Stacking - adding nodes and blocked links

  • 7 January 2014
  • 3 replies

Userlevel 4
Create Date: Sep 12 2012 2:13PM

Hi all,

Apologies if these questions appear elsewhere - I couldn't find them in a search.

I have two stacks, currently 2 switches each. One is X650-24t & X460-48t, the other is 2 x X460-48t. All switches are running XOS I have them stacked with the SummitStackV80 module and QSFP cables (obviously a 4x40G card in the X650).

1) I'm having problems adding switches to the stack - I have been through the instructions in the 15.1 Concepts Guide, but the links are just reporting as "No Neighbor". I was led to believe I could add switches without having to reboot the whole stack - is this not the case? There was an error in the log on the new switch complaining about the stack MAC address - to experiment I ran a configure stacking mac-address and rebooted. The error went but still no joy. Any ideas?

2) In the working 2-switch stacks, one link is marked as "Blocked". I believe from the documentation that in the event of an equidistant path between two switches (e.g. in a 2-switch stack) both links will be used, one for ports 1-24 and 1 for ports 25-48. Is this not the case?


Laurence (from Laurence_Pawling)

3 replies

Userlevel 4
Create Date: Sep 12 2012 5:32PM

Hello LaurenceFor the most part adding a switch to an existing stack is very easy essentially turn on the new switch, connect it to the stack and then enable stacking (Careful not to say yes to the easy stack question) once that is done reboot the new node and it should come up into the stack. This assumes that the code is the same as the other switches and I would recommend making sure it is in the same image container which will remove issues going forward.If the switch comes up and is not part of the stack and it reports itself as slot 1 then just go into the master of the stack and use the command config stacking node-address slot-number then reboot the new switch. The master should tell the new switch to be a slot and things should be okay.Let us know if this helps.P (from Paul_Russo)
Userlevel 4
Create Date: Sep 13 2012 11:18AM

Thanks - I've found what the problem is.

In addition to the settings mentioned in the Concepts guide, it seems you also need to run:

configure stacking protocol enhanced

Doing this and then rebooting made the switch instantly visible to the main stack and I could then synchronise the config.

Interestingly though I'm still seeing one of the links showing as Blocked - I was under the impression that Slot 1 would be able to communicate directly with Slot 3 without having to go via Slot 2?


Laurence (from Laurence_Pawling)
Userlevel 4
Create Date: Sep 13 2012 12:13PM

Hey Laurence Yep that would do it sorry wasn't sure which switch you were adding. There will always be a blocked port but that port is only blocked for broadcast/multicast/ and unknown packets. Unicast packets will go over both links and are not blocked.ThanksP (from Paul_Russo)