Default network address¶

If you have issues related to the default network address configuration, cURL either hangs or the following error occurs:

curl: (7) Failed to connect to xxx.xxx.xxx.xxx port xxxx: Host is unreachable

The issue may occur because the default Docker network address 172.17.0.0/16 and/or the kind Docker network, which is used by kind, overlap with your cloud address or other addresses of the network configuration.

Workaround:

Log in to your local machine.
Verify routing to the IP addresses of the target cloud endpoints:
1. Obtain the IP address of your target cloud. For example:
```
nslookup auth.openstack.example.com
```
  Example of system response:
```
Name:   auth.openstack.example.com
Address: 172.17.246.119
```
2. Verify that this IP address is not routed through docker0 but through any other interface, for example, ens3:
```
ip r get 172.17.246.119
```
  Example of the system response if the routing is configured correctly:
```
172.17.246.119 via 172.18.194.1 dev ens3 src 172.18.1.1 uid 1000
  cache
```
  Example of the system response if the routing is configured incorrectly:
```
172.17.246.119 via 172.18.194.1 dev docker0 src 172.18.1.1 uid 1000
  cache
```
If the routing is incorrect, change the IP address of the default Docker bridge:
1. Create or edit /etc/docker/daemon.json by adding the "bip" option:
```
{
  "bip": "192.168.91.1/24"
}
```
2. Restart the Docker daemon:
```
sudo systemctl restart docker
```
If required, customize addresses for your kind Docker network or any other additional Docker networks:
1. Remove the kind network:
```
docker network rm 'kind'
```
2. Choose from the following options:
  - Configure /etc/docker/daemon.json:
    
    Note
    
    The following steps are applied to to customize addresses for the kind Docker network. Use these steps as an example for any other additional Docker networks.
    1. Add the following section to /etc/docker/daemon.json:
      { "default-address-pools": [ {"base":"192.169.0.0/16","size":24} ] }
    2. Restart the Docker daemon:
      sudo systemctl restart docker
      After Docker restart, the newly created local or global scope networks, including 'kind', will be dynamically assigned a subnet from the defined pool.
  - Recreate the 'kind' Docker network manually with a subnet that is not in use in your network. For example:
    docker network create -o com.docker.network.bridge.enable_ip_masquerade=true -d bridge --subnet 192.168.0.0/24 'kind'
    Caution
    
    Docker pruning removes the user defined networks, including 'kind'. Therefore, every time after running the Docker pruning commands, re-create the 'kind' network again using the command above.