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  • 1.  ESX Host Trunk port on Cisco Fabric Extender

    Posted Jan 30, 2012 07:20 PM

    I'm also going to pose this question with Cisco but am curious if anyone has tried to configure a Fabric Extender host port as a Trunk in order to connect an ESX 4.1 host to it.  I understand that you cannot attach another switch that is reliant upon STP to a Fabric Extender host port because that host port will go into error disable mode as soon as it sees a BPDU.  I do not believe that a virtual switch relies on STP and therefore could potentially fall into the below FEX configuration caveat.

    When I hook an ESX host up to my FEX host port configured as a trunk, the port does not go into err-disable mode but I cannot connect to any of the trunked VLANs either.  The FEX host port shows up/up.

    Per the Fabric Extender config documentation from Cisco:

    Any edge switch that leverages a link redundancy mechanism not dependent on Spanning Tree such as
    Cisco Flexlink or vPC (with BPDUFilter enabled) may be connected to a Fabric Extender host interface.
    Since spanning tree is not utilized to eliminate loops, care must be taken to ensure a loop-free topology
    below the Fabric Extender host interfaces.

    Has anyone else tried this configuration?



  • 2.  RE: ESX Host Trunk port on Cisco Fabric Extender

    Posted Jan 30, 2012 08:17 PM

    I have not tried that configuration, but just want to confirm that the virtual switches does not support STP. That is, they will not send any STP BPDUs and will silently drop any incoming BPDU frames.

    As for VLANs the vSwitches are fully 802.1Q compatible, so there might be some configuration issue that makes it not working at the momemt.



  • 3.  RE: ESX Host Trunk port on Cisco Fabric Extender

    Posted Jan 30, 2012 09:20 PM

    Agreed....they do not participate in Spanning Tree and are able to connect to dot1q ports.  Which is why I believe this configuration should work.



  • 4.  RE: ESX Host Trunk port on Cisco Fabric Extender

    Posted Jan 30, 2012 09:25 PM

    How are the VLANs setup inside the ESX host?