Aruba Instant On Series - Stacking Switches

Good morning, so a year or so ago I setup a remote site using 2 Aruba 1960 24 Port switches because I liked the idea having the portal to manage them. During setup I installed 2 fiber cables from each switch, stacking them and adding link aggregation. Recently the company needed some expansion so I sent them a third 1960 and this is where the trouble began.

Original setup: SW1 Port 27 → Sw2 Port 27, SW1 Port 28 → SW2 Port 28. On the new setup I had them install the switch and wire as follows, SW1 Port 27 → SW3 Port 28, SW1 Port 28 → SW2 Port 27, SW2 Port 28 → SW3 Port 27. I added the new device to the inventory and this is where issues arise, as the new switch was installing its software for the first time, it dropped offline during the install but never came back. I ended up having a staff person connect a LAN cable from any port on the 3rd switch to switch one, the 3rd switch then came back online, but removing that LAN cable would male the switch go offline. From there its been a pain, and have had terrible support from Aruba for nearly 3 weeks now trying to resolve the issue. 2 weeks ago I had a tech on site and had him swap around the new 10G transceivers to see if maybe a transceiver was bad, upon rebooting, switch 2 went offline and switch 3 came online, I ended the troubleshooting having the tech install the original modules into SW1 and SW2 and get my stack back working. I sent the aruba transceivers back and ordered 3 DAC cables and this past week, I had them install the DAC cables and SW2 went offline and SW3 came online. Sorry for such a long explanation just to get to my question, one thing I missed is I never deleted the Link Aggregation during all this troubleshooting and with Aruba wanting to RMA switch 2 I don’t think its a hardware issue but a configuration issue, I am thinking the LA is causing the problem most likely. I’m not running any redundant cabling like I was on the 2 switch stack . What do you think? This is a production environment so I’m trying to be careful to keep the company functioning so hesitant to make drastic moves.

This sounds like switch 2 and switch 3 are configured with the same stack ID.

Well originally when I used a LAN cable between Switch3 and Switch 1 to get the switch online to manage, I was able to add switch 3 to the stack and as a Member but as soon as the LAN cable was removed the switch went offline. I have since unstacked all the switches to troubleshoot but all 3 switches do have link aggregation setup, which I feel is possibly the culprit. As I say the Aruba support as been dismal at best, they haven’t even offered to have a remote session so they can at least view the devices in the Aruba Portal.

By “link aggregation” do you mean for the stacking ports? If so, that sounds wrong to me - I haven’t used the 1960 series but in every other Aruba and other vendor I’ve touched, ports used for stacking should have no configuration on them at all. When you just had two switches and they were directly connected that was fine, but now with a ring topology the two ports aren’t connecting to the same device on the other end.

Correct, if you want redundant connections on the stack you setup Link Aggregation on those ports.

That’s certainly different from the old Cisco, Enterasys, and my new Extreme switches for stacking in a loop. The switches then decide how they will send packets over the loop with special cases of STP, etc.

If it is aggregating the ports, then you can’t make a ring/loop, and you can’t really cascade the ports as aggregated because they aren’t aggregated in a 3 switch system.

This post suggests you do this in the ring/loop mode:

https://community.arubainstanton.com/blogs/gregory-weaver1/2022/04/20/1960-stacking-guide

sw1 28 → sw2 27
sw2 28 → sw3 27
sw3 28 → sw1 27

and when the software is configured for stacking, it’s just supposed to work. This is roughly how all the other switches I’ve used get connected in a stack. You don’t have to connect the loop back up to the top, but then the switch only has a single path it can go which may not be the shortest or fastest.

After that, I know nothing more about these switches.

Correct, yes the stacking ports are exactly as follows, when the stack was first created with only 2 switches only one set of fiber was used. I added a second fiber to give some redundancy before shipping out. This is where LAG was used to combine the now 2 fibers.

So after some time going back and forth with Aruba support in the end, I was initially correct and Link Aggregation was the cause of my issues. As soon as I started deleting the LAG members my second switch came back online and was able to get the stack sorted. However there is one glitch at the moment, with the 3 switches connected in the recommended ring topology from Aruba I am getting a loop detection error on SW3 Port 27 which doesn’t affect the overall condition but trying to confirm with Aruba if this is a normal state when in this configuration.