NAT ⁽¹⁾

After a life in IT you'd think I would be better at this stuff. Two things caught me out this week, both around the web server that runs this blog among other things. The first knocked it offline and I was unaware. The server is a dimimutive Lenovo ThinkCentre M92p and has 4 USB ports but none work which was annoying as I wanted to upgrade Lubuntu but really wanted a decent backup to an external device first. I had another of these systems with working USB ports so I swapped the hard disk between the two - the specs are essentially the same. All went well, apparently. I attached a USB SDD to use as a backup for the pending operating system upgrade. Then I noticed no incoming email plus I tried to access the blog from an external IP and it failed. Odd. No issues with accessing from the house LAN. Then I remembered having an issue with the PlusNet router but could not remember what so I logged into that to see if my memory would return. And it did. The PlusNet router helpfully follows MAC addresses rather than IP addresses so when I swapped the HDD…