Computer Name With Number

I'm having the same issue with my iMac (early 2008) and MacBook Pro (2010). It's very weird, both machines insist on appending numbers in parentheses to the end of the Computer name: in the Sharing preference panel. However the name given beneath that in the message "Computers on your local network can access your computer at: <computer-name>.local" does not include the number, just the normal hostname.local. Also, using hostname command in terminal returns the regular <computer-name>.local without a number.

If I remove the (n) at the end of the Computer name: field it only lasts a few seconds before changing back to a number (though the number is not always the same as before, sometimes it goes to (2) or (3) rather than the (4) it was originally.

If I open a Finder window with the sidebar showing I see under Devices an entry for "<computer-name> (4)" and under Shared it shows:

<computer-name>

<computer-name> (2)

<computer-name> (3)

I have screen and file sharing enabled, I tried switching them off and on again, I've tried rebooting, nothing seems to stop it appending the number and I can't get rid of the <computer-name> (2) and <computer-name> (3) entries under Shared either.

Most likely an issue with your network (router). Some of them don't like macs. There where issues with some models last year with Mavericks too.

Additional: Although I did have the problem with both machines post-Yosemite upgrade yesterday now it seems that only the iMac is still affected. I just powered on the MBP and now it's not having the issue anymore. I know I did remove the (n) entry in Computer name: prior to shutting it down yesterday, apparently it didn't switch back to using it like the iMac keeps doing, I have no idea why...

I'm using an Airport Extreme router so I doubt that's the problem... If I launch Airport Utility and check what's logged in it shows the "<computer-name> (4)" entry for the iMac and the normal hostname with no number for the MBP.

Ahha! Seduc's suggestion made me think of rebooting my Airport basestation; while that was happening I removed the number in the Computer name field of the iMac and this time it stayed gone. When the basestation came online again it seems to have fixed the problem! No more numbers, no more additional entries under Shared.

This sounds similar to a discussion I saw earlier today:

http://www.reddit.com/r/osx/comments/2hxhp9/yosemite_computer_name_changing_for_ some_reason/

They seemed to be able to resolve the problem. Worth a shot I guess.

A couple of days after fixing this problem by rebooting my AE I noticed that the computer name on my iMac had once again changed (the MBP's name was fine), this time to <computer-name> (2). No idea why, I did nothing unusual around that time that I'm aware of.

This time however when I changed the name back to <computer-name> in Sharing preference panel it stayed changed and I didn't need to reboot AE or anything. So far it's continuing to behave itself, but I'm keeping an eye on it in case the problem recurs.

Same thing here. I rebooted my Airport Express last night, changed my computer name and it stuck until this morning.

I did find a pattern though. It stuck until this morning but then I started my VPN connection for work. It seems to have changed after that.

This is completely new in Yosemite (10.10), I've never had this problem before. My screen saver is my machine name, so I definitely would have noticed if I had this problem before. This machine has been through the last 3 major Mac OS X versions also.

It doesn't matter what I do, this "Computer Name" issue just keeps coming back... Reboot AE at home or Time Capsule at work - doesn't help... This is a BIG DEAL because it has caused some of my Time Machine Backups to start over (network backups) which takes hours and hours. Apple has had this problem in the past at major OS X updates then fixed it in later updates... Same with wifi issues... I don't get it...

I just tried this and it seems to be holding - with airport extreme & time capsule:

• login using airport utility

• under the wireless tab - DISABLE GUEST NETWORK - this seems to stop the ghost mac

• in the wireless options tab - DISABLE 5GHZ NETWORK - this seems to stop the ghost mac

- UPDATE YOUR AIRPORT OR TIME CAPSULE - RESTART YOUR ENTIRE NETWORK

- RESTART ALL DEVICES

• on Mac's / Syst Prefs / iCloud / uncheck Back to My Mac / re-check Back to My Mac

I have never gotten better speed, reliability or distance with 5GHZ anyway...

SpeedTest.net says 90MB download / 6MB up with 5-GHZ turned on or off. Tested on my Mac, MBP, MBA and iPhone

Working so far, we will see...

Sorry @Macsterguy, seems like it's just a coincidence that it's working for you. I don't have the guest network enabled or 5ghz enabled and I have this problem from the day I installed Yosemite. 😟

For all, File a bug report with Apple.The more people file BRs, the sooner Apple will fix this known bug which occurred during beta testing.

27" i7 iMac (Mid 2011) refurb, OS X Yo (10.10), Mavs, ML & SL, G4 450 MP w/10.5 & 9.2.2

Here is the solution:

Go to Macintosh HD > Library > Preferences > SystemConfiguration

and delete the following files:

com.apple.airport.preferences.plist

NetworkInterfaces.plist

preferences.plist

Empty trash, then reooot. The deleted files will be recreated and you should be good to go.