and 47 KB
(1 GigabitEthernet). After a pause is sent, an XON frame can be
sent when the buffer usage is reduced below the low-water mark.
By default, the low_water value is 64 KB (10 GigabitEthernet)
and 16 KB (1 GigabitEthernet); you can set it between 0 and 511
(10 GigabitEthernet) or 0 and 47 KB (1 GigabitEthernet). The link
partner can resume traffic after receiving an XON, or after the
XOFF expires, as controlled by the timer value in the pause frame.
The default pause_time value is 26624; you can set it between 0
and 65535. If the buffer usage is consistently above the high-water
mark, pause frames are sent repeatedly, controlled by the pause
refresh threshold value.
When you use this command, you see the following warning:
Changing flow-control parameters will reset the
interface. Packets may be lost during the reset.
Proceed with flow-control changes?
To change the parameters without being prompted, use the
noconfirm keyword.
Note
Only flow control frames defined in 802.3x are supported.
Priority-based flow control is not supported.
Enables the interface. To disable the interface, enter the
shutdown command. If you enter the shutdown command, you
also shut down all subinterfaces. If you shut down an interface in
the system execution space, then that interface is shut down in all
contexts that share it.
"Configuring a Redundant Interface" section on
"Configuring an EtherChannel" section on page
"Configuring VLAN Subinterfaces and 802.1Q Trunking"
"Configuring Multiple Contexts" section on page
Cisco ASA Series CLI Configuration Guide
1-28.
1-15.
1-25