3750X - Add a Switch and form a stack

[Ich Nafi]

Hello everyone,

I wanted to add a second 3750X to a currently running one. Both have the same IOS version. But after connecting the new one and powering it up, the old one does not recognize the newly connected.

 Switch #    Port 1       Port 2
  --------    ------       ------
    1          Down         Down

Do I really have to power cycle both at the same time, so they see each other? On 2960X I can add stackmembers on runtime.

Cheers!

[Joseph W. Doherty]

"Do I really have to power cycle both at the same time, so they see each other?"

No, normally all you need to do is power it on after connecting the stack cables.

How is the second 3750 configured? (Normally, I add them with an erased config.)

[Ich Nafi]

The second one has no config at all.

I also tried a reload of the old switch over night, but the stack ports are still down.

I also don't think that both stack cables are broken...

[Mark Malone]

have you reseated them just incase they didnt connect right , it may be a layer 1 issue

do the logs show anything when you connect the new switch at all regarding it ?

[Leo Laohoo]

The output shows the stacking cable isn't cabled up.

[Ich Nafi · Accepted solution]

I know, but they are, both. Tripple checked. Reseated them, no change.

Al right....grabbed some old 3750X and did a dry run.
1. Powered on 1st switch and waited till fully up

2. Connected stack cable and 2nd switch to it

3. Powered up the 2nd switch

4. After a few minutes, stack-link came up

Conclusion: Either both stack-cables or both stack-ports of one my production switches are broken...

Thanks for all the responds.

[Joseph W. Doherty]

Ah, good. (I.e., good you got results we would expect, not so good regarding there appears to a some hardware issues with your original pair.)

If you have "extra" 3750s, you can further mix and match to find the actual defective component(s), correct?