Subnet incrementing (docker broken after docker prune?)

[mx2k]

I have posted this to a closed issue, not sure if anyone reads there, so I have created a new issue.

  > I think normally you'd do a `docker network prune`.

Hello, I had the same issue with Portainer managing Docker on my Synology NAS. I did run docker network prune. I was expecting new stacks to get their networks starting at 172.17.0.0/16, as the original poster also expected.

However, new networks created from running stacks are now getting their default IPAM IPs like this:
subnet: 192.168.16.0/20 gateway: 192.168.16.1

Is this ok too or have I broken my docker installation? Can I revert this so that ist back in the "docker default" network range of 172.17.0.0/16? I mean both IP ranges point to private network segments, but all docker tutorials kinda use the 172.xx.xx.xx networks.

I made a screenshot to clarify: https://imgur.com/8JCTjy4

edit: other sources indicate an IP range of 192.168.16.x might relate to macvlan networks. I checked the network in Portainer and it definitely says it runs in bridge driver mode.

edit2: not sure if this is relevant, but the docker networks on the NAS get the container IPs by DHCP (at least it's set to get IP automatically on network generation, which gives me the 192.168.16.0/20 range. Here the increment is even worse, next network I made was at 192.168.32.0/20)

Originally posted by @mx2k in #6237 (comment)

[tamarahenson]

@mx2k

I ran docker network prune and my existing nor new containers are not in the 192.168.xx.xx on my Docker Standalone VM.

I am seeing here that my stack networks are in the 172.2x.xx range:

My containers are in the 172.17.xx.xx:

I am going to continue to investigate. More to follow.

Thanks!

[tamarahenson]

I manually created a wordpress Stack via docker compose up and my network is in 172.28.xx.xx. This is appearing to be Docker behavior and not Portainer.

Thanks!