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If the network admin chooses not to “clean up” the configuration after a member has been removed, the

configuration will remain the running-config and the startup-config for the stack. This extra configuration will make

the configuration file “config.text” larger than it should be.

In a switch replacement situation, replacing a member switch with an identical model is very convenient with

FlexStack stacking. FlexStack remembers the member model number, but not the MAC address. During a switch

replacement, if the old member is replaced by the same Cisco Catalyst 2960-S, 2960-X, or 2960-XR model, when

the new switch is inserted into the FlexStack stack, it will inherit the configuration of the previous member. If the

new switch model does not exactly match the replaced switch, the old configuration is not used. If there is room in

the stack for a new member, then the new switch is added to the stack. If the stack size is at the maximum, then

the configuration for the replaced member is removed.

Replacing a master switch needs one additional item to be clarified. The switch priority (configured with the

command “switch X priority Y”) is not stored in the running-config or the startup-config. When the replacement

switch is placed into the stack, it will not inherit the switch priority. The new switch will have the default priority of 1.

To make the new switch the master, the network administrator must configure the new switch to have a higher

priority than any other member. The existing master must be rebooted (or the entire stack must then be rebooted)

after this configuration to force a master change. Just configuring the priority to the new member is not enough to

trigger a master change. If the entire stack was rebooted, the newly added switch with the highest priority will be

the stack master. If only the master is rebooted, the existing members will have a master election. The switch with

highest priority will become stack master. The old master will reboot and join the stack as a member.

Upgrading the Cisco IOS Software Release on a Stack

FlexStack has the capability to upgrade all members with a single command. A single command eases the

operational burden on the network administrator. The command to initiate an upgrade takes place on the master.

The master makes sure that each member is properly upgraded.

The Cisco IOS Software CLI command to upgrade a FlexStack stack is:

“archive download-sw [options] <source-file>.”

The default behavior is to upgrade all members.

The options for the ‘archive download-sw’ command allow for detailed control of the upgrade. Use the options

to update only a single member instead of the entire stack or to reload the stack after the upgrade is successful

instead of having the reboot be an extra step for the network admin.

The “source file” is a tar file downloaded from Cisco.com called an image file. The tar file can be copied over the

network using Trivial File Transfer Protocol (TFTP) or FTP. The most common and recommended way to upgrade

the stack of switches is using TFTP. The network admin should copy the tar file with the desired Cisco IOS

Software image to a TFTP server in the network. In the ‘archive download-sw‘ command, use the IP address

of the TFTP server and the name of the image file as the source file. No destination file name is necessary.

Here is an example of using the ‘archive download-sw‘ command to upgrade a stack of Cisco Catalyst 2960-S

switches. Notice that the number of members in the stack is not relevant to this command. By default all members

are upgraded unless the network admin uses the options to do otherwise. The TFTP IP address is 192.168.1.1,

and the tar file name is c2960s-universalk9-tar.122.53.SE.tar.

C2960-48# archive download-sw tftp://192.168.1.1/c2960s-universalk9-tar.150-2.SE3