Switching subnet /24 to /23
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@JaredBusch said:
This is easy, you just have to plan it out. Note, you cannot "change" the scope of your DHCP server. You can choose to add another or wipe it and reimport it via PowerShell (what I typically do).
- Understand what your new range will be. Since you are on X.X.1.X/24. the new scope will be X.X.0.X/23.
- Update your router LAN IP to use the /23. If it was X.X.1.1/24, it is now X.X.1.1/23.
- Update your DC (asusming a WIndows network here) to use the new /23.
- Put a test device manually on X.X.0.X/23 and make sure you have internet and can ping the DC.
- Update all of your static devices to the /23.
- Export the DHCP Scope via PowerShell
Export-DhcpServer -ComputerName dhcpserver.contoso.com -File C:\exportdir\dhcpexport.xml - Edit the XML file to expand the scope. Here is an example of one I did this on a couple years ago. Basically change the ScopeID, SubnetMask, StartRange, and add an ExclusionRange for the entire X.X.0.1-X.X.0.255 initially. You can delete this exclusion in the GUI later when you are ready to use it.
- Delete your current DHCP scope from the GUI.
- Import the updated scope from PowerShell.
Import-DhcpServer -ComputerName dhcpserver.contoso.com -File C:\exports\dhcpexport.xml. - Refresh the GUI, enable the scope, restart the service, etc.
- Make sure all the settings migrated in correctly.
- Force a machine to DHCP renew and you are done.
Does this looks about right? 1.1-1.30 belong to current static IP addresses
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@LAH3385 You noted the subnetmask as a /22 but noted the end range as 1.254. The end range of a /22 is 3.254.
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Am I reading that right that you want to to exclude the entire 192.168.0.1/24 subnet?
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@coliver said:
Am I reading that right that you want to to exclude the entire 192.168.0.1/24 subnet?
For the time being. yes. It will be open to public later. I don't have a solid game plan yet so might as well keep everything the way it is (starting at .1.xx)
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@LAH3385 said:
@coliver said:
Am I reading that right that you want to to exclude the entire 192.168.0.1/24 subnet?
For the time being. yes. It will be open to public later. I don't have a solid game plan yet so might as well keep everything the way it is (starting at .1.xx)
Ah, ok I was just checking.
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@coliver said:
@LAH3385 said:
@coliver said:
Am I reading that right that you want to to exclude the entire 192.168.0.1/24 subnet?
For the time being. yes. It will be open to public later. I don't have a solid game plan yet so might as well keep everything the way it is (starting at .1.xx)
Ah, ok I was just checking.
It is what I told him to do for the immediate change over. I suggested it, because every time I open up a range, I find something that was missed and suddenly people cannot do whatever task they need to.
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@JaredBusch
To make it simpler for me. Would /22 starting at 192.168.1.1 to 192.168.4.254 better than 192.168.0.1 to 192.168.3.254? -
@LAH3385 said:
@JaredBusch
To make it simpler for me. Would /22 starting at 192.168.1.1 to 192.168.4.254 better than 192.168.0.1 to 192.168.3.254?The /22 network that include 192.168.4.1 is 192.168.4.0-192.168.7.254.
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@LAH3385 said:
@JaredBusch
To make it simpler for me. Would /22 starting at 192.168.1.1 to 192.168.4.254 better than 192.168.0.1 to 192.168.3.254?it doesn't work that way. You don't get to pick which addresses are part of your /22, the layout of bits in the subnet mask do.
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Here is a page that talks about how subnetting works, and why it works how it does.
https://www.techopedia.com/6/28587/internet/8-steps-to-understanding-ip-subnetting/3 -
I see.. Gotta play by their rules.
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@LAH3385 said:
I see.. Gotta play by their rules.
Look at the screenshot provided above, it shows you the range.
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@LAH3385 said:
I see.. Gotta play by their rules.
Lol thier rules? You're kidding right?
This is all math and the way binary works... They are not just made up rules someone randomly decided to make.
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@Dashrender said:
They are not just made up rules someone randomly decided to make.
lies! it is magic!
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