mac name with number changing??

Same here, it's awfully annoying and happening on multiple devices and today I had to sign into iMessage with my usual login and had to verify an email sent by apple and once I did that my iPhone starting saying new device Your MacBook (2) added. This is getting out of hand where the computer name changing itself to multiple name with brackets (2), (3) etc as it is now affecting iCloud login and device names on multiple devices and really urgently needs addressed.

Hello,

I would like to confirm I also have the same problem of computers duplicates which appears in the Shared list, with "Name of computer (2)", (3), (4) and so on.

1. I just notice that the problem occurs to "bonjour computers" only, not the stations or servers with AFP disk sharing.
2. The problem happen to my laptop (Macbook pro), with Yosemite. When I have tried to rename the computer using the "Sharing", the problem temporarily stopped, until the problem happened again, with the new name.

I did not have as many issues with iCloud, yet.

Seems the post answer the question. The solution worked for me: Network: single computer repeatedly listed in sidebar

I'm having the same problem with my mid-2011 27" iMac on a wireless network with a 2TB Time Capsule router (no ethernet cable connected to any machine). My 2013 MacBook Air on the same wireless network has no problem--its name hasn't changed once. The iMac, on the other hand, consistently changes its name, each time adding a number (2) (3) and so on. If I share the iMac, each of the instances shows up in the MBA's Finder sidebar under shared. Each computer is running Yosemite. Here's what I've tried:

1. Changing the iMac's name under Sharing preferences. For instance, changing the name of the computer from "Name's iMac" to "Office iMac." Didn't work.
2. Resetting the Time Capsule to factory settings. Seems to work only temporarily, but the problem returns.
3. Nuclear option. Reset the Time Capsule to factory settings (again) and performed a clean install of Yosemite on both the iMac and MBA. Thought I had the problem solved with this rather drastic approach, but the problem returned on the iMac today. MBA is still fine. Never turned on sharing after reinstalling Yosemite (thought the problem might have something to do with this), but this doesn't seem to have any effect, either. Problem persists.

I've spoken with Apple Support and they were just as baffled. They recorded all of my settings and network information, sending it the engineers. I'm still awaiting a response (it's been three days--I was told it may take up to four). Really annoying problem. I can't be certain that Yosemite is causing the issue, but I never had this happen in Mavericks with the same network setup.

Per the link above, I've enabled BTMM via the AirPort Utility by entering my Apple ID and password (note: I haven't checked BTMM under iCloud settings on either my iMac or MBA), so I'll see if this works. I'm not hopeful, as I had BTMM enabled when the issue first appeared. I'm going to give it a day or two to see if the iMac's name changes again.

Thomas, I have the same issue. Thought for a while it was the combination of Printopia and Yosemite, but it certainly is not. Then thoughts around how iTunes is sharing across the network. But changing all of the settings seem to do nothing. I've tried turning off the "Wake for Network Access" and "Power Nap" features with no luck.

Please Apple find a solution.

We are also experiencing the problem. A mid-2012 macbook pro is appearing on the network multiple times, with the name the same except appending (#) where # keeps incrementing upward (i.e. (1), (2), etc). We are not having the problem with 2 mac minis, a macbook air and an older macbookpro. All machines are running 10.10.1. Have tried a few of the solutions posted here and in another thread. No luck yet. Sent some "feedback" to apple.