How can I stop Mac OS X overriding my hostname when I receive a DHCP request on Snow Leopard?

Question

Whenever I go on a network where the DHCP server assigns hostnames then it overrides the settings I've set for my hostname on my Mac in the "Sharing" section of System Preferences.

How do I stop this behaviour from occurring and always have the same hostname set under Snow Leopard?

score 143 · Answer 1 · edited Dec 14 '15 at 18:10

143

Set it in the Terminal with:

sudo scutil --set HostName <putinyourhostname_or_fqdn_here>

like in:

sudo scutil --set HostName server1.mynetwork.com

edited Dec 14 '15 at 18:10

Giacomo1968

55,001

answered Oct 02 '09 at 16:50

Wolf

2,553

3

Verified that this also works on Leopard (Mac OS X 10.5.8). – Vebjorn Ljosa Jan 30 '10 at 21:33
3

Didn't need sudo in Snow Leopard (Mac OS X 10.6.2) – Garth Kidd Apr 14 '10 at 06:15
works great, hostname now shows up on the status page for my dd-wrt flashed router. – Robert S Ciaccio Aug 25 '10 at 06:14
2

Works in Lion (10.7.2) too – etarion Jan 20 '12 at 18:29
in 10.7.4 I get a > prompt after this commmand – CharlesB Jun 28 '12 at 13:25
Anyone know what the default is or how to reset the default? – wfaulk Aug 10 '12 at 17:50
2

The default, as it turns out is unset. The command to unset is scutil --set Hostname "". – wfaulk Aug 10 '12 at 18:07
5

Verified that this also works on Mountain Lion (10.8.2) – DerMike Jan 28 '13 at 13:00
Didn't necessarily need sudo under Mountain Lion (10.8.3), but I did get a GUI prompt for my password. – Blacklight Shining May 08 '13 at 15:59
12

Works on 10.9.... – Dan Pritts Oct 29 '13 at 02:28
Working on 10.10. – Justin Megawarne Oct 26 '14 at 21:27
Doesn't really work on 10.10. Now my Mac answers to both hostnames. System settings still shows the one with the extra number, scutil in terminal shows the hostname without extra number. – Arne Nov 03 '14 at 20:17
Works for me on 10.10. – Brovaccie Apr 23 '15 at 14:04
2

Working on 10.11. – Nupraptor Oct 19 '15 at 16:49
@JakeGould , @Wolf : A better method to set all hostname types is to use this one-liner: export MY_HOSTNAME=foobar ; for n in LocalHostName ComputerName HostName ; do sudo scutil --set $n $MY_HOSTNAME; done – TrinitronX Dec 30 '16 at 22:04
1

Verified working on 12.0.1 Monterey – Brendan Baldwin Nov 05 '21 at 00:38

score 29 · Accepted Answer · edited Sep 27 '12 at 18:24

29

In short: there is an auto-magic behavior that Mac OS uses, by default.

You can turn it off in /etc/hostconfig.

http://excitedcuriosity.wordpress.com/2007/08/24/mac-os-x-hostname-determination/

I like the answer by Jack M., but it doesn't work in many environments of the real-world DHCP environments, because you do not have a pre-existing relationship with the DHCP server. Only in a home setup or a corporate setup (where the IT people are helpful), can you get your desired hostname via DHCP.

In /etc/hostconfig add something like this:

HOSTNAME=your_hostname.your_domain.your_tld

If you want to set it at automatic again, either remove the line or set it to -AUTOMATIC-

edited Sep 27 '12 at 18:24

Wolph

625
5
16

answered Dec 21 '09 at 15:54

benc

1,322

2

This answer needs updating for 10.6. I'm looking at 10.5, and is already very different. – benc Dec 22 '09 at 08:42
6

For 10.6+, see @Wolf's answer – etarion Jan 20 '12 at 18:29

score 19 · Answer 3 · answered Oct 02 '09 at 14:50

19

Depending on how your DHCP is set up, you may be able to use the "DHCP client ID".

System Preferences.
Network
Select your network adapter on the left.
Select "Advanced" button at the bottom.
Set the "DHCP client ID" to your hostname.

If your DHCP server supports it, your hostname will be used for your machine.

answered Oct 02 '09 at 14:50

Jack M.

3,483

What if my DHCP server does support it? Every other OS I've used allows me to set my hostname myself, are you saying this is server dependant on OSX? – Mike McQuaid Oct 05 '09 at 09:17
This should make your hostname stick, unless your DHCP server is doing something really odd. I have my box called "shteef" in both Sharing (as you mentioned) and in the DHCP Client ID, and it works fine. – Jack M. Oct 05 '09 at 15:27
this did not work for me... scutil did however. And after using scutil, this field was filled. Strange. – Robert S Ciaccio Aug 24 '10 at 11:21
3

@JackM. DHCP client ID just means that the client ID is sent to the server during the DHCP negotiation; there is no requirement for a supplied client ID to make it to DNS. – Mattie Feb 18 '13 at 17:06

score 4 · Answer 4 · answered Mar 27 '14 at 04:30

4

Actually it's not related to DHCP. OS X checks the reverse DNS record of your IP and if there's one it's applied as your hostname.

answered Mar 27 '14 at 04:30

slash213

49

3

I realize this is an old answer, but do you know if there's any way to stop this behavior? – computergeek125 Nov 17 '16 at 06:25

score 1 · Answer 5 · answered Oct 02 '09 at 14:41

The Sharing panel doesn't necessarily set your hostname, it set's your bonjour host name, and is the default hostname. DHCP can and probably will override the default hostname. I don't know of anyway to override it, but maybe someone else does.

What I have done in a similiar situation is set up a DYNDNS account, and load the DYNDNS updater on your system. Then you can use the DYNDNS hostname from anywhere, including your local lan without worrying about what your dhcp hostname is...

How can I stop Mac OS X overriding my hostname when I receive a DHCP request on Snow Leopard?

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