Cisco Novice Causes Chaos with One Wrong Connection

A young network engineer, self-proclaimed as 'The Cisco expert', was sent to a customer site despite having only three months of experience.

The engineer, who wishes to remain anonymous, arrived at the site and completed the rack and stack, basic default configuration, and VLANs discussed over coffee with the customer's IT team.

However, upon connecting the new switch, over 4,000 AS/400 sessions dropped, causing a significant disruption to the customer's operations.

The engineer admitted that there was a clear cause-and-effect relation between the time he connected the switch and the sessions dropping. He also acknowledged that the only way to restore those sessions was for the IT team to manually kill them one by one.