Enabling or disabling flow control (CLI)

NOTE:

You must enable flow control on both ports in a given link. Otherwise, flow control does not operate on the link and appears as Off in the show interfaces brief port listing, even if flow control is configured as enabled on the port in the switch. (See The show interfaces brief command listing example.) Also, the port (speed-duplex) mode must be set to Auto (the default).

To disable flow control on some ports, while leaving it enabled on other ports, just disable it on the individual ports you want to exclude.

(You can find more information on flow control in the Table 3: Status and parameters for each port type table.)

Syntax: 


no interface <port-list> flow-control

Enables or disables flow control packets on the port. The no form of the command disables flow control on the individual ports. (Default: Disabled.)

Examples:

Suppose that:

  1. You want to enable flow control on ports A1-A6.

  2. Later, you decide to disable flow control on ports A5 and A6.

  3. As a final step, you want to disable flow control on all ports.

Assuming that flow control is currently disabled on the switch, you would use these commands:

Figure 8: Configuring flow control for a series of ports
switch(config)# int a1-a6 flow-control

switch(config)# show interfaces brief

 Status and Counters - Port Status

                   | Intrusion                           MDI  Flow Bcast
  Port   Type      | Alert     Enabled Status Mode       Mode Ctrl Limit
  ------ --------- + --------- ------- ------ ---------- ---- ---- ----- 
  A1     10GbE-T   | No        Yes     Up     1000FDx    NA   on   0
  A2     10GbE-T   | No        Yes     Up     10GigFD    NA   on   0
  A3     10GbE-T   | No        Yes     Up     10GigFD    NA   on   0
  A4     10GbE-T   | No        Yes     Up     10GigFD    NA   on   0
  A5     10GbE-T   | No        Yes     Up     10GigFD    NA   on   0
  A6     10GbE-T   | No        Yes     Up     10GigFD    NA   on   0
  A7     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A8     10GbE-T   | No        Yes     Up     10GigFD    NA   off  0

switch(config)# no int a5-a6 flow-control

switch(config)# show interfaces brief

 Status and Counters - Port Status

                   | Intrusion                           MDI  Flow Bcast
  Port   Type      | Alert     Enabled Status Mode       Mode Ctrl Limit
  ------ --------- + --------- ------- ------ ---------- ---- ---- ----- 
  A1     10GbE-T   | No        Yes     Up     1000FDx    NA   on   0
  A2     10GbE-T   | No        Yes     Down   10GigFD    NA   on   0
  A3     10GbE-T   | No        Yes     Down   10GigFD    NA   on   0
  A4     10GbE-T   | No        Yes     Down   10GigFD    NA   on   0
  A5     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A6     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A7     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A8     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0

switch(config)# no int a1-a4 flow-control

switch(config)# show interfaces brief

 Status and Counters - Port Status

                   | Intrusion                           MDI  Flow Bcast
  Port   Type      | Alert     Enabled Status Mode       Mode Ctrl Limit
  ------ --------- + --------- ------- ------ ---------- ---- ---- ----- 
  A1     10GbE-T   | No        Yes     Down   1000FDx    NA   off  0
  A2     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A3     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A4     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A5     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A6     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A7     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0
  A8     10GbE-T   | No        Yes     Down   10GigFD    NA   off  0