UNSOLVED
loop despite running stp protocol
Hi , hi, we have recently had a problem with network loops despite running stp - rstp protocol.
I don't have much experience with dell switches. I usually worked on extreme or cisco. and there it was usually enough to turn on stpd globally and run on the port to disable some redundant port. It's probably a bit different here.
an unmanageable switch was connected to ports 6 and 8, which resulted in the change of the root bridge and the triggering of a loop. I wonder why the stp mechanism did not block any of the ports?
logs :
<189> Jan 13 17:20:10 SW_AC106-1 TRAPMGR[trapTask]: traputil.c(721) 1115922 %% Instance 0 has elected a new STP root: 0080:4cd9:8fed:axxy
<189> Jan 13 17:20:10 SW_AC106-1 TRAPMGR[trapTask]: traputil.c(721) 1115921 %% Instance 0 has elected a new STP root: 0080:f48e:384a:xxxx
<189> Jan 13 17:20:10 SW_AC106-1 TRAPMGR[trapTask]: traputil.c(721) 1115920 %% Unit 1 elected as the new STP root
<189> Jan 13 17:20:10 SW_AC106-1 TRAPMGR[trapTask]: traputil.c(721) 1115919 %% Po1 is transitioned from the Forwarding state to the Blocking state in instance 0
configuration stp :
Spanning Tree: Enabled - BPDU Flooding: Disabled - Portfast BPDU Filtering: Disabled
Mode: rstp
CST Regional Root: 80:00:F4:8E:38:4A:BX:XX
Regional Root Path Cost: 0
ROOT ID
Priority 0
Address F48E.384A.AXXX
Path Cost 20000
Root Port Po1
Hello Time: 2s Max Age: 20s Forward Delay: 15s Transmit Hold Count: 6s
Bridge Max Hops: 20
Bridge ID
Priority 32768
Address F48E.384A.B0DF
Hello Time: 2s Max Age: 20s Forward Delay: 15s
Interfaces
Name State Prio.Nbr Cost Sts Role Restricted
--------- -------- --------- --------- ---- ----- ----------
Gi1/0/1 Enabled 128.1 0 DIS Disb No
Gi1/0/2 Enabled 128.2 0 DIS Disb No
Gi1/0/3 Enabled 128.3 0 DIS Disb No
Gi1/0/4 Enabled 128.4 200000 FWD Desg No
Gi1/0/5 Enabled 128.5 0 DIS Disb No
Gi1/0/6 Enabled 128.6 0 DIS Disb No
Gi1/0/7 Enabled 128.7 0 DIS Disb No
Gi1/0/8 Enabled 128.8 0 DIS Disb No
Gi1/0/9 Enabled 128.9 20000 FWD Desg No
Gi1/0/10 Enabled 128.10 0 DIS Disb No
Gi1/0/11 Enabled 128.11 0 DIS Disb No
Gi1/0/12 Enabled 128.12 20000 FWD Desg No
Gi1/0/13 Enabled 128.13 0 DIS Disb No
Gi1/0/14 Enabled 128.14 0 DIS Disb No
Gi1/0/15 Enabled 128.15 0 DIS Disb No
Gi1/0/16 Enabled 128.16 20000 FWD Desg No
Gi1/0/17 Enabled 128.17 0 DIS Disb No
Gi1/0/18 Enabled 128.18 0 DIS Disb No
Gi1/0/19 Enabled 128.19 20000 FWD Desg No
Gi1/0/20 Enabled 128.20 0 DIS Disb No
Gi1/0/21 Enabled 128.21 0 DIS Disb No
Gi1/0/22 Enabled 128.22 0 DIS Disb No
Gi1/0/23 Enabled 128.23 20000 FWD Desg No
Gi1/0/24 Enabled 128.24 0 DIS Disb No
Te1/0/1 Enabled 128.25 0 DIS Disb No
Te1/0/2 Enabled 128.26 0 DIS Disb No
Po1 Enabled 96.650 20000 FWD Root No
Po2 Enabled 96.651 20000 FWD Desg No
Po3 Enabled 96.652 0 DIS Disb No
Po4 Enabled 96.653 0 DIS Disb No
Po5 Enabled 96.654 0 DIS Disb No
Po6 Enabled 96.655 0 DIS Disb No
Po7 Enabled 96.656 0 DIS Disb No
Po8 Enabled 96.657 0 DIS Disb No
