Comment 1 for bug 1618698

One more observation that

***When docker is run through tcp://0.0.0.0:2375 ***
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vagrant@devstack:~/devstack$ sudo netstat -anlpto | grep "docker"
tcp 0 0 127.0.0.1:36101 127.0.0.1:4001 ESTABLISHED 7268/dockerd keepalive (12.90/0/0)
tcp 0 0 127.0.0.1:36100 127.0.0.1:4001 ESTABLISHED 7268/dockerd keepalive (12.90/0/0)
tcp6 0 0 :::2375 :::* LISTEN 7268/dockerd off (0.00/0/0)
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vagrant@devstack:~/devstack$ sudo /usr/bin/docker daemon -H tcp://0.0.0.0:2375 --cluster-store etcd://localhost:4001 & echo $! >/opt/stack/status/stack/docker-engine.pid; fg || echo "docker-engine failed to start" | tee "/opt/stack/status/stack/docker-engine.failure"
[1] 7267
sudo /usr/bin/docker daemon -H tcp://0.0.0.0:2375 --cluster-store etcd://localhost:4001
WARN[0000] [!] DON'T BIND ON ANY IP ADDRESS WITHOUT setting -tlsverify IF YOU DON'T KNOW WHAT YOU'RE DOING [!]
INFO[0000] libcontainerd: new containerd process, pid: 7276
WARN[0000] containerd: low RLIMIT_NOFILE changing to max current=1024 max=4096
INFO[0001] [graphdriver] using prior storage driver "aufs"
INFO[0001] Graph migration to content-addressability took 0.00 seconds
WARN[0001] Your kernel does not support swap memory limit.
WARN[0001] mountpoint for pids not found
INFO[0001] Loading containers: start.
INFO[0001] Firewalld running: false
INFO[0001] Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address

INFO[0001] Loading containers: done.
INFO[0001] Daemon has completed initialization
INFO[0001] Docker daemon commit=23cf638 graphdriver=aufs version=1.12.1
INFO[0001] API listen on [::]:2375

***When docker is run through tcp://127.0.0.1:2375 ***
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vagrant@devstack:~/devstack$ sudo netstat -anlpto | grep "docker"
tcp 0 0 127.0.0.1:2375 0.0.0.0:* LISTEN 5435/dockerd off (0.00/0/0)
tcp 0 0 127.0.0.1:36083 127.0.0.1:4001 ESTABLISHED 5435/dockerd keepalive (13.90/0/0)
tcp 0 0 127.0.0.1:36084 127.0.0.1:4001 ESTABLISHED 5435/dockerd keepalive (13.13/0/0)
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vagrant@devstack:~/devstack$ sudo /usr/bin/docker daemon -H tcp://127.0.0.1:2375 --cluster-store etcd://localhost:4001 & echo $! >/opt/stack/status/stack/docker-engine.pid; fg || echo "docker-engine failed to start" | tee "/opt/stack/status/stack/docker-engine.failure"
[1] 5434
sudo /usr/bin/docker daemon -H tcp://127.0.0.1:2375 --cluster-store etcd://localhost:4001
WARN[0000] [!] DON'T BIND ON ANY IP ADDRESS WITHOUT setting -tlsverify IF YOU DON'T KNOW WHAT YOU'RE DOING [!]
INFO[0000] libcontainerd: new containerd process, pid: 5444
WARN[0000] containerd: low RLIMIT_NOFILE changing to max current=1024 max=4096
INFO[0001] [graphdriver] using prior storage driver "aufs"
INFO[0001] Graph migration to content-addressability took 0.00 seconds
WARN[0001] Your kernel does not support swap memory limit.
WARN[0001] mountpoint for pids not found
INFO[0001] Loading containers: start.
INFO[0001] Firewalld running: false
INFO[0001] Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address

INFO[0001] Loading containers: done.
INFO[0001] Daemon has completed initialization
INFO[0001] Docker daemon commit=23cf638 graphdriver=aufs version=1.12.1
INFO[0001] API listen on 127.0.0.1:2375

Would it make a difference ?
127.0.0.1:2375 0.0.0.0:*
                   vs
0 :::2375 :::*