How to turn on sending flow control packet of C3560CX?

[mirage1012]

I've bought 4 C3560CX switch and found this switch can not send flow control packet(pause frame).

Anyone can help me to turn on this feature?

It is necessary for me to have this feature.

Many thanks. 

[Mark Malone]

does it show on the interface as on or off or even there ?

GigabitEthernet0/0/0 is up, line protocol is up
  Hardware is ISR4331-3x1GE,
  Description: 
  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  Full Duplex, 1000Mbps, link type is auto, media type is RJ45
  output flow-control is on, input flow-control is on

[mirage1012]

Hi Mark

    Many thanks for your kindly reply.

The console show "input flow-control is on output flow-control is unsupported"

I've tried to turn on the output flow control by following commands.

"flowcontrol transmit on" and "flowcontrol send on"

The console shows "Invalid input detected".

[Mark Malone]

Hi

its unsupported so you cant turn on flowcontrol outbound , if it was supported you would just see flowcontrol off

as per doc its flow control on 3560 is receive only

http://leighfinch.net/cisco_wiki/index.php/Flow_control

[mirage1012]

Hi Mark

    Is there any other way to turn on the flow control on transmit side?

I believe the hardware supports tranmiting flow control packets and only blocked by firmware.

The flow control on transmit side is necessary for me, it's very depressed that I've just cost $6000 to get 4 switchs without flow control on transmit side.

Many thanks  

[Mark Malone]

not sure about a way to get around the flow control output looks like its always been turned off  on output on all 3560s not just compacts  looking through the papers

why not see what's causing the issue and then use qos to mitigate it , flowcontrol is basically a quick way of doing it but it effects all traffic and that's why it may be disabled on output as well it has issues with certain vendor traffic   , qos you could narrow it down to the ip address of the suspect devices or traffic that may be overloading the interface and causing pause frames , I don't think though you an use span for pause frames

as per this doc too , you cant enable it

By default flowcontrol is disabled and you can only enable a Cisco switch to receive PAUSE frames, but not to send them.

http://blog.ine.com/2008/07/08/802-3x-flow-control/

Your server is overloading the interface in hardware so the switch may be under specked for whats required as it cant handle the amount of data and wants it to slow down  , how much traffic is being pumped through the interface that your seeing the pause frames on  , I would slow it down from the server side see if that helps the switch end

[Joseph W. Doherty]

As Mark notes, as pause frames block all traffic, QoS prioritization is often considered the "better" solution unless you're working with an enhanced Ethernet protocol, such as DCB as mentioned in Mark's reference link.

If you describe why you believe you need pause frame support, perhaps someone might suggest an alternative.