Rescuing a Stack that has No Master-Capable Node

It is possible for all nodes in a stack to have master-capability set to OFF. For example, if a stack was operating with no redundancy (for example, with one master-capable node) and the master node failed, all other nodes in the stack restart as standby nodes and there is no master node.

Another example is the case where you dismantle a stack before using the unconfigure stacking command or the unconfigure switch all command. In this case, the individual switches are configured for stacking, are not master-capable, and are isolated from a stack master.

In this situation, the only security information available is the failsafe account. If you know the failsafe user name and password, you can log into any node and reconfigure master-capability or redundancy. However, if you do not know the failsafe account information, there is another way you can change the configuration.

The procedure described here generally is not needed if another master-capable node is expected to rejoin the stack. If this procedure is used, it is possible that the new master will duplicate the master that is expected to rejoin later.

To assign a new master-capable node, follow these steps.

At the login prompt, enter the following special login ID exactly as displayed below (all uppercase letters) and press [Enter]:
REBOOT AS MASTER-CAPABLE
The following message appears:
```
Node reboot initiated with master-capability turned on.
```
This node then sets an internal indicator that is preserved across the reboot. While restarting, the node notices and resets this indicator, ignores the node master-capability configuration, and becomes a master node.

The special login ID described here is available only if all of the following conditions are met:
- The node supports the SummitStack feature.
- Stacking mode is active on the node.
- All nodes in the active topology have master-capability turned off.
- There is no master node in the active topology.
If the above conditions are met, five minutes after starting the node and every five minutes after that, the following message displays on the console:
```
Warning: the stack has no Master node and all active nodes are operating 
with master-capability turned off. If you wish to reconfigure, you may log 
in using the failsafe account. Alternatively, you may use the special login
REBOOT AS MASTER-CAPABLE with no password to force a reboot of a node with 
master-capability temporarily turned on.
```
Using the special login ID does not alter the master-capability configuration permanently. If you restart a node that has been restarted with the special login ID, that node restarts using its configured master-capability, unless you again use the special login ID to restart.

When a node has been rebooted using the special login ID, it becomes a master node. While the node is a master, the special login ID is not recognized, even though the entire stack is still configured as not master-capable. To get the special login ID to be recognized, the node must be rebooted again.
If a node was intentionally separated from the stack without first being unconfigured, its security configuration might be unusable. In this case, perform the following steps:
1. Connect to the node's console port.
2. Reboot the node using the special REBOOT AS MASTER-CAPABLE login ID described in step 1.
3. During the reboot, enter the bootrom program by waiting until you see the message Starting Default Bootloader ... and then pressing and holding the space bar until the bootrom prompt displays.
4. Force the switch to boot up with a default configuration by entering the following commands at the bootrom prompt:
```
config none
boot
```
The switch boots up in stacking mode operating as a master-capable switch. You can then log in using the default admin account with no password.

Published March 2020prev | next

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