STP Light Status

redgoblinredgoblin MemberMember Posts: 57 ■■□□□□□□□□
Hi all,

Correct me if I'm wrong but I always thought that blocked STP ports were always Amber, but after playing around with STP in my home lab I've noticed that the only Amber ports that actually show are any blocked ports connecting to the Root Bridge - The blocked ports on the segments not connected to the Root Bridge should in theory be Amber as well but they're all green?? Does anyone have an explanation for this?

Comments

  • tech-airmantech-airman Senior Member Member Posts: 953
    redgoblin wrote:
    Hi all,

    Correct me if I'm wrong but I always thought that blocked STP ports were always Amber, but after playing around with STP in my home lab I've noticed that the only Amber ports that actually show are any blocked ports connecting to the Root Bridge - The blocked ports on the segments not connected to the Root Bridge should in theory be Amber as well but they're all green?? Does anyone have an explanation for this?

    redgoblin,

    Which model switch are you talking about?
  • redgoblinredgoblin Member Member Posts: 57 ■■□□□□□□□□
    This happens on a 2950-12, 2950-24, and a 3550-PoE.

    Weird thing is, on each of the switches above, the redundant connections directly to the Root Bridge show as Amber, but the the blocked ports on Segments not connected to the Root Bridge show as Green rather than Amber.
  • dtlokeedtlokee Village Idiot Member Posts: 2,378 ■■■■□□□□□□
    They will remain green if it's a trunk port because with PVST+ each VLAN can be blocked separately.
    The only easy day was yesterday!
  • redgoblinredgoblin Member Member Posts: 57 ■■□□□□□□□□
    Yeah I 'm guessing you're right about PVST+ - But what I don't understand is I'm only using VLAN 1 and in any case, if PVST+ shows Blocked Ports as Green due to the possibility of the same ports being Forwarding in other VLANs, the direct 'Alternate' Root Port connections should've showed as green as well (since there's every possibility they could be Forwarding in other VLANs), but they show Amber?

    Confused .. icon_confused.gif
  • dtlokeedtlokee Village Idiot Member Posts: 2,378 ■■■■□□□□□□
    Is it a trunk or access port?

    show interface fa x/y switchport
    The only easy day was yesterday!
  • redgoblinredgoblin Member Member Posts: 57 ■■□□□□□□□□
    All dot1q Trunks
  • ITdudeITdude Cisco Addict Member Posts: 1,181 ■■■□□□□□□□
    redgoblin wrote:
    All dot1q Trunks

    There you go.... icon_wink.gif
    I usually hang out on 224.0.0.10 (FF02::A) and 224.0.0.5 (FF02::5) when I'm in a non-proprietary mood.

    __________________________________________
    Simplicity is the ultimate sophistication.
    (Leonardo da Vinci)
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