Cisco 3850 Stacks

[Zachary Ballard]

So I am stacking two separate 3850 Stacks together. They are in separate buildings. I am using sfp ports, both stacks have NM4-1G modules. I am configuring one link between the two and cannot get any data to pass between the two.

The links show up/up, the Lights on both ends are green, If i shutdown one side, the other side goes down aswell. However, the switches are not discovering eachother via cdp and it is enabled. This is really odd. Both ends have a simple "switchport mode trunk" command configured. Any ideas?? 

Thanks!

[Reza Sharifi]

Can you post "sh run" from both switches and point out the interface number connecting them together? 

If you are using the 1Gig fiber port, it should be gi1/1/x

HTH

[Zachary Ballard]

I recently switched jobs so I haven't been logged on here in a bit. I wanted to update this thread with the solution to my problem.

To recap, I was having an issue with trunking two switch stacks together. This simple task had me beat for two days. No matter the configuration, the two switches would not form a trunk. On the second day I finally decided to check the mac address table to see what mac address the switch was listing for the trunked port. This is when I found that the switch was not listing any mac addresses. This issue was caused by a Bug and after updating the code on these switches they worked perfectly. I am writing this from memory so I do not remember the specific bug #.

[Mark Malone]

thanks for updating the fix if you have the software version you seen this on please add it to the thread , it will help someone