Local hostname has been changed? Why?

Discussion in 'Mac OS X Server, Xserve, and Networking' started by bdougla63, Mar 26, 2010.

  1. bdougla63 macrumors newbie

    Mar 25, 2010
    Hi everyone

    Got this weird message on my G5 and I have no other computers networked to it.
    "This Computer's local hostname "****computer.local" is already in use on this network. The name has been changed to "****-2.local" automatically

    To change the local hostname open System Pref. and click sharing. Then click edit and type the name in the local hostname field."

    Why would this happen?
  2. mikelangelo11 macrumors newbie

    Mar 25, 2010
    when another computer is on the network. Are you running a wireless network, or is the computer plugged directly into the the cable modem
  3. Pinkerton macrumors newbie

    Jun 5, 2009
    San Jose, CA
    I've had the same or a similar issue. My computer was constantly renaming itself with a (2) every time it booted, after a system lockup. I tracked the issue down to CD/DVD sharing... when turned off the problem went away.

    When CD/DVD sharing was on, I could not change the name back to the original version, it would get rejected and immediately set back to the version with "(2)", displaying the message:

    The name of your computer "Name" is already in use on this network. The name has been changed to "Name (2)" automatically.

    With CD/DVD sharing turned off, I could name my computer whatever I liked, even back to the original name. Turning DVD/CD sharing back on again would instantly rename my Mac. It's very persistent bug!

    Fortunately I found a fix. I was able to get rid of the problem by toggling Bonjour, as described here:


    To turn Bonjour off:

    sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

    To turn it back on:

    sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

    Toggling Bonjour (mDNSResponder) forced a reset of something on my system somewhere, and now I no longer see the issue on reboot, even with CD/DVD sharing turned on. I can turn sharing on and off at will, and my computer is never renamed. Success!

    I don't think this problem has to do with CD/DVD sharing specifically... I think it's a bug in Bonjour. I've seen threads where people have complained about this issue because of printer sharing, or remote management! My guess is that a crash can cause a mDNSResponder config corruption, tricking Bonjour to share devices or services using the same name as your computer, forcing the name conflict.

    In any case, I hope this fix works for you too. I know I'm a lot happier now that there isn't a lingering issue on my box!
  4. jerry333 macrumors regular


    Nov 4, 2005
    This seems to be a problem with Snow Leopard Server. It can happen anytime you (or the system) changes or refreshes network settings, adds an alias, etc. To check:

    scutil --get ComputerName
    scutil --get HostName
    scutil --dns

    If the hostname is wrong use:
    scutil --set <ComputerName|HostName> <correct value>

    Of course, you have to be root to do this.
  5. cottcpa macrumors newbie

    Mar 5, 2011
    follow up on changes to local host name

    Hi everybody, I'm experiencing a similar problem to that which was discussed here a few months ago. It all started when I changed my airport settings to make the network hidden and changed the security from WPA/WPA2 to WPA2. The same night I received the message about a change to the local host name (changed to "NAME-2"). I immediately changed the settings back to WPA/WPA2.

    My firewall is on; stealth mode is on. I use little snitch as well. All sharing is turned off.

    Today I had another incident of a change to my local hostname (now NAME-3) As far as I know, my IMAC is the only computer connected to the hidden network.

    I ran the get-host-name function in terminal and it says that no hostname has been set.

    I also noticed today that when I would wake my IMAC from sleep, there would be a brief moment where the screensaver appeared as a picture I've never seen before. Immediately after the username/password box opens followed by my normal screen saver.

    I also noted twice today that my external hard drive ('time machine') was suddenly dragged quickly across the screen as if I dragged it myself; then disappeared from the windowpane as if I unplugged it. I have a few devices including this HD running through a single hub, but this hard drive was the only device turned on.

    Please let me know if anyone can help me understand what's going on. I'm pretty unlearned when it comes to these things so will appreciate the help. All this in one day concerns me.
  6. paisleypaper, May 18, 2011
    Last edited: May 18, 2011

    paisleypaper macrumors newbie

    May 18, 2011
    Same question

    This is the same thing that I have. The solutions suggested mention more than one computer or device to rename. That does not apply for me. There is just the one computer. Does that mean that some other unknown computer is getting in?? This just happened yesterday. Have not changed anything. Thanks for any assistance. I do not understand what this terminology means, and what I should do.
  7. bill howell macrumors newbie

    May 31, 2010
    Saginaw, Michigasn
    Bill in Michigan

    I have an iMac running 10.7.4 server that is connected to a lAN plus airport. I access printers and a server raid using the lag and sync an iPad, iPod and IPhone using airport. When airport is on I get the message:Hostname is already in use on network. Neme has been changed. All hostnames are unique on the WIFI and lan. The airport is set up as a bridge. When I turn airport off the message does not appear. When I turn Airport on it appears regularly.
    I appears that the LAN router and Airport both assign ip numbers to the same machine.
    An ideas on how to remedy this problem?

Share This Page