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Bring performance and reliability to your network with the Aruba Core, Aggregation, and Access layer switches. Discuss the latest features and functionality of the ArubaOS-Switch and ArubaOS-CX devices, and find ways to improve security across your network to bring together a mobile first solution.
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Speed and duplex in SFP port

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  • 1.  Speed and duplex in SFP port

    Posted Mar 08, 2020 07:33 PM

    Switch: 2930F SFP PoE+ (JL261A)

    Module:1000T-sfp (J8177D)



    Hi, two days ago I was configuring a 2930F SFP uplink interface and had to force it to 100 Mbps and auto duplex. I located a 1 Gbps port for testing, but when I tried to reset the speed/duplex settings for the 2930's SFP interface I received a message that said that such settings couldn't be configured on this port.


    I tried disabling the port to try changin to full auto setting or forced 1000, but it didn't work. I tried with one of the 1-24 interfaces and the command was accepted without problem.


    Finally, out of nowhere I tried again AFTER removing the J8177D module and, finally, I was able to change speed/duplex settings for the interface.


    Is this a normal and expected behaviour for SFP and/or SFP+/28/56 interfaces?


    Thanks in advance.


  • 2.  RE: Speed and duplex in SFP port

    Posted Mar 08, 2020 10:54 PM

    Oh, but I did it:



  • 3.  RE: Speed and duplex in SFP port
    Best Answer

    Posted Mar 09, 2020 02:05 PM



    As noted in the AOS-Switch and AOS-CX Transceiver Guide, page 61:


    J8177C/J8177D support both 100Mbps and 1G operation in this Switch Series.


    However, changing speed settings in an SFP/SFP+ port is not supported while a transceiver is installed and operating. 

  • 4.  RE: Speed and duplex in SFP port

    Posted Mar 09, 2020 02:09 PM

    Thank you, then the right action to do if a speed/duplex change is requiered is to first remove the SFP, make the change, and plug it back.

  • 5.  RE: Speed and duplex in SFP port

    Posted Mar 09, 2020 02:14 PM

    Correct, but note that this only applies to the J8177C/D RJ45 transceivers, as they are the only supported transceiver that is capable of operating at multiple speeds (all supported optical transceivers operate only at a single speed).