Dell PowerConnect 6224: Stacking Module Dual Master

Dell PowerConnect 6224: Stacking Module Dual Master

We use a couple of Dell PowerConnect 6224 switches in our storage network, however when they were first deployed we ran into an issue with the stacking modules. Basically when you brought up the switches they would both see themselves as master, and would not “stack” correctly. Turns out the solution was rather easy but not well documented.  Also as a side note, I have a friend with a couple of PowerConnect 6248 switches where he had the same issue.  So it appears this issue spans the whole family at least.

The core of this issue is that in the previous generation there was a 10g module and a separate stacking module.  With the current version they decided to simply have one module that is 10g or stacking, and you can set the mode to toggle between them, this of course is good for Dell, because it requires them to maintain smaller inventories, and also it is good for you because if your needs change you can re-purpose the same module for a completely different use-case.

I am not a “switch” guy, I find the stuff boring in most cases, however this was just an interesting enough issue with a simple enough fix that I decided to document the fix.  This article assumes that you know how to connect to the console of your switch and that you are familiar with the basics of configuring a switch.

Enter Enable Mode

> enable 

View Current Stack Configuration

# show stack-port
Configured  Running
Stack      Stack      Link       Link
Unit    Interface       Mode       Mode       Status     Speed (Gb/s)
---- ---------------- ---------- ---------- ------------ ------------
1    xg1              Ethernet   Ethernet   Link Down    Unknown
1    xg2              Ethernet   Ethernet   Link Down    Unknown
1    xg3              Ethernet   Ethernet   Link Down    Unknown
1    xg4              Ethernet   Ethernet   Link Down    Unknown    

Enter Configuration Mode

# config

Enter Stack Configuration Mode

(config)# stack

Change From Ethernet To Stack Mode

(config-stack)# stack-port 1/xg1 stack
(config-stack)# stack-port 1/xg2 stack
(config-stack)# exit

Verify New Stack Configuration

# show stack-port
Configured  Running
Stack      Stack      Link       Link
Unit    Interface       Mode       Mode       Status     Speed (Gb/s)
---- ---------------- ---------- ---------- ------------ ------------
1    xg1              Stack   Ethernet   Link Down    Unknown
1    xg2              Stack   Ethernet   Link Down    Unknown
1    xg3              Ethernet   Ethernet   Link Down    Unknown
1    xg4              Ethernet   Ethernet   Link Down    Unknown    

Once you are done with one wash, rinse, and repeat on the other switch(es), but one last thing to notice.  Here that we are showing two different modes, “configured stack mode” and “running stack mode” this is reflecting that we have made the configuration changes necessary to flip the modules over, but that the machine has not be rebooted so that it can reload its configuration.  So now when you have some downtime reboot the switches.  The first one that comes up will be the master and the second one will end up with a default configuration.  In our case the only configuration specific to our environment is jumbo frames.  Which can be configured switch wide.

Enter Enable Mode

> en

Enter Configuration Mode

# configure

Enter Interface Configuration Mode For All Ethernet Interfaces

(config)# interface range ethernet all

Enable Jumbo Frames

(config-if)# mtu 9216
(config-if)# exit

Well that does it.  You now have a stacked Dell PowerConnect with Jumbo Frames enabled.