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Adding 4th Cisco 2960S Switch to Stack

Posted on 2014-04-13
Medium Priority
Last Modified: 2014-04-18
I currently have a stack of 3 Cisco 2960S switches connected together.  I'd like to connect a fourth 2960S which is exactly the same except maybe the Software .....  I've not checked yet.

What is the process of doing this ?

Thanks ...
Question by:jtbrown1111
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1 Comment

Accepted Solution

gcl_hk earned 2000 total points
ID: 39998475
Adding Members to an Existing Stack

The relative ease with which new members can be dynamically added to an existing stack is a real strength of FlexStack. A brand new switch added to an existing stack will join as a member. The new member will be given the next available member number. When a new member is added to a stack, it will be rebooted to clear any configuration it might have. When the new member completes the reboot it will have the configuration of the stack.

It is recommended that FlexStack operate in a fully redundant mode. In order to add a member to an existing stack, at least one FlexStack link must be disconnected, causing the existing stack to operate in nonredundant mode. This disconnection will cause a minor traffic outage across the stack. Traffic will resume while the stack is in nonredundant mode. The network administrator does not need to connect the FlexStack link in a fully redundant mode for traffic to flow. When the FlexStack links return to a fully redundant mode, there will be another minor traffic outage across the stack. Network administrators should try to limit the number of FlexStack link operational changes to decrease the amount of traffic disruption.

Cisco Catalyst 2960-S switches do not need to be powered off to join a stack. However, when a new member joins an existing stack, the new member will be rebooted anyway to clear its configuration . The new member is automatically rebooted by the stack. A reboot is operationally equivalent to powering a switch off and then on again. Thus, it is a better practice to add new stack members to an existing FlexStack powered off.
The following are steps for adding a new member to an existing stack, and it is desired that the new member not become the master. In a rack deployment, new switches are typically added at the top or the bottom of an existing FlexStack. This example will show how to add switches to the bottom of an existing stack of switches.  

1. Place the new switch in its final location. Do not insert the power cord. To minimize downtime, complete all cabling that would be required of any switch placed into production at this time.

2. Insert the FlexStack module in the back of the new member.

3. Disconnect the FlexStack cable from the existing member just above to the new member. This would be the cable that is connecting the bottom member with the top member. You will need this to connect the new member located at the bottom of the stack to the member at the top.
a. When the FlexStack cable is disconnected, this is when the stack enters into a nonredundant mode.

4. Connect the new member with a FlexStack cable to the member just above. The FlexStack port used to connect one member to another is not important. Stack members should be connected to each other any way that makes cable management easiser for the network administrator.

5. Connect another FlexStack cable to the member at the top. Make sure that all cables are connected properly. A light tug on the FlexStack cable will make sure that it is properly seated.

6. Connect the AC power cord to the new member. It will power on. It will take a few minutes for the new member to complete the boot process.

7. The new member will join the existing stack.
a. When the new member completes the boot process, this is when the stack enters into a fully redundant mode once again.

8. All the FlexStack links will be operational if all the connections were made properly.
FlexStackIf all went well, traffic on the exiting members was minimally interrupted. There were at least two interruptions. The first occurred when the FlexStack cable was removed in step 3. The other interruption occurred when the new switch joined the stack after being powered on (step 7). In between the two interruptions, traffic will continue to be switched over the existing members and the operational FlexStack links.

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