Local hostname changes every few seconds when NOT connected to a network

bonjourdnsNetwork

When ever I wake my laptop, but before I am connected to a network, I receive messages similar to the following:

This computer's local hostname
"sojourner-896.local" is already in use on
this network. The name has been changed
to "sojourner-972.local"

If I do not connect to a network and I do not click the "OK" button, the hostnames keep incrementing. If I connect to a network (either wired or wireless), the names stop incrementing.

I reset the hostname in the "Sharing" preference panel when the hostnames get in the 5,000 – 6,000 range (every 2-3 days).

Any idea what would be causing this?

Best Answer

I looked in the logs via the console app and found the following logs are generated every time I am disconnected from a network:

8/29/14 10:07:59.087 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7647.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:07:59.087 PM mDNSResponder[414]: mDNSCoreReceiveResponse: ProbeCount 2; will deregister    4 sojourner-7647.local. Addr 127.0.0.1
8/29/14 10:07:59.087 PM mDNSResponder[414]: Local Hostname sojourner-7647.local already in use; will try sojourner-7743.local instead
8/29/14 10:08:00.923 PM mDNSResponder[414]: Name Conflict: Updated Local Hostname from "sojourner-7647.local" to "sojourner-7743.local"
8/29/14 10:08:00.944 PM configd[26]: setting hostname to "sojourner-7743.local"
8/29/14 10:08:02.145 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7743.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:02.145 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:    4 sojourner-7743.local. Addr 127.0.0.1
8/29/14 10:08:02.145 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7743.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:02.146 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:   16 sojourner-7743.local. AAAA FE80:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:02.456 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7743.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:02.457 PM mDNSResponder[414]: mDNSCoreReceiveResponse: ProbeCount 2; will deregister    4 sojourner-7743.local. Addr 127.0.0.1
8/29/14 10:08:02.457 PM mDNSResponder[414]: Local Hostname sojourner-7743.local already in use; will try sojourner-7765.local instead
8/29/14 10:08:04.365 PM mDNSResponder[414]: Name Conflict: Updated Local Hostname from "sojourner-7743.local" to "sojourner-7765.local"
8/29/14 10:08:04.375 PM configd[26]: setting hostname to "sojourner-7765.local"
8/29/14 10:08:04.633 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   22 1.0.0.127.in-addr.arpa. PTR sojourner-7743.local.
8/29/14 10:08:04.633 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Unexpected conflict discarding   22 1.0.0.127.in-addr.arpa. PTR sojourner-7765.local.
8/29/14 10:08:04.734 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   22 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.e.f.ip6.arpa. PTR sojourner-7743.local.
8/29/14 10:08:04.734 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Unexpected conflict discarding   22 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.E.F.ip6.arpa. PTR sojourner-7765.local.
8/29/14 10:08:05.839 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7765.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:05.840 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:    4 sojourner-7765.local. Addr 127.0.0.1
8/29/14 10:08:05.840 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7765.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:05.840 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:   16 sojourner-7765.local. AAAA FE80:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:06.141 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7765.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:06.141 PM mDNSResponder[414]: mDNSCoreReceiveResponse: ProbeCount 2; will deregister    4 sojourner-7765.local. Addr 127.0.0.1
8/29/14 10:08:06.141 PM mDNSResponder[414]: Local Hostname sojourner-7765.local already in use; will try sojourner-7802.local instead
8/29/14 10:08:08.006 PM mDNSResponder[414]: Name Conflict: Updated Local Hostname from "sojourner-7765.local" to "sojourner-7802.local"
8/29/14 10:08:08.016 PM configd[26]: setting hostname to "sojourner-7802.local"
8/29/14 10:08:08.268 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   22 1.0.0.127.in-addr.arpa. PTR sojourner-7765.local.
8/29/14 10:08:08.268 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Unexpected conflict discarding   22 1.0.0.127.in-addr.arpa. PTR sojourner-7802.local.
8/29/14 10:08:08.357 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   22 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.e.f.ip6.arpa. PTR sojourner-7765.local.
8/29/14 10:08:08.357 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Unexpected conflict discarding   22 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.E.F.ip6.arpa. PTR sojourner-7802.local.
8/29/14 10:08:09.465 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7802.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:09.465 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:    4 sojourner-7802.local. Addr 127.0.0.1
8/29/14 10:08:09.465 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7802.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:09.465 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:   16 sojourner-7802.local. AAAA FE80:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:09.733 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7802.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:09.733 PM mDNSResponder[414]: mDNSCoreReceiveResponse: ProbeCount 2; will deregister    4 sojourner-7802.local. Addr 127.0.0.1
