The steps to stack Cisco’s 2960-S switches are generally the same so I won’t go into too much detail, but I wanted to shed some light on it just to provide some coverage for anyone that is looking to do this on their network. We will be going with three Cisco 2960-S switches.
The main components that you will need are: switches, stack modules and stack cables
Once you remove the stack module cover on the rear of the switch, you will of course have gaping holes that you will need to insert the modules into!
You can go ahead and plug in the stack cables and allow the switches to select the MASTER through an election process, or you can define which switch you’d like to be the MASTER by setting the priority to the highest level which is 15.
switch(config)# switch 1 priority 15
My switches are in order from top to bottom: 1, 2 and 3. (MASTER, MEMBER, MEMBER)
I’ve provided how the stack cables actually look when stacked based on Cisco’s diagram. This provides full duplex stacking.
*Notice the white/gray tabs on the stack cables. If the cables are on the top position, the tabs are on top. If they are connected on the bottom, the tabs are on the bottom!
If everything is done right, you can visually tell which switch is the MASTER by looking at the front display LED lights. Take a look at it below.
- 20Gbps Bandwidth – Just as I mentioned before, I don’t like the way the stacking speeds are advertised. As mentioned before in my Cisco Stacking 3750 switch blog, the displayed speeds is actually 10Gbps, but because it is full duplex, that’s how they arrived with 20Gbps.
- Management – When stacked, all your switches are logically one switch. One management IP address to manage all three switches.
- Cabling – Cleaner cabling since they stack from behind and would not interfere with any other cables you may have. So it is aesthetically pleasing.
- 4 Member Switch capacity – You can stack up to four switches in your Flexstack switching fabric. This gives you much room for growth and 192 Ethernet 10/100/1000 ports with 16 optional modules.
- Hot pluggable switches – You can remove and add switches while the stack is running. A working stack can accept new members or delete old ones without service interruption.
- FlexStack – Hardware drop table.
- Make sure your IOS versions are the same, if not, update each switch with the same IOS version before proceeding.
- All switches out of the box (if not stacked, meaning they are standalone) defaults to being their own MASTER.
- If you manually change the stack member number, you need to RELOAD that member switch in order for it to take effect. (hint: use the RELOAD SLOT command)
- Priorities range from 1 through 15. The higher the priority, the higher the chances of the member switch becoming the MASTER.
If you want to see the status of your stack ports.
Verify that your stack is connected at full duplex.
Verify that you have access to all your interfaces. (I’ve cut the output for brevity)
Verify all your switches are part of the stack and who your MASTER switch is.
FlexStack vs StackWise Plus
So what is the difference between the two “stacking” technologies from Cisco? Have a look at the chart below!