If you check the official documentation ( https://docs.docker.com/v1.5/articles/networking/), a first solution is given to limit Docker container access to one particular IP. iptables -I DOCKER ! The same command structure can be used to allow traffic to other ports as well. The key in your configuration is this line - -A DOCKER ! Step 3 : Add/Remove an Iptable rule Once we are aware of the rules that are currently configured,We can open a port in IPtables by adding a rule using below command. This is because of the way Docker interacts with iptables: By default, it exposes ports to the whole world, not just to localhost! # 1. It's a private IP address range, so there's minimal risk in having it open. You can allow port access to all containers or specific container. Container networking. To add a rule to the firewall, invoke the iptables command as follows: # iptables -A chain_name criteria -j target where, -A stands for Append (append the current rule to the end of the chain). So I added similar rules to allow my container to access other host ports desired, which I think could be a bit more precise way to open host network access to containers. FirewallD is the default firewall application on Fedora, CentOS and other Linux distributions that are based on them. dockeriptablesDOCKER chain dockerip request IP docker run DOC --publish , -p Publish a container's port (s) to the host --publish-all , -P Publish all exposed ports to random ports target is the action, or policy, to apply in this case (ACCEPT, REJECT, or DROP). We expose Docker Ports 80 (HTTP) and 443 (HTTPS) of an NGINX docker container and want to allow access to this ports only by named IP addresses or subnets. This happens before the filter rules, so --dest and --dport will see the internal IP and port of the container. Open ports based on your needed. If you prevent Docker from adding iptables rules, Docker will also not add IP masquerading rules, even if you set --ip-masq to true. 4. Create a set of docker containers with exposed ports Check the firewall; docker will by use "anywhere" as the source, thereby all containers are exposed to the public. For simplicity, I give commands to allow all (ipv4 and ipv6, TCP and UDP from all interfaces) using port 3389 as an example. # allow TCP ipv4 iptables -I INPUT -p tcp --dport 3389 -j ACCEPT # allow UDP ipv4 iptables -I INPUT -p udp --dport 3389 . If multiple daemons manage iptables rules, they may overwrite rules set by another daemon. File name in below command can be anything. Stop Docker systemctl stop docker # 2. To allow only a specific IP or network to access the containers, insert a negated rule at the top of the DOCKER filter chain. Be aware that disabling this option requires you to manually add iptables rules to expose container ports. Docker and iptables. Share. Here are the commands you will run to allow all traffic coming onto the loopback interface: 1 2 sudo iptables - A INPUT - i lo - j ACCEPT sudo iptables - A OUTPUT - o lo - j ACCEPT Established and Related Incoming Connections Another type of connection that you may need to allow is the outgoing connection. By default only ssh access to local machine is allowd. any address on the host. -s ipyouwanttoallow -j DROP accept all connections from your container local IP to the world iptables -I DOCKER -s localipofyourcontainer -d 0.0.0.0/0 -j ACCEPT necessary to allow external servers to answer your container requests iptables -I DOCKER -m state --state ESTABLISHED,RELATED -j ACCEPT Share Improve this answer By now, we have set up the the iptables rules for forwarding the 80 port. sudo iptables -A INPUT -p tcp --dport xxxx -j ACCEPT Note Replace xxxx with required port number you wish to open For example to open a Mysql port 3306,We need to run below command. Given a fairly common firewall setup with nftables/iptables (OUTPUT accept, INPUT/FORWARD accept established+related, default drop): table ip nat { chain DOCKER { iifname "docker0" return iifname != "docker0" meta l4proto tcp ip daddr 172.17..1 tcp dport 5000 dnat to 172.17..2:5000 iifname != "docker0" meta l4proto tcp ip daddr 127.0.0.1 . 1 sudo ufw route allow proto tcp from any to any port 8080 Allow public access to port 80 for container with private address 172.17..3 1 ufw route allow proto tcp from any to 172.17..3 port 80 Allow DNS 1 Save iptables to a file. The rule is -A IN_public_allow -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW -j ACCEPT. To do this we don't have to, but it's easier to create our own network in the long run as docker does not let us specify a container's IP on the default network. So let's enable it and add the network ports necessary for Docker Swarm to function. The server has 2 ips, a public ip (on interface enp0s8) and a private ip (on interface tun0, which is only accessible through a vpn).I want to configure iptables in a way to only allow access for ports 80 and 443 through the public interface but allow all ports through the vpn interface. For other service, the method is similiar with the HTTP service. For other ports, replace 3389 with the port you want to open. Recreate DOCKER-USER iptables chain in firewalld. Docker does the port-mapping in the PREROUTING chain of the nat table. # Allow something iptables -A INPUT -p tcp -m multiport --dports 22,80,443 -j . Method 1 Open Docker Swarm Ports Using FirewallD. Edit ' /etc/rc.local ' file add following entry to restore iptable rules after every reboot. $ iptables -I DOCKER -i ext_if ! Docker iptables rules are causing a problem. DOCKER-USER