Docker IP Address Problem

September 18th, 2016

Docker is cool.  It provides a lot of features and paths to expand without using a lot of systems.  Where you once had to build out a system and configure each server the way it was needed, you now just have to configure a new Docker instances and that is very much like a Virtual Machine.  Note they are not a Virtual Machine but are a combination of a VM and a native application.

One issue that came up on a project I worked on was related to the process communication with the Docker images.  The problem turned out to be a conflict with the IP address range that was used on the internal network.  If I pinged the docker instance it was really pining some random box in the network not bridging to the on machine docker instance. After several days of searching the internet i finally got the right word combination that helped locate the real issue.

  • Under Linux look in the /etc/default/docker file.
  • in the DOCKER OPTS add or change something like the following
  • DOCKER_OPTS=”foo –bip=″
  • the “bip” entry changes the default bridge network to use the 10 dot network.