NetworkDriver.CreateNetwork: 172.20.0.1/16 has host bits set

[adrian-stephens]

Fresh git clone of project
make install
docker network create -d devplayer0/net-dhcp:latest --ipam-driver=null -o bridge=br0 test-net

returns: Error response from daemon: NetworkDriver.CreateNetwork: 172.20.0.1/16 has host bits set
The address is that of my docker0 network.
644: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
link/ether 02:42:6c:62:49:62 brd ff:ff:ff:ff:ff:ff
inet 172.20.0.1/16 brd 172.20.255.255 scope global docker0
valid_lft forever preferred_lft forever

docker --version: Docker version 19.03.8, build afacb8b7f0

I realise this is not enough to work on. Happy to provide additional information, I'm just not sure what would be useful here.

[devplayer0]

Hmmmm, it would seem the Subnet value for the IPAM section of the built-in Docker network has an IP set somehow (my Python code assumes it's only ever a CIDR subnet without the host bits set). The Go code I've written so far should ™️ account for this.

docker-net-dhcp/net-dhcp/network.py

Line 50 in 866bb1b

reserved_nets = set(map(ipaddress.ip_network, map(lambda c: c['Subnet'], \

I'll see if I can reproduce this behaviour with Docker on my end and test it. If you're still interested, would you mind describing your Docker environment (OS, have you made any config changes etc).