I was recently asked “How to cascade a stack of Nortel switches?”. I thought that’s a pretty easy question but probably one that hasn’t been covered well by the manuals or other material. In short you just need to physically connect the switches using the supplied cascade/stack cables. On the back of each switch you’ll find a selector switch with two options, “Base” and “non-Base”. Only one switch in the stack can be set to Base and I generally set the topmost switch (physically looking at the stack) to the Base switch. That’s really all there is to it, the software will detect the presence of the cascade/stack cables and the switches will each join the stack, numbering themselves as “Unit 1 – Base”, “Unit 2″, “Unit 3″, and so on. The ports will then be referenced as 1/1, 2/1, 3/1, etc.
There are of course some caveats, aren’t there always caveats!. You can only stack specific switches with themselves. For instance you can only stack a Nortel Ethernet Routing Switch 5500 series switch (5510, 5520, 5530) with anther Nortel Ethernet Routing Switch 5500 series. You can’t stack a Nortel Ethernet Routing Switch 4500 series with a Nortel Ethernet Routing Switch 5500 series. The stack cables are very different so it shouldn’t be too hard to figure out. The switches must have the same software version of code on them in order to stack properly. The newer Ethernet Routing Switch 4500/5500 series switches will try to automatically upgrade any switch that is added to the stack and isn’t running the appropriate software version.
You can cascade/stack older Ethernet Switch 450, Ethernet Switch 460 and Ethernet Switch 470 switches. I would not advise stacking the Ethernet Switch 450 with either the ES460 or ES470 even though Nortel claims you can. There’s no issue stacking a Nortel Ethernet Switch 460 with the Ethernet Switch 470.
Cheers!
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#1 by Tom on August 10, 2008 - 7:25 pm
“The newer Ethernet Routing Switch 4500/5500 series switches will try to automatically upgrade any switch that is added to the stack and isn’t running the appropriate software version.”
We have tried this, but thus far does not work in the two instances we have tested. We have Unit Unit Replacement enabled and run the secure image versions of both the ERS 4500 and 5500 software.
Will have to do some more troubleshooting of this…
#2 by Michael McNamara on August 10, 2008 - 7:32 pm
Hi Tom,
I’ve personally seen an Ethernet Routing Switch 5520 stack upgrade a new switch that was added to the stack. I believe the switches need to have software v4.2 or higher. Well actually now that I’m thinking about it, the stack actually downgraded the new switch that I added to the stack. I haven’t actually tested a 4500 series switch yet.
I’ll perform another test using the secure image and post the results here.
Thanks for the comment!
#3 by Curtis on August 20, 2008 - 2:19 pm
I will be adding new 5520 switches to existing single switches to start a stack at two locations in the next few weeks, so I will also see how the auto update feature works.
What I wonder is if the base switch was set on the switch with the higher version?
Also, on a side note, I am wondering if anyone is having problems with the 5520 switch ip address source parameter mysteriously changing on its own? I’ve had several instances where this parameter either changes during a software upgrade, or…just changes for no reason (turning on BootP/DHCP – it should be set for configured source or off at all times). All of my switch access and config changes are monitored thru Opsware, so I know that the parameter was not changed through other means. I have seen this occur on several ERS 5520 switches running either 5.0.x or 5.1.1 software.
#4 by alphaalpha1 on October 30, 2008 - 3:17 pm
Hi,
I am new to this Site and also to Nortel as well, If anyone can help me or guide me to proper direction, I would be really thankful to him.
Here is the scenario.
We have around 7 Nortel 5500 series switch. One default VLAN, one subnet.
Sw 1 to 5 are cascaded to each other through SCSI cable. Same with Sw 7 & 8.
Sw 1 & 7 are connected through one ethernet LAN cable.
I need to accomplish:- (Also need your Advice / direction)
Configure Trunking between sw 1-7 & 5-8 by reserving four ports on each switch.
We do not want to create VLANs at all.
I also read somewhere instead of Trunking, configuring Ethernet access port is better bet.
So guys you tell me what is best way and how to achieve that.
Thanks in advance.
#5 by Michael McNamara on October 30, 2008 - 8:59 pm
Hi there,
The answer is really simple. Just connect each stack to the next stack with a single CAT5/CAT6 patch cable. Since you are running only one VLAN there’s no need to configure a trunk port or do anything else.
Just as a quick note it’s not a SCSI cable but a proprietary cascade cable from Nortel. It’s referred to as the stacking cable or cascade cable.
You might just want to make sure you enable Spanning Tree Protocol, which is enabled by default if you haven’t changed anything. STP will help prevent any loops from bringing down your network.
Good Luck!
#6 by Semion on February 18, 2009 - 2:44 am
How i can add one 470 switch to existing stack of four switches ?
I understand i need to upgrade firmware to exactly level as rest of stack and put dip switch to non-base mode, besides that doi need to make more configurations and do i need to reset all stack and request downtime for users?
#7 by Michael McNamara on February 18, 2009 - 3:49 pm
Hi Semion,
As long as the switches are all running the same software and firmware (diagnostics boot code) you can just break the stack (cables) and add the new switch to the bottom of the existing stack. You’ll want to make sure that there are no alarms on the stack/cascade ports before you do this or you might take the switch down when you break the stack. After the switch boots up it will automatically be added to the switch stack as the next unit in the stack.
Thanks for the question!
#8 by Semion on February 19, 2009 - 1:34 am
Thank you very much
#9 by Nortel Newbee on November 4, 2009 - 10:59 am
Hi all, I don’t know if this is exactly the perfect time to get thrown into a Nortel enviroment because of the recent uncertaintly of Nortel but here I am. Can’t compain, at least I have a job (for now). Great site and I will be refering to it regularly for tips and suggestions. My company will soon be integrating VIOP to our sites (30). Any suggestions or resources pertaining to this subject matter, thanks.
#10 by Michael McNamara on November 6, 2009 - 2:24 pm
Hi!
You should find quite a bit of information here and some additional information over on the fourms. I’ve already created links in the FAQ topics to some of the more important technical configuration guides.
Good Luck!