Never install a tool unless you’re certain what it will do. I just installed ez-ipupdate, and set it to look on eth0. I was trying to set it up so I wouldn’t have to call my Mom (when at Dad’s) or check ipchicken every time my IP changed, and just have my server update the DNS automatically. Unfortunately, the tool obediently checked the IP on eth0, and found it to be 192.168.1.100, the LAN IP of the server, which was different than what was listed. It changed it immediately. I had a hunch right after I hit OK that it might do that. Sure enough, the records flashed from the correct IP to that of 192.168.1.100, the LAN IP. I tried checking some DNS lookups, hoping that some delay in DNS updates would give me correct IP. It didn’t, and I turned to other sources. Mom didn’t answer the phone, so I tried checking my bash history. Luckily, I still had an ssh command logged with the numeric IP from when I was checking the IP earlier. I manually changed it back, and hastily uninstalled ez-ipupdate. Whew.