Is it possible for a Mac using DHCP to have a static IP?

macuser1232

macrumors 6502a
Original poster
Jan 20, 2012
666
3
It's all in the title. I was just wondering this about my Macbook Pro. It's connected to my home's router.
 

chown33

Moderator
Staff member
Aug 9, 2009
8,550
4,604
inter-prandial
No. I don't want to have a static IP I just wanted to know if I may have had a static IP in the past and didn't know it.
Why do you ask? Are you seeing something that makes you consider the possibility? What?

It's possible it may have, but there's no sure way to tell what it was doing in the past.

There is an option in System Preferences > Network pane to use "DHCP with manual address", wherein you enter a specific (static) IP address. But someone would have had to choose this option (accidentally or intentionally), because the default is DHCP, i.e. DHCP with dynamically assigned address.
 
Nov 28, 2010
22,684
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located
No. I don't want to have a static IP I just wanted to know if I may have had a static IP in the past and didn't know it.
Normally DHCP provides a "static" IP, meaning upon reconnection to the router, it gets the same IP. Your home folder renaming adventure might have changed that, meaning you got a new IP, which will probably be the same upon reconnecting to your router.

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There is an option in System Preferences > Network pane to use "DHCP with manual address", wherein you enter a specific (static) IP address.
Forgot that DHCP with manual address thing. Thanks for the reminder.
 

macuser1232

macrumors 6502a
Original poster
Jan 20, 2012
666
3
oh ok. So there is no need to worry that my ip went from 192.168.1.xxx to 192.168.1.xxx. Ok thanks.
 
Nov 28, 2010
22,684
27
located
oh ok. So there is no need to worry that my ip went from 192.168.1.xxx to 192.168.1.xxx. Ok thanks.
There is no need to worry, as that is normal. Your router has a set range from 192.168.1.000 to 192.168.1.255, one reserved for the router itself and 255 others for all the devices connected to it. Since most consumers have less than 10 wireless clients connected to such router, the dynamic IP address stays almost always the same, giving the impression of a static IP.
 

arjen92

macrumors 65816
Sep 9, 2008
1,065
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Below sea level
Just for the information (although it's not that relevant anymore), my iMac is set to use DHCP but always has the same IP address because the router is set to always give this iMac the same static IP address (because I wanted to use it as a server). So even though the iMac is set to DHCP, the router will always give it the same IP address.
 

macuser1232

macrumors 6502a
Original poster
Jan 20, 2012
666
3
There is no need to worry, as that is normal. Your router has a set range from 192.168.1.000 to 192.168.1.255, one reserved for the router itself and 255 others for all the devices connected to it. Since most consumers have less than 10 wireless clients connected to such router, the dynamic IP address stays almost always the same, giving the impression of a static IP.
Being a curious guy myself, could you tell me why changing my home folder name would change the IP. Any ideas?

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Just for the information (although it's not that relevant anymore), my iMac is set to use DHCP but always has the same IP address because the router is set to always give this iMac the same static IP address (because I wanted to use it as a server). So even though the iMac is set to DHCP, the router will always give it the same IP address.
So you configured your router to do this? My router might have been like this as well but now the IP is changed.
 

ppc_michael

Guest
Apr 26, 2005
1,498
2
Los Angeles, CA
So you configured your router to do this? My router might have been like this as well but now the IP is changed.
Some routers (Airports included) can be set to reserve a specific IP address for a specific device (based on its MAC address). I do that. You can alternatively do it client-side by specifying a static IP, but if the router has already assigned that IP elsewhere, it won't work.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,417
752
There is an option in System Preferences > Network pane to use "DHCP with manual address", wherein you enter a specific (static) IP address. But someone would have had to choose this option (accidentally or intentionally), because the default is DHCP, i.e. DHCP with dynamically assigned address.
I just had to use this option yesterday with a client. With the "Using DHCP" there was a default IPv4 Address of 169.x.x.x that would allow connection to the WiFi network, but no internet connection, with the error about self-assigned IP address. Changing it to "Using DHCP with manual address" and entering a 192.168.x.x address resolved the issue. I'm certainly no expert when it comes to networking, so I don't fully understand why this worked, but it did.
 

macuser1232

macrumors 6502a
Original poster
Jan 20, 2012
666
3
I just had to use this option yesterday with a client. With the "Using DHCP" there was a default IPv4 Address of 169.x.x.x that would allow connection to the WiFi network, but no internet connection, with the error about self-assigned IP address. Changing it to "Using DHCP with manual address" and entering a 192.168.x.x address resolved the issue. I'm certainly no expert when it comes to networking, so I don't fully understand why this worked, but it did.
Renewing DHCP License would resolve the issue as well.
 

macuser1232

macrumors 6502a
Original poster
Jan 20, 2012
666
3
I had done that several times, with no success. Each time it came back to the 169.x.x.x address.
ohhh. So, anyway what does changing your computer's IP address do? Does it affect anything? And if my IP is dynamic does that mean it will only change when I reset my router?

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Oh and while your here, what is the NetBIOS name? Mine is NEW-HOST and I'm not sure if it should be changed or not.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,417
752
ohhh. So, anyway what does changing your computer's IP address do? Does it affect anything? And if my IP is dynamic does that mean it will only change when I reset my router?
First, there are "internal" and "external" IP addresses. For example, you may have a wireless network set up with internet access. All devices on your network could share one "external" IP address that uniquely identifies your network on the internet. In addition, each device on your network has an internal IP address, to uniquely identify that device on your wireless network.

Unless you're having a problem, you don't need to think about such things, as they're typically "behind the curtain", so to speak. If everything is working properly, it's best to leave things alone.
Oh and while your here, what is the NetBIOS name? Mine is NEW-HOST and I'm not sure if it should be changed or not.
NetBIOS Sorry you asked? :D
 

macuser1232

macrumors 6502a
Original poster
Jan 20, 2012
666
3
First, there are "internal" and "external" IP addresses. For example, you may have a wireless network set up with internet access. All devices on your network could share one "external" IP address that uniquely identifies your network on the internet. In addition, each device on your network has an internal IP address, to uniquely identify that device on your wireless network.

Unless you're having a problem, you don't need to think about such things, as they're typically "behind the curtain", so to speak. If everything is working properly, it's best to leave things alone.

NetBIOS Sorry you asked? :D
I understand internal and external ip's. Also, would you mind sharing what your NetBIOS name? To get it, click on Network in System Preferences. Then click Advanced and go to the WINS tab. There it will tell you the NetBIOS name.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,417
752
I understand internal and external ip's. Also, would you mind sharing what your NetBIOS name? To get it, click on Network in System Preferences. Then click Advanced and go to the WINS tab. There it will tell you the NetBIOS name.
I know where to find it, but knowing my settings won't help you at all. You really don't need to worry about it, but here's some more reading:

OS X Mountain Lion: Set advanced networking options
OS X Mountain Lion: Set WINS options

You seem to be fixated on all the inner workings of your computer, rather than just using it. That's the benefit of using Mac OS X: you don't have to keep tinkering and digging into the internals to make it work. Just use it. If you really are determined to understand all the "under the hood" stuff, you should consider taking some courses on Mac OS X. They're not necessary at all for a user to get the most out of their Mac, but if you find you can't leave it alone, that may be your best option.

Apple Training and Certification - Learn