8/29/14 10:08:09.733 PM mDNSResponder[414]: Local Hostname sojourner-7802.local already in use; will try sojourner-7837.local instead
8/29/14 10:08:11.578 PM mDNSResponder[414]: Name Conflict: Updated Local Hostname from "sojourner-7802.local" to "sojourner-7837.local"
8/29/14 10:08:11.588 PM configd[26]: setting hostname to "sojourner-7837.local"
8/29/14 10:08:11.815 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   22 1.0.0.127.in-addr.arpa. PTR sojourner-7802.local.
8/29/14 10:08:11.815 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Unexpected conflict discarding   22 1.0.0.127.in-addr.arpa. PTR sojourner-7837.local.
8/29/14 10:08:11.915 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   22 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.e.f.ip6.arpa. PTR sojourner-7802.local.
8/29/14 10:08:11.915 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Unexpected conflict discarding   22 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.E.F.ip6.arpa. PTR sojourner-7837.local.
8/29/14 10:08:12.786 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7837.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:12.786 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:    4 sojourner-7837.local. Addr 127.0.0.1
8/29/14 10:08:12.786 PM mDNSResponder[414]: Excessive name conflicts (17) for sojourner-7837.local. (Addr); rate limiting in effect
8/29/14 10:08:12.786 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Received from 127.0.0.1:5353   16 sojourner-7837.local. AAAA 0000:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:12.786 PM mDNSResponder[414]: mDNSCoreReceiveResponse: Resetting to Probing:   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:0000:0000:0000:0001
8/29/14 10:08:12.786 PM mDNSResponder[414]: Excessive name conflicts (18) for sojourner-7837.local. (AAAA); rate limiting in effect
8/29/14 10:08:14.193 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:14.194 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:14.497 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:14.497 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:14.914 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:14.914 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:14.914 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:14.914 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:14.915 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:14.915 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:14.915 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:14.915 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:15.504 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.504 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:15.504 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.504 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:15.504 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.505 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:15.505 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.505 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:15.911 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:16.212 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:16.213 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:16.213 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:16.213 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:16.213 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:16.213 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 8323688E   16 sojourner-7837.local. AAAA FE80:0000:0000:0000:2CBE:08FF:FE8F:BCBA
8/29/14 10:08:16.213 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Pkt Record:        00004008    4 sojourner-7837.local. NSEC Addr
8/29/14 10:08:16.213 PM mDNSResponder[414]: ResolveSimultaneousProbe: 000000000000000A Our Record 3 lost: 002B5510    4 sojourner-7837.local. Addr 172.20.10.2
8/29/14 10:08:19.916 PM digest-service[701]: digest-request: init return domain: SOJOURNER-7647 server: SOJOURNER-7837 indomain was: <NULL>
8/29/14 10:08:19.937 PM digest-service[701]: digest-request: init return domain: SOJOURNER-7837 server: SOJOURNER-7837 indomain was: <NULL>

I re-enabled the network around second 10:08:14.

The actual process which was changing the hostname is configd. The man page for configd states that

The configd daemon is responsible for many configuration aspects of the
local system. configd maintains data reflecting the desired and current
state of the system, provides notifications to applications when this data
changes, and hosts a number of configuration agents in the form of loadable
bundles.

and

At the present time, the majority of the configuration agents (or bundles)
hosted by configd are used to establish and maintain the network
configuration.

The man pages lists the following related files:

 /Library/Preferences/SystemConfiguration/preferences.plist
 /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist
 /Library/Preferences/SystemConfiguration/VirtualNetworkInterfaces.plist

The file preferences.plist appears to have the network preferences as specified by the Network preference panel in System Preference. I made a backup, deleted it, killed configd, and performed a low level reboot:

cd /Library/Preferences/SystemConfiguration/
cp preferences.plist ~/Desktop/preferences.plist
sudo rm -f preferences.plist
sudo killall configd
sudo killall configd
sudo reboot

After the system rebooted, the system no longer changed the host name every few seconds when NOT connected to a network.

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