IPv6 address pool only yields a single subnet #41438
Description
Description
The core address pool functionality of automatically dividing a larger subnet into smaller subnets to assign to networks only seems to work for IPv4. IPv6 pools yield one subnet, after which Docker claims that no non-overlapping subnets are available.
Steps to reproduce the issue:
-
Use the following dockerd configuration:
{ "default-address-pools": [ {"base": "172.17.0.0/16", "size": 24}, {"base": "fd00:dead:beef::/48", "size": 64} ] } -
docker network create --ipv6 ipv6test1 -
docker network create --ipv6 ipv6test2
Describe the results you received:
The first network is created succesfully. Creating the second network fails:
Error response from daemon: could not find an available, non-overlapping IPv6 address pool among the defaults to assign to the network
Describe the results you expected:
Two IPv6 networks are created and assigned a /64 subnet from the pool.
Additional information you deem important (e.g. issue happens only occasionally):
Manually providing multiple pools works around the error, for example:
"default-address-pools": [
{"base": "172.17.0.0/16", "size": 24},
{"base": "fd00:fefe:1::/48", "size": 64},
{"base": "fd00:fefe:2::/48", "size": 64},
{"base": "fd00:fefe:3::/48", "size": 64},
{"base": "fd00:fefe:4::/48", "size": 64}
]
However, each pool is still only used once, so in the above example only four IPv6 networks can be created.
Output of docker version:
Client: Docker Engine - Community
Version: 19.03.12
API version: 1.40
Go version: go1.13.10
Git commit: 48a66213fe
Built: Mon Jun 22 15:45:50 2020
OS/Arch: linux/amd64
Experimental: false
Server: Docker Engine - Community
Engine:
Version: 19.03.12
API version: 1.40 (minimum version 1.12)
Go version: go1.13.10
Git commit: 48a66213fe
Built: Mon Jun 22 15:44:21 2020
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.2.13
GitCommit: 7ad184331fa3e55e52b890ea95e65ba581ae3429
runc:
Version: 1.0.0-rc10
GitCommit: dc9208a3303feef5b3839f4323d9beb36df0a9dd
docker-init:
Version: 0.18.0
GitCommit: fec3683
Output of docker info:
Server:
Containers: 5
Running: 5
Paused: 0
Stopped: 0
Images: 6
Server Version: 19.03.12
Storage Driver: overlay2
Backing Filesystem: extfs
Supports d_type: true
Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host ipvlan macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 7ad184331fa3e55e52b890ea95e65ba581ae3429
runc version: dc9208a3303feef5b3839f4323d9beb36df0a9dd
init version: fec3683
Security Options:
apparmor
seccomp
Profile: default
Kernel Version: 4.19.0-10-cloud-amd64
Operating System: Debian GNU/Linux 10 (buster)
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 989.9MiB
Name: <redacted>
ID: <redacted>
Docker Root Dir: /var/lib/docker
Debug Mode: false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
WARNING: No swap limit support