HowTo:Docker 172 Fix

Background

VT uses a chunk of the 172 private network address space for it's internal private addressing. Docker comes pre-configured to also uses 172.17.0.0/12 which will cause the internal system to ignore any external 172.17.x.x/12 address trying to access the system. To fix this you need to reconfigure your docker to use a different address space like 192.168.x.x/16 or a 10.1.x.x/16 (tech also uses 10.6+.x.x for their networking so this is less safe although 10.5 and lower are guaranteed to be free).

The Fix

To apply the docker fix, create a file called /etc/docker/daemon.json with the following:

{
  "iptables": false
  "default-address-pools":
  [
    {"base":"10.1.0.0/16","size":24}
  ]
}

Followed by:

sudo service docker restart