Network error on Vagrant up since VirtualBox 6.1.28

[JoosuaKoskinen]

Output from vagrant up after upgrading to VirtualBox >= 6.1.28:

▶ vagrant up
Bringing machine 'wordpress-box' up with 'virtualbox' provider...
==> wordpress-box: Importing base box 'seravo/wordpress-beta'...
==> wordpress-box: Matching MAC address for NAT networking...
==> wordpress-box: Checking if box 'seravo/wordpress-beta' version '20210317.0.0' is up to date...
==> wordpress-box: [vagrant-hostsupdater] Checking for host entries
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 wordpress
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 wordpress.local
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 www.wordpress.local
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 webgrind.wordpress.local
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 adminer.wordpress.local
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 mailcatcher.wordpress.local
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 browsersync.wordpress.local
==> wordpress-box: [vagrant-hostsupdater]   found entry for: 192.168.250.175 info.wordpress.local
==> wordpress-box: Setting the name of the VM: wordpress_wordpress-box_1637946275051_15025
==> wordpress-box: Clearing any previously set network interfaces...
The IP address configured for the host-only network is not within the
allowed ranges. Please update the address used to be within the allowed
ranges and run the command again.

  Address: 192.168.250.175
  Ranges: 192.168.56.0/21

Valid ranges can be modified in the /etc/vbox/networks.conf file. For
more information including valid format see:

  https://www.virtualbox.org/manual/ch06.html#network_hostonly

Reported by a customer on 6.1.28. I managed to reproduce after upgrading from 6.1.26 to 6.1.30. Tried vagrant destroy and changing 192.168.250 in Vagrantfile but no effect. Maybe requires removing old VirtualBox interfaces, I have tons of them.

[JoosuaKoskinen]

From VirtualBox 6.1.28 changelog:

Network: More administrative control over host-only network ranges to prevent trouble due to misconfiguration, see user manual. Check updated documentation or your VMs may stop working!

[JoosuaKoskinen]

The updated VirtualBox documentation has the following:

On Linux, Mac OS X and Solaris Oracle VM VirtualBox will only allow IP addresses in 192.168.56.0/21 range to be assigned to host-only adapters.

Changing IP to something between 192.168.56.0 and 192.168.63.255 in Vagrantfile actually does fix this if you remove ./.vagrant/private.ip before vagrant up.

As the VirtualBox documentation states that the IP should be in that range, I think we should do the change.