The ExtremeSwitching switch displays only the "(pending-AAA) login" prompt

It is possible that the switch has not yet been fully initialized in the SummitStack. Wait for the Authentication Service (AAA) on the master node is now available for login. message to appear and then log in normally.

It is also possible that the stack has no master-capable node. In this case, AAA authentication will not be possible. This can occur when a stack has been deliberately dismantled and stacking was not unconfigured beforehand.

In either case, you may log in to the node using the failsafe account. If you have forgotten this account, and the stack has no master-capable node or has been dismantled, see Rescuing a Stack that has No Primary-Capable Node.

The "(Pending-AAA) login:" prompt on other switches.

This login prompt is discussed in Logging in to the Switch.