Configuring Cisco switch stacks

malcybood

Just wondering if it is common place to configure Cisco switches as switch stacks (i.e. single mgmt address & global settings)?

I'm not as familiar with the higher end Cisco switches i.e. 3750, 4500 switches and wondered is it common place to configure these as a switch stack using "stackwise" functionality.

Also would these typically be configured as a stack through the CLI or using the CMS tool / Cisco Works?

I'm familiar with configuring other vendor LAN stacks but haven't ever had to do it on a Cisco switch. Can you stack 2950 switches if they have the correct IOS?

Does anyone have a sample config they could share in configuring a Cisco switch stack?

I've read through the config options on the 3750 management page but would like to see a config from a production switch if possible as not all of the options here are compulsary.

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.1_14_ea1/configuration/guide/swstack.html

Cheers
Malc

dtlokee

When you stack together 2 or more 3750's they appear to work as a single switch, the only thing that will give it away would be the port addressing (unless you go looking to see if it's a stack)

The ports will have an format of x/0/y where x is the switch in the stack and y is the interface, like Gi1/0/1 and Gi2/0/1. The only issues I have run into when stacking them is the stack order is determined by the mac address of the switch and if you mix the 3750-12G and other models you need to change the SDM template of the 3750-12G. "Show switch detail" will give you the details about the stack config.

As for the chassis style switches like the 4500 and 6500, it is managed as one switch and there is no stacking function. The ports will appear as "int x/y" where x is the slot and y is the port on the slot. In some cases you will see x/y/z where x is the slot, y is the sub slot adapter, and z is the interface.

It's not too bad really. The bigger issue with the 6500's is they don't really behave like a 3560 in the way they handle traffic and use hardware switching paths etc, they take some getting used to.

malcybood

Thanks dtlokee

dtlokee wrote: »

When you stack together 2 or more 3750's they appear to work as a single switch, the only thing that will give it away would be the port addressing (unless you go looking to see if it's a stack)

So is there no config required here then to make them operate as a stack? Does it achieve stacking using CDP or something and does the stack automatically change the newly added switch from member 1 default to i.e. member 2, 3, 4 etc in order of addition?

or

Would you require to login to the switch you want to be stack member 2 for example and issue the command in global config mode on the second switch?

switch current-stack-member-number renumber new-stack-member-number
reload slot stack-member-number

Just trying to get my head around how to configure a switch as switch stack member 1 - 9 or if this is automatically done when you connect the hardware.

dtlokee wrote: »

The ports will have an format of x/0/y where x is the switch in the stack and y is the interface, like Gi1/0/1 and Gi2/0/1. The only issues I have run into when stacking them is the stack order is determined by the mac address of the switch and if you mix the 3750-12G and other models you need to change the SDM template of the 3750-12G. "Show switch detail" will give you the details about the stack config.

I've had similar problems with other vendors. This appears not to be a huge issue at face value but for support purposes it can be a real headache when managing switch stacks remotely via SNMP GUI software i.e. if your logical representation in the SNMP tool is

Switch 1 (master)
Switch 2
Switch 3

but the physical switch stack is racked and cabled as below it can be confusing when dealing with field engineers who are on site or users!

Switch 2
Switch 3
Switch 1 (master)

dtlokee wrote: »

As for the chassis style switches like the 4500 and 6500, it is managed as one switch and there is no stacking function. The ports will appear as "int x/y" where x is the slot and y is the port on the slot. In some cases you will see x/y/z where x is the slot, y is the sub slot adapter, and z is the interface.

It's not too bad really. The bigger issue with the 6500's is they don't really behave like a 3560 in the way they handle traffic and use hardware switching paths etc, they take some getting used to.

Ah ok I typo'd above with the 4500, forgot that was a chassis based switch. I'm not too bad with those, or the concept isn't really any different to the switches we use at the core/distribution layer.

dtlokee

The 3750's use a stacking cable o nthe back to make them a stack, when you connect them it makes the stack, no configuration required. I would recommend connecting them in the correct order (I think it's based on the higest MAC address is the first switc, second highest is the second switch) to eliminate the need to use the "swap" command to make the interfaces match the physical layout.