Po9 Enabled 96.658 0 DIS Disb No
Po10 Enabled 96.659 0 DIS Disb No
Po11 Enabled 96.660 0 DIS Disb No
Po12 Enabled 96.661 0 DIS Disb No
Po13 Enabled 96.662 0 DIS Disb No
Po14 Enabled 96.663 0 DIS Disb No
Po15 Enabled 96.664 0 DIS Disb No
Po16 Enabled 96.665 0 DIS Disb No
Po17 Enabled 96.666 0 DIS Disb No
Po18 Enabled 96.667 0 DIS Disb No
Po19 Enabled 96.668 0 DIS Disb No
Po20 Enabled 96.669 0 DIS Disb No
Po21 Enabled 96.670 0 DIS Disb No
Po22 Enabled 96.671 0 DIS Disb No
Po23 Enabled 96.672 0 DIS Disb No
Po24 Enabled 96.673 0 DIS Disb No
Po25 Enabled 96.674 0 DIS Disb No
Po26 Enabled 96.675 0 DIS Disb No
Po27 Enabled 96.676 0 DIS Disb No
Po28 Enabled 96.677 0 DIS Disb No
Po29 Enabled 96.678 0 DIS Disb No
Po30 Enabled 96.679 0 DIS Disb No
Po31 Enabled 96.680 0 DIS Disb No
Po32 Enabled 96.681 0 DIS Disb No
Po33 Enabled 96.682 0 DIS Disb No
Po34 Enabled 96.683 0 DIS Disb No
Po35 Enabled 96.684 0 DIS Disb No
Po36 Enabled 96.685 0 DIS Disb No
Po37 Enabled 96.686 0 DIS Disb No
Po38 Enabled 96.687 0 DIS Disb No
Po39 Enabled 96.688 0 DIS Disb No
Po40 Enabled 96.689 0 DIS Disb No
Po41 Enabled 96.690 0 DIS Disb No
Po42 Enabled 96.691 0 DIS Disb No
Po43 Enabled 96.692 0 DIS Disb No
Po44 Enabled 96.693 0 DIS Disb No
Po45 Enabled 96.694 0 DIS Disb No
Po46 Enabled 96.695 0 DIS Disb No
Po47 Enabled 96.696 0 DIS Disb No
Po48 Enabled 96.697 0 DIS Disb No
Po49 Enabled 96.698 0 DIS Disb No
Po50 Enabled 96.699 0 DIS Disb No
Po51 Enabled 96.700 0 DIS Disb No
Po52 Enabled 96.701 0 DIS Disb No
Po53 Enabled 96.702 0 DIS Disb No
Po54 Enabled 96.703 0 DIS Disb No
Po55 Enabled 96.704 0 DIS Disb No
Po56 Enabled 96.705 0 DIS Disb No
Po57 Enabled 96.706 0 DIS Disb No
Po58 Enabled 96.707 0 DIS Disb No
Po59 Enabled 96.708 0 DIS Disb No
Po60 Enabled 96.709 0 DIS Disb No
Po61 Enabled 96.710 0 DIS Disb No
Po62 Enabled 96.711 0 DIS Disb No
Po63 Enabled 96.712 0 DIS Disb No
Po64 Enabled 96.713 0 DIS Disb No
Po65 Enabled 96.714 0 DIS Disb No
Po66 Enabled 96.715 0 DIS Disb No
Po67 Enabled 96.716 0 DIS Disb No
Po68 Enabled 96.717 0 DIS Disb No
Po69 Enabled 96.718 0 DIS Disb No
Po70 Enabled 96.719 0 DIS Disb No
Po71 Enabled 96.720 0 DIS Disb No
Po72 Enabled 96.721 0 DIS Disb No
Po73 Enabled 96.722 0 DIS Disb No
Po74 Enabled 96.723 0 DIS Disb No
Po75 Enabled 96.724 0 DIS Disb No
Po76 Enabled 96.725 0 DIS Disb No
Po77 Enabled 96.726 0 DIS Disb No
Po78 Enabled 96.727 0 DIS Disb No
Po79 Enabled 96.728 0 DIS Disb No
Po80 Enabled 96.729 0 DIS Disb No
Po81 Enabled 96.730 0 DIS Disb No
Po82 Enabled 96.731 0 DIS Disb No
Po83 Enabled 96.732 0 DIS Disb No
Po84 Enabled 96.733 0 DIS Disb No
Po85 Enabled 96.734 0 DIS Disb No
Po86 Enabled 96.735 0 DIS Disb No
Po87 Enabled 96.736 0 DIS Disb No
Po88 Enabled 96.737 0 DIS Disb No
Po89 Enabled 96.738 0 DIS Disb No
Po90 Enabled 96.739 0 DIS Disb No
Po91 Enabled 96.740 0 DIS Disb No
Po92 Enabled 96.741 0 DIS Disb No
Po93 Enabled 96.742 0 DIS Disb No
Po94 Enabled 96.743 0 DIS Disb No
