Terry Slattery, CCIE #1026
We recently had a near-disaster occur at a customer. A 6500 10/100 ethernet blade had died and was replaced. When the replacement blade was installed, the configuration for its interfaces disappeared from the configuration! The techs couldn't figure out what happened. They saved the current config as part of their normal operations, but now the old configs were missing from both the running and saved configurations. With the interface configs now missing, they called for assistance from the network engineering group.
If you want a good thought exercise, stop reading now, try to figure out what happened, then read the solution below.