Configuring the IP Address for the Docker Interface

From ESA v9.0.0.0, the default IP addresses assigned to the docker interfaces are between 172.17.0.0/16 and 172.18.0.0/16. If your have a VPN or your organization’s network configured with the IP addresses are between 172.17.0.0/16 and 172.18.0.0/16, then this might cause conflict with your organization’s private or internal network resulting in loss of network connectivity.

Note: Ensure that the IP addresses assigned to the docker interface must not conflict with the organization’s private or internal network.

To verify if there is any IP conflict between docker interface and organization’s private or internal network, run the following command to see the current IP range of the organization’s private or internal network.

ip addr show ethMNG

If the network’s subnet overlaps with Docker’s default range, a conflict exists.

In such a case you can reconfigure the IP addresses for the docker interface by performing the following steps.

To configure the IP address of the docker interfaces:

1. Remove docker_gwbridge network using the following command.

   docker network rm docker_gwbridge
   

2. In the /etc/docker/daemon.json file, enter the non-conflicting IP address range.

   Note:

   You must separate the entries in the daemon.json file using a comma (,). Before adding new entries, ensure that the existing entries are separated by a comma (,). Also, ensure that the entries are enlisted in the correct as shown in the following example .

   "bip": "10.200.0.1/24",
   "default-address-pools":
   [
     {"base":"10.201.0.0/16","size":24}
   ]
   

   Warning:

   If the the entries in the file are not mentioned in the format specified in step 3, then the restart operation for docker service fails.

3. Restart the docker service using the following command.

   /etc/init.d/docker restart
   

   The docker service is restarted successfully.

4. Check the status of the docker service using the following command.

   /etc/init.d/docker status
   

5. Verify the updated IP for the docker service using the following command.

   ip addr show docker0
   

   The IP address of the docker interfaces are changed successfully.