Case study: straightforward tech question, genAI is repeatedly, confidently wrong

I recently discovered that when I migrated one of my CentOS servers from using if-up/down scripts to configure its network interfaces, to using NetworkManager (a migration which was forced on me by CentOS), a critical aspect of my network configuration was lost: the server stopped using the correct source address for outbound IPv6 connections. My server is assigned a dedicated /64 block by the VM hosting company, and outbound connections are supposed to come from that block. Prior to the switch to NetworkManager, they were; after the switch, they were not. I spent several hours web-searching for and reading online documentation and discussions unsuccessfully trying to figure out how to tell NetworkManager how to configure the default source address for outbound IPv6 connections. I finally decided to resort to Microsoft Copilot Chat to see if it could guide me in the right direction. On the plus side, by the end of my chat with Copilot, I had found an adequate solution to the problem.…