Po95 Enabled 96.744 0 DIS Disb No
Po96 Enabled 96.745 0 DIS Disb No
Po97 Enabled 96.746 0 DIS Disb No
Po98 Enabled 96.747 0 DIS Disb No
Po99 Enabled 96.748 0 DIS Disb No
Po100 Enabled 96.749 0 DIS Disb No
Po101 Enabled 96.750 0 DIS Disb No
Po102 Enabled 96.751 0 DIS Disb No
Po103 Enabled 96.752 0 DIS Disb No
Po104 Enabled 96.753 0 DIS Disb No
Po105 Enabled 96.754 0 DIS Disb No
Po106 Enabled 96.755 0 DIS Disb No
Po107 Enabled 96.756 0 DIS Disb No
Po108 Enabled 96.757 0 DIS Disb No
Po109 Enabled 96.758 0 DIS Disb No
Po110 Enabled 96.759 0 DIS Disb No
Po111 Enabled 96.760 0 DIS Disb No
Po112 Enabled 96.761 0 DIS Disb No
Po113 Enabled 96.762 0 DIS Disb No
Po114 Enabled 96.763 0 DIS Disb No
Po115 Enabled 96.764 0 DIS Disb No
Po116 Enabled 96.765 0 DIS Disb No
Po117 Enabled 96.766 0 DIS Disb No
Po118 Enabled 96.767 0 DIS Disb No
Po119 Enabled 96.768 0 DIS Disb No
Po120 Enabled 96.769 0 DIS Disb No
Po121 Enabled 96.770 0 DIS Disb No
Po122 Enabled 96.771 0 DIS Disb No
Po123 Enabled 96.772 0 DIS Disb No
Po124 Enabled 96.773 0 DIS Disb No
Po125 Enabled 96.774 0 DIS Disb No
Po126 Enabled 96.775 0 DIS Disb No
Po127 Enabled 96.776 0 DIS Disb No
Po128 Enabled 96.777 0 DIS Disb No
Do I have to select any specific options, e.g. bpdu protection?
I would not like to run port fast.
And how do you configure your feet on uplink? whether to run the loop protection option?
1084
0
Posted January 13th, 2022 13:00
Wojsal,
Thank you for waiting, the unmanaged switch has no ability to run STP, at least for the Dell switch that is. All unmanaged dummy switches should only have a SINGLE cable to the managed Dell switch. So thats where I would start.
Let me know what you see.
DELL-Chris H
Social Media and Communities Professional
Dell Technologies | Enterprise Support Services
#IWork4Dell
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Posted January 20th, 2022 04:00
hi sorry for the delay.
We have managed switches from the n2000 series and they have the stp configuration as shown in the screenshots provided.
950
0
Posted February 16th, 2022 01:00
The spanning-tree protocol is relying on understanding the topology by exchanging BPDU packets.
An unmanaged switch will not send any of them and that's why STP will not detect a switching loop through such device.
You may enable the "loop protection" feature which is working differently.
But be aware STP and loop protection should not be enabled at the same time on a switch port.
So you may enable loop protection for ports with STP-unaware devices connected.
DELL-Chris H
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1084
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Posted January 13th, 2022 13:00
Wojsal,
Let me research this for you and I will be back with you as sonn as possible.
Thank you for your patience.
DELL-Chris H
Social Media and Communities Professional
Dell Technologies | Enterprise Support Services
#IWork4Dell
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