Home Forums Networks & Cross-Platform Networking Local hostname change

Woke up my computer this morning for the usual post breakfast mail and web check to find an alert on the desktop which reads:

This computer’s local hostname ”Andy-Reids-Computer-2-local” is already in use on this network. The name has been changed to ”Andy-Reids-Computer-3-local”.

What? Why? I have updated several apps in the past few days in preparation for the leap to Mojave (eg Diskwarrior, Carbon Copy Cloner, ClamXav) but haven’t, as far as I know, done anything to initiate a change to the local hostname. I did connect and format (HFS+) a new SSD drive for post Mojave clone purposes but it doesn’t seem likely that this is the culprit.

I haven’t changed the hostname back in the Sharing Preference yet and maybe I shouldn't. It may be a non-issue but something, as well as standard security paranoia, tells me it’s a bit odd. Does anyone have any ideas?

Andy
Late 2013 iMac, 10.13.6

That has happened to me on several occasions over the years. I can't prove this, but my theory has always been that for one reason or another key computer had attempted to logon to the LAN while the router thought there was still a connection to Andy-Reids-Computer-1-local so a new connection to Andy-Reids-Computer-2-local was created. Rebooting the router would get rid of Andy-Reids-Computer-local, and Andy-Reids-Computer-1-local connections in the router, but you would still been known as Andy-Reids-Computer-2-local. ie. no big deal. But that is just my explanation. of the phenominum.

Thanks mate. After I posted I googled the alert (should have done this first!) and, as is often the case, was presented with a lot of confusing and/or frightening information pointing the finger variously at OS bugs, router issues, Bonjour failures, and neighbourhood WiFi invasions. I ran Wireless Diagnostics which indicated a LAN conectivity failure (--> try restarting your router) and poor wireless environment (which I can't do anything about). As suggested by one of the google results I then ran something called iStumbler which I suspected might not help because its report would likely challenge my computerlectual abilities. This proved to be the case and I continue to stumble around.

At this point I might limit my response to the alert by just rebooting the router!

Any details on what makes the wireless environment poor? There are lots of possibilities, and while you may not be able to do anything about them, you may be able to take steps to mitigate the risk.