A 2 Switch Scenario

theseman

Hello everyone, was hoping someone has run into this before (or at least has heard of it)

The Setup:
-Two 2950 Switches (both with IOS 12.1 or later) (I'll call them S1 and S2)
-Switches are connected by two crossover cables for redundancy (S1 FA2--S2 FA2 and S1 FA3 - S2 FA3).
-Spanning tree is set to default mode (pvst)
-Left priorty to defaults, so lowest mac was selected as root (S1)

So heres the problem: Using the sh spanning-tree command on S1 - all ports fwding (as expected). Using the command on S2, FA3 was set to alternate - blocking (also as expected). However, link light does not change to amber. Using a 2950 and an older switch, same results, only the light goes amber. Is this expected?

bmauro

I *believe* that on my switches ports that were in blocking mode were still green. I can't be 100% sure, but I did spend quite a bit of time on STP and that is the best I can remember.

theseman

Thanks for the reply, what model of switch did you use?

bmauro

(2) 2950
(1) 3550

I can test this tonight if no one else answers - but to the best of my memory my blocking ports were still green.

theseman

You don't have to go out of your way to test it out for me!! But thank you all the same!! I am going to try a bit bigger setup today, with a couple more switches to see if I can figure it out.

pr3d4t0r

theseman

Well today I tried a 4 2950 switch setup, redundant paths et all. While some ports are classified as blocking in a sh spanning-tree, the LEDs stayed green.

Once again, I switched one of the 2950s for a 2820 and the LEDs on the blocking ports turned amber.

Who knows!

Netwurk

On some models, the ports will go amber with a 10Mbps link and green with a 100Mbps link. The 2820 is an old model with 10Mbps ports, so that may be your answer

theseman

Netwurk-

That is not an answer I had really considered!! I tried different STP modes, redundant paths like you wouldn't believe, among other things. I did quite a bit of searching on the issue and had yet to come up with a reasonable cause.

Thanks for easing my mind, issues like that are ones that I need an answer to! lol