My iMac's computer name keeps changing automatically after Yosemite upgrade

I changed the Wake-On LAN settings when you recommended the change back on the 31st. The name changed again so I again ran the permissions repair piece. Since I ran the permissions repair the name has not changed. It has been almost a week now.

Thanks!

Thank you very much, farquaad - this has seemingly resolved the problem for me (which was quite annoying!).

These boards are terribly good for resolving such issues, and I don't always take the time and trouble to write every time and say thank you - which I should!

Thank you! 🙂

Thanx, this worked for me!!!

Thanks, I changed mine In Preferences > Energy Saver > deselect Wake for network access, as you suggested. It's not changed back, it's been 5 days so far!

Tried both the solution that farquaad and markisttoll suggested, and seems to be working for now. This becomes a REAL issue if you are

1) using a networked Time Capsule - when your computer just randomly gets renamed, Time Capsule does not recognize your machine on the network and therefore does not run your backups. Not good.

and

2) running anything locally for web dev - in my case MAMP Pro and CodeKit. Codekit resolves to your computername.local when running anything dynamic, so renaming your local box totally jacks your dev environment. Meanwhile MAMP Pro sees that you have your app registered and tied to computername, but you are now running computername (2) - so it figures the serial number is already in use, and quits. Only solution there is to find your MAMP Pro registration file (which is in username ▸ Library ▸ Application Support ▸ appsolute ▸ MAMP PRO ▸ Registration 3.0 file) , delete it, rename your computer, restart, launch MAMP Pro, then re-enter your registration info. Serious headaches there.

I have tried the following....

• Repair permissions
• Set up a DHCP reservation for each connected Mac.
• Turn off Back to my Mac
• Turn off File and Screen sharing (unchecked everything in Sharing)
• Turn off Wake on LAN

I am still seeing this issue. I have had the Mac change it's name as I am using the computer so it's not a sleep/wake issue in my case.

I changed out the router to a brand new Airport Extreme 802.11AC and I am still seeing this issue.

Thoughts?

This worked perfectly, thanks!

It's not a router issue, that's for certain. Routers can't push a name change back to your computer. It's something in the system itself, either dynamically creating a new user or dynamically changing the name of an existing user. It's a PITA for sure. Best thing to do is what's suggested at the very bottom of this page http://ispire.me/fix-yosemite-rtc-alarm-wakeup-issue/ regarding the user name changing, which is to run this as sudo from terminal:

sudo /usr/libexec/PlistBuddy-c "Add :ProgramArguments: string --no-namechange"/System/Library/LaunchDaemons/com.apple.discoveryd.plist

...which is working for me.

Thx for this, I may try it tonight and see how it goes. 🙂

Turning off Back to my Mac seems to have resolved my issue as well, thanks!

I hope the people at Apple find a way to correct this soon.

Thank you so much. This worked perfectly for my MacBook Pro and iMac. You just saved me hours of frustration:)

farquaadOct 29, 2014 11:35 AM Re: My iMac's computer name keeps changing automatically after Yosemite upgrade
Re: My iMac's computer name keeps changing automatically after Yosemite upgradein response to theshadow82

Have had the same issue with an iMac and MacBook Pro, both with Yosemite (MacBook upgraded from the Yosemite public beta). Both previously had Mavericks, and at one time or another would have had both Ethernet cable and Wifi on. This issue has only occurred since the upgrade to Yosemite. I do not use iCloud, so I believe that may be irrelevant and merely coincidental.

The solution provided by an Apple Care rep seems to have resolved the issue. Has stuck now on both machines for the last few hours. Time will tell for certain, but here's what we did:

- in System Preferences > Sharing, remove the (2) [or whatever is extra; mine was iMac (2), so I removed the (2)

- exit Preferences

- shutdown

- restart machine in Recovery mode (machine off, press and hold Command + R, power on, when Apple logo appears release keys)

- may take a few minutes to boot (depends on machine generation/speed, RAM and such)

- open Disk Utility

- select the OS disk (mine was Macintosh HD; selected the 'indented' item)

- run Verify Disk Permissions

- when finished run Repair Disk Permissions

- restart

On the MacBook I tried turning on Wifi and so far so good.

Banish the deux!

Spoken too soon, I've come home to find my machine was already at (3) 😠

I have had a similar situation and think I may have prevented it from happening with my computer, even if I have not addressed the root cause. My Macbook Pro added (2) to the name immediately after turning on, but did not continue to add numbers as it goes. I tried farquhaad's suggestion, but it did not seem to help. Then, I found that my iPod touch, on the same wireless network had the same name as my Macbook. I changed the iPod touch name. Now my Macbook no longer adds the (2) to its name. So in my case, it seems my computer renames itself if there are any devices on the same wireless network with the same name. I don't know if that helps your situation or not, but thought I would share just in case.

First, I appreciate those who have returned to the discussion to post results, as well as expressed acknowledgement and thanks to me and others for the solutions we have offered. Glad to help and it worked (for most?!).

Second, to update my experience, since my original post and performing the permissions repair and removing the network access wake option, I have not had any issue with any of my Macs renaming themselves. I have never used iCloud or Back to My Mac.

Incidentally, this is not a router issue, as routers do not name a device; it would simply report that a device already has a particular name, and there cannot be duplicate names on the network, in which case the OS would have to respond/take an action. I use an ASUS router in one location and an Airport Time Capsule in another.

Some of you are reporting strange renaming behaviours indeed, and who knows the myriad variables in play with each situation. Hopefully this annoying issue gets resolved in the next OS update, which was seeded to machines with the beta Yosemite just a few days ago, and meanwhile the solutions posted here do the trick.

Cheers.

I too had/have this issue.

One 2011 10.10 iMac has the issue, a 2008 10.10 macbook does not.

I have an older 2TB Time Capsule and a current Apple TV.

One additional thing I've noticed is that on the affected iMac, when the (2) name is being displayed, it is also displayed in the "shared" category of Finder window sidebars. I believe this is not normal behavior, to see your own computer in the shared list. When I fix the name, removing the (2) it is no longer displayed in "shared. I wonder if others are seeing this too?

I've been able to avoid the problem for 24 hours under the following conditions:

Apple TV set to never sleep

Time Capsule router has timed access via MAC address disabled, back to my mac credentials are in place and active, there are no DHCP assignments

On the iMac, I have disabled "wake for network access" (I think this was the issue) I repaired disc permissions, all network services are disabled except for Wifi. Back to my mac is on, AFP file sharing and screen sharing are enabled.

So if this lasts a few more days I will slowly return settings back to normal, saving wake for network access for last and see what happens.