I'm also on Win7 x64 using Docker 1.7.1 build 786b29d (Jul 15 2015) - is this a problem specific to Windows?

This problem was temporarily solved (for me) by setting the IP address options before creating the machine (see https://docs.docker.com/machine/#oracle-virtualbox CIDR options):

set VIRTUALBOX_HOSTONLY_CIDR=192.168.99.100/24

The docs don't explain this option very well, but basically 100 is the starting address and 24 is the number of addresses in the range to check if available. A note to the person above - use the Windows commands to get the environment values, as described in the docs. Specifically: 'docker-machine env --shell cmd dev', rather than the 'eval' command which required bsh or other scripting host. Delete the machine 'docker-machine rm dev' before trying the create again.

The logs to see which address is in conflict is available under Administrative Tools -> Event Viewer -> Windows Logs -> System:
"The system detected an address conflict for IP address 192.168.99.1 with the system having network hardware address 08-00-27-F8-37-24. Network operations on this system may be disrupted as a result."

Interestingly, boot2docker does not have this problem. It picks address 192.168.99.100 to start with.

However (in a large corporate environment where hundred of developer machines share the same network) docker really should check for an unused IP address conflict before grabbing an address during launch.

I had a this same problem with creating and starting machines with Docker-Machine (or Kitematic):

• Machine creation never completes (99% in Kitematic and hangs on command line)
• new Host-Only network adapter is created
• Windows Duplicate IP Error is raised
• VirtualBox shows the Machine as running
• docker-machine config and Kitematic (may need to close and reopen) gives ...

  ENOENT: no such file or directory, open 'C:\Users\ca.pem'

• Can't ping VM, but can ssh to it.

Have previously had no issues creating several machines with boot2docker (v1.8.0 and before) so looked for differences in the newly Host-Only network adapters.
Appears to be that in docker-machine created adapters the interface host adapter address and the DHCP server address are the same.

Secondary Problem
Any change to Host-Only interface settings results in creation of another interface with the same issue when restarting from Docker-Machine or Kitematic (similar to #1804)

The workaround was to use different IPs for the adapter Host and DHCP server settings, then start the machine from VBoxManage, from then on all docker and docker-machine commands work as expected.

VBoxManage.exe startvm docker-vm --type headless
docker-machine env docker-vm --shell cmd>%userprofile%\dockerConfig.bat
call %userprofile%\dockerConfig.bat
docker-machine ssh docker-vm "sudo mkdir -p /vmdata/ & sudo mount -t vboxsf vmdata /vmdata/"

Things working fine now for a few days and several reboot / restart cycles

• Win7x64
• VirtualBox 4.3.26
• Docker-Machine 0.4.0

Duplicate of #1673
The Fix was merged Aug. 28 - #1674

A release with fixes would be nice.

@gmanfunky The release will be out in about two weeks' time. In the meantime, you can get master builds at https://docker-machine-builds.evanhazlett.com/latest (we will host an official version eventually as well) or compiling from source.

Thanks!

• N

@nathanleclaire The link you posted sadly has no builds, any idea where I can find them?

@michaeltricht Looks like the unofficial master binaries are having a hiccup -- in the interim your best bet is to build yourself from source.