default-address-pools

default-address-pools

MCR uses three separate IP ranges for the docker0, docker_gwbridge, and ucp-bridge interfaces. By default, MCR assigns the first available subnet in default-address-pools (172.17.0.0/16) to docker0, the second (172.18.0.0/16) to docker_gwbridge, and the third (172.18.0.0/16) to ucp-bridge.

Note

The ucp-bridge bridge network specifically supports MKE component containers.

You can reassign the docker0, docker_gwbridge, and ucp-bridge subnets in default-address-pools. To do so, replace the relevant values in default-address-pools, making sure that the setting includes at least three IP pools.

By default, default-address-pools contains the following values:

{
  "default-address-pools": [
   {"base":"172.17.0.0/16","size":16}, <-- docker0
   {"base":"172.18.0.0/16","size":16}, <-- docker_gwbridge
   {"base":"172.19.0.0/16","size":16}, <-- ucp-bridge
   {"base":"172.20.0.0/16","size":16},
   {"base":"172.21.0.0/16","size":16},
   {"base":"172.22.0.0/16","size":16},
   {"base":"172.23.0.0/16","size":16},
   {"base":"172.24.0.0/16","size":16},
   {"base":"172.25.0.0/16","size":16},
   {"base":"172.26.0.0/16","size":16},
   {"base":"172.27.0.0/16","size":16},
   {"base":"172.28.0.0/16","size":16},
   {"base":"172.29.0.0/16","size":16},
   {"base":"172.30.0.0/16","size":16},
   {"base":"192.168.0.0/16","size":20}
   ]
 }
The default-address-pools parameters

Parameter

Description

default-address-pools

The list of CIDR ranges used to allocate subnets for local bridge networks.

base

The CIDR range allocated for bridge networks in each IP address pool.

size

The CIDR netmask that determines the subnet size to allocate from the base pool. If the size matches the netmask of the base, then the pool contains one subnet. For example, {"base":"172.17.0.0/16","size":16} creates the subnet: 172.17.0.0/16 (172.17.0.1 - 172.17.255.255).

For example, {"base":"192.168.0.0/16","size":20} allocates /20 subnets from 192.168.0.0/16, including the following subnets for bridge networks:

192.168.0.0/20 (192.168.0.1 - 192.168.15.255)

192.168.16.0/20 (192.168.16.1 - 192.168.31.255)

192.168.32.0/20 (192.168.32.1 - 192.168.47.255)

192.168.48.0/20 (192.168.48.1 - 192.168.63.255)

192.168.64.0/20 (192.168.64.1 - 192.168.79.255)

192.168.240.0/20 (192.168.240.1 - 192.168.255.255)