For $reasons it happened a few times that I needed to renumber a VLAN in a campus or DC network. The first time the customer had to remove all the clients in VLAN 1 to comply with the network design standards of the company after a merge with a large international group. In other cases, the customers assigned the same …

Network changes tool to prevent disasters. Network changes Every time I manage a change to a customer network I have a chance to taste the many shades of possible IT Operations maturity levels. I collected some best practices over the years about how to reduce risk and speed-up the change and testing process. I'll …

This story starts with a phone call at night. If you worked in IT long enough you know what it means. Customer's HQ network is down and since the day before I've replaced a pair of data center switches in a remote site I'm somehow involved based on the well-known principle last one who made changes is responsible. I …