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Adding a third switch to an existing stack? 1

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rpma

IS-IT--Management
Dec 17, 2010
4
US
Currently I have two cisco 3750 switches that are connected with two Stackwise cables. The typical cross connection for two Cisco 3750 poe 42 switches. I want to add a third switch. I know how to connect them but want to see if I am going about it the right way. (After the connection are made the switches will be in the standard Cisco Stackwise cable configuration for three switches)

The current connections are:
Switch 1 Stack1 port to - Switch 2 Stack2 port
Switch 2 Stack1 port to - Switch 2 Stack1 port

With the stack running, can I disconnect the Stackwise cable from switch 1 stack port 1 and connect it to the new powered off Switch 3 stack port 1 and then add a new Stackwise cable between switch 1 stack port 1 to switch 3 stack port 2? Then power on the new switch?

The second cable between the original switches will not be disconnected at any point. I believe doing it this way may just reduce the bandwidth temporarily and will maintain network connectivity of the two switches.

Will this allow the original stack to continue to have network connectivity while I reconfigure the Stackwise cable and add the new one?

When the new switch is turned on will it then be added to the stack as the third member? It is running the same version.

let me know if you need any clarifications.
 
You configuration will work fine. As long as the IOS version is the same you'll be good to go. Make sure you understand the effect this may have on electing the stack master. Have you manually configured the stack member priority of any of the switches??

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)
 
You've messed up your description of how your stack cables are connected, but your stack cables should go like this:

- remove Sw1 port2 <----> SW2 port1
- this leaves you with Sw1 port1 <----> SW2 port2
- add Sw2 port1 <----> SW3 port2
- add Sw3 port1 <----> SW1 port2

If it's exactly the same version , it will join the stack very quickly.

Make sure the switch stack is logging to a syslog server and watch the log live while you join sw3 to the stack. This will show you what is happening.
 
Thanks,

Added switch and all went as planned.
 
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