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Flow-control on 3650

Dear all,

 

I tried to enable flow-control on my interface but from a "show interface" it show me that is not supported.

Here my configuration :

 

interface GigabitEthernet1/0/48
 switchport access vlan 51
 switchport mode access
 flowcontrol receive on
 spanning-tree portfast

 

and the output of a "show interface gi1/0/48"

  MTU 9198 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 7/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00

 

I can't find issue related to this IOS version. Has anybone meet this type of problem ?

 

Thanks

13 Replies 13

Reza Sharifi
Hall of Fame
Hall of Fame

Hi

That is a normal/default behavior for 3650, 3850 and other small switches.

input flow-control is off, output flow-control is unsupported 

HTH 

Hi Reza,

 

So flow control is enabled correctly but is normal that is see "output flow-control is unsupported " ?

 

Thanks

Hi,

Yes, that is correct. output flow-control is unsupported on these switches.

I know it is supported on the Nexus series.

HTH

Joseph W. Doherty
Hall of Fame
Hall of Fame
BTW, do you really understand what's all to be considered when using Ethernet flow control? Unless you're a real master, it's often best not used.

Hello Joseph,

 

Yes I know what is mean, but I don't inderstand why I have the possibility to configure the port with flow-control and in reality is not enabled ?

 

Thanks

Laugh - well that's a question that could only be answered by Cisco.

I have only seen flow control changes in server and storage environments, and I think that is the reason you can change that on the Nexus series switches.

HTH

Dell has impose us to activate flow-control and I'm little bit frustrated about this problem.

Do you know if is an IOS problem ?

 

Thanks for your help

No, this is not an IOS issue.  The platform does not support it. I have seen dell suggesting that for Nexus platform before but flow control change usually does not help.  You may want to open a ticket with Cisco to see if they support it in any IOS version and try it.

HTH

Just for your information, according Cisco page "Cisco feature Navigator"flowcontrol is supported on version 16.6.1 but in reality is not supported because after upgrade our switches flowcontrol it seem's not activated.

 

Thank you Cisco

ralshbou
Cisco Employee
Cisco Employee

please check the below bug:

 

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCve92821/?reffering_site=dumpcr

 

basically the feature was broken so they submitted this bug.

Hi .

 

3650 version 03.07.05E has the same Bug....

 

show int gigabitEthernet 2/0/45 flowcontrol
Port       Send FlowControl  Receive FlowControl  RxPause TxPause
           admin    oper     admin    oper
---------  -------- -------- -------- --------    ------- -------
Gi2/0/45   Unsupp.  Unsupp.  on       off         0       0

yes! basically it is not software dependent, it depends on the platform so what it says overall that 3650/3850 have this limitation despite which software they are running :)

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