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  • 1.  Spanning Tree Path Cost

    Posted 09-25-2022 03:15 PM
    Recently added a secondary path on our fibre switch (Aruba JL075A 3810M-16SFP+-2-slot Switch). Our primary link is a trunk port and I was expecting STP to automatically use port Trk1 as the forwarding port however it choose the secondary link as the forwarding port blocking Trk1 port. Notice that the path cost on spanning tree shows that both port are on 1 Gbps link speed equals a path cost of 20,000.

    14 1000SX | 20000 128 Forwarding | 68bdab-5dd180 2 Yes No
    Trk1 | 20000 64 Blocking | 68bdab-5dd180 2 Yes No

    Why didn't the spanning tree automatically choose 2 Gbps link speed equals a path cost of 10,000 on Trk1 ? I know I can configure the path cost and it should use Trk1 as the forwarding port.

    Could it be that my other end is using a two stacked Cisco switch and I distribute the fibre connection to both switch fibre ports in the stack ?



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    Usaia Tawakevou
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  • 2.  RE: Spanning Tree Path Cost

    Posted 09-27-2022 09:38 PM

    Hi Usaia,

    This is an enterprise switch. Our friends in the Airhead Community will be able to better assist you. https://community.arubanetworks.com/home 



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