I have a webservice running inside a docker instance which was run using the following command:

sudo docker run -d -p 4040:4040 ....

My UFW rules look like this:

~ sudo ufw status
Status: active

To                         Action      From
--                         ------      ----
22                         ALLOW       Anywhere
4040                       DENY        Anywhere
22                         ALLOW       Anywhere (v6)
4040                       DENY        Anywhere (v6)

When I access the box directly via its IP, I can access port 4040. Why is the ufw rule not blocking it?

Note: As part of the docker installation, I changed


in /etc/default/ufw as per dockers instructions here (http://docs.docker.io/en/latest/installation/ubuntulinux/#docker-and-ufw)


I had the same problem and resolved it by using IPTABLES instead.

Example to only allow 3306 from source ip xxx.xxx.xxx.xxx:

Adds an accept for source matching our ip to line 1 of the FORWARD chain

iptables -I FORWARD 1 -p tcp -i eth0 -s xxx.xxx.xxx.xxx --dport 3306 -j ACCEPT

Drops all other connections on the FORWARD chain for that port

iptables -I FORWARD 2 -p tcp -i eth0 --dport 3306 -j DROP

Using the line numbers (1 & 2) forces the rules to be added above the ones created by docker such as:

-A FORWARD -d ! -i docker0 -o docker0 -p tcp -m tcp --dport 3306 -j ACCEPT

| improve this answer | |
  • Be ware: when restarting the container the newly created container will be prepended onto those IP table rules thus you have to re initialize those exact same iptable changes... – Gekkie Nov 3 '14 at 15:21

There is a know issue related with this. Basically, docker is configuring Iptables behind UFW.

More information:

The short possible response:

Set DEFAULT_FORWARD_POLICY="ACCEPT" in /etc/default/ufw
Set DOCKER_OPTS="--iptables=false" in /etc/default/docker
| improve this answer | |

Try running the container with a specific IP.

docker run -d -p ...
| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.