Change the IP range used by Docker

This page indicates how to change the IP ranges used by Docker.

By default, docker will use these two ranges:

• 172.17.0.0/16: for the bridge network (also called docker0)
• 172.18.0.0/16: for the docker_gwbridge network

If the procedure is followed during the installation of Cyberwatch, only steps 3 and 4 are necessary.

1. Stop the instance:

   sudo cyberwatch stop
   

2. Disconnect and remove network docker_gwbridge

   docker network disconnect -f docker_gwbridge gateway_ingress-sbox
   docker network rm docker_gwbridge
   

3. Edit file /etc/docker/daemon.json:

   {
     "bip": "10.0.64.1/24",
     "default-address-pools": [
       { "base": "10.0.64.0/18", "size": 24 }
     ]
   }
   

   The field bip (Bridge IP) defines the IP range that network interface docker0 can use. The example reserves IP range 10.0.64.1/24 to the interface. Beware, the range must end with .1, otherwise docker won’t start.

   The field default-address-pools defines the IP range of network interface docker_gwbridge. The example reserves IP range 10.0.64.0/18.

4. Restart docker:

   sudo systemctl restart docker
   

5. Start Cyberwatch:

   sudo cyberwatch start
   

6. Check that the IPs changed:

   docker network inspect bridge | grep Subnet
   docker network inspect docker_gwbridge | grep Subnet