Change Hyper-V (Default Switch) IP address range

Question

Hello,

Is it possible to change the IP address range used by the Hyper-V (Default Switch) that is 172.x.x.x to 192.168.x.x ?

This is for Hyper-V on windows 10 1809 to 1909

Thread source link: https://social.technet.microsoft.com/Forums/windowsserver/en-US/6b2a9042-c590-4b5d-aa4c-60eb3f7901e8/change-hyperv-default-switch-ip-address-range?forum=winserverhyperv

Answer 1

Hi LMichel,

We are unable to remove default Switch on windows 10 and unable to change the IP address range.

"The Hyper-V Default Switch will randomly use one these IP address ranges based on the host system IP address:

• Start IP: 192.168.0.0 – End IP: 192.168.255.255
• Start IP: 172.17.0.0 – End IP: 172.31.255.255

The Default Switch has a built-in local collision detection mechanism to determine if IP address in these ranges is already assigned to a network interface on the Local Host system and will try to find a (/28 – 255.255.255.240) address space within one of these ranges that is not already allocated to any network interfaces.

The Default Switch on the Host system always assign the first IP address of the chosen range to the virtual Ethernet Adaptor on the Host, and use this address as the Default Gateway and DNS server provided to the hosted VMs connected to it.

You cannot remove or manage "DHCP" on the default switch."

Thanks for your time!

Best Regards,

Answer 2

I am not sure if this staement
will try to find a (/28 – 255.255.255.240)
is correct
In my envirenment, Default switch configured itself with the subnet

172.22.0.0 mask 225.225.240.0

its ip is
172.22.144.1

1st machine IP is
172.22.159.156 mask 255.255.240.0

broadcast ip
172.22.159.255

Answer 3

This is far from ideal solution, however it may be suitable for some given that I've found it a real headache of an issue.

Powershell will let you change the parameters of the Default Switch, however it'll get overwritten at next boot. Therefore one option is to put the Powershell script in the startup.

Warning Note!!! This script will remove all related IP's from the Adapter before applying the new settings, also please ensure your NIC is named exactly as listed here "vEthernet (Default Switch)" and you obviously want to change the addresses to those suited to your needs.

Get-NetIPAddress -InterfaceIndex (Get-NetAdapter -Name 'vEthernet (Default Switch)').ifIndex | Remove-NetIPAddress
New-NetIPAddress -InterfaceAlias 'vEthernet (Default Switch)' -IPAddress '10.0.0.1' -PrefixLength 24
Set-DnsClientServerAddress -InterfaceAlias 'vEthernet (Default Switch)' -ServerAddresses ("10.0.0.15","8.8.8.8")

These commands can be expanded upon to set other parameters as needed, also i'm using static IP's everywhere as I got sick of these random IP's so I haven't tested using this setup as a DHCP server.

Hopefully it's of use to someone :)

Answer 4

@Xiaowei He I can confirm the above statement. I could live with a /28, but a /20 smack in the middle of my IP address plan (172.20.0.0/14 so far) is really annoying.
The reason people used the 172.16/12 address range was that few other system used that: SoHos were on 192.168/16, Enterprises were on 10/8, so 172.16/12 was the obvious choice.
I also understand that newer system try to avoid conflicts by using 172.16/12, like docker does. But at least your Unix peers a) use only a /16 and b) make it configurable and c) start near the beginning of the range, which I explicitly avoided, fearing that others might catch up. Took you long enough, though

That's just another bullet point on a presentation to my re-trainees: "I teach you Windows because it's everywhere and works quite well in most cases, BUT...."

Answer 5

Added confirm false at the end of your first line, this made startup work for me so it does not have to ask you everytime, just runs. Thanks again for this!

Get-NetIPAddress -InterfaceIndex (Get-NetAdapter -Name 'vEthernet (Default Switch)').ifIndex | Remove-NetIPAddress -confirm:$false
New-NetIPAddress -InterfaceAlias 'vEthernet (Default Switch)' -IPAddress '10.0.0.1' -PrefixLength 24
Set-DnsClientServerAddress -InterfaceAlias 'vEthernet (Default Switch)' -ServerAddresses ("10.0.0.15","8.8.8.8")