Install iptables-docker Local install (sh) NOTE this kind of install use a static file (src/iptables-docker.sh). For example, to restrict external access such that only source IP 8.8.8.8 . Without IP . Ignore any warnings firewall-cmd --permanent --direct --remove-chain ipv4 filter DOCKER-USER -i docker0 -p tcp -m tcp --dport 8080 -j DNAT --to-destination 172.17..2:80 By default, all external source IPs are allowed to connect to the Docker host. # iptables-save > /root/iptable_rules. # Delete old entries if any iptables -F INPUT iptables -F DOCKER-USER iptables -F OUTPUT # Set firewall iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT # Allow established connections iptables -A INPUT -i lo -j ACCEPT # Allow localhost communication iptables -A OUTPUT -o lo -j ACCEPT # Allow output to the internet from . Internally Docker is using iptables to forward connections to the docker host on port 8080 to the service listening on port 80 on the container. If you want to change that behavior to only expose ports on an internal IP address, you can use the --ip option to specify a different IP address. Docker's forward rules permit all external source IPs by default. 3. But FirewallD is also available on other Linux distributions, including Ubuntu 16.04. Requests from the IP range Docker uses are likely getting blocked. It's pretty straightforward to create this new network: $ docker network create \ -o com.docker.network.bridge.name=user0 \ --subnet=172.20../16 \ user However, setting --ip only changes the default, it does not restrict services to that IP. I'm using Ubuntu 19.10, but this should work on other Linux distributions. By default, the Docker daemon will expose ports on the 0.0.0.0 address, i.e. Save and close the file. You put your iptables -A INPUT -j DROP at the end and then you are . iptables -I DOCKER-USER -o eth0 -d 192.168..69 -p tcp --sport 8080 -j RETURN The above commands add two rules stating that any forwarded tcp packets either incoming or outgoing from. For UFW, that would be: sudo ufw allow from 172.18../24 To allow specific traffic you have to edit manually this file with your own rules: To allow only a specific IP or network to access the containers, insert a negated rule at the top of the DOCKER filter chain. Hi, The Docker networking documentation show's how to easily restrict external container access to a single IP using Iptables. To allow only a specific IP or network to access the containers, insert a negated rule at the top of the DOCKER-USER filter chain. The type of network a container uses, whether it is a bridge, an overlay, a macvlan network, or a custom network plugin, is transparent from within the container.From the container's point of view, it has a network interface with an IP address, a gateway, a routing table, DNS services, and other networking details (assuming the . sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT This post focuses on the other technique Docker uses, iptables, which can also be used to forward requests from a port in the host network namespace to an IP address and port residing in another network namespace. Therefore I use the following iptables entry for the ip of my external interface (ext_if): Method 2 Opening Docker Swarm Ports Using FirewallD. DOCKER-USER Install iptables-docker The first step is to clone this repository Local install (sh) NOTE this kind of install use a static file (src/iptables-docker.sh). I'm running OpenMediaVault 5.x with Docker on the host machine and was able to access the OpenMediaVault WebGUI through 192.168.1.21:80. For example, the following rule restricts external access from all IP addresses except 192.168.1.1: You may choose which ones to be used. . By default, all external source IPs are allowed to connect to the Docker daemon. I have a server that runs docker containers. This rule says: allow new and established inbound traffic from the 172.16../26 network to the port 443 on the tcp protocol. FirewallD is the default firewall application on CentOS 7, but on a new CentOS 7 server, it is disabled out of the box. User connection attempt is filtered based on INPUT configurations, etc Traffic forwarding then happens as usual based on the docker-added FORWARD rules mentioned this issue To allow public access to port 8080. To enable access to an HTTP web server, use the following command. By default only ssh access to local machine is allowd. Filed Under: Before starting, verify its status: systemctl status firewalld To allow specific traffic you have to edit manually this file with your own rules: The fix is very simpleopen this port range in your firewall. For example: sudo iptables -A INPUT -p tcp --dport ssh -j ACCEPT The ssh in the command translates to port number 22, which the protocol uses by default. Why would you want to allow all the ports in your iptables configuration as it means then nearly that you don't have the iptables enabled at all!?!? chain_name is either INPUT, OUTPUT, or FORWARD. By default, Docker uses the 172.18../16 block to allocate container IP addresses. For example, the following rule restricts external access to all IP addresses except 192.168.1.1: Note: This post only works on Linux. Estimated reading time: 4 minutes. It turns out the examples rules are not good for a single Docker host to expose host ports. Even worse, the nat entries used for that seem to "bypass" the protection rules of firewalld (apart from other problems with firewalld and Docker). # iptables-restore < /root/iptable_rules. -s 8.8.8.8 -j DROP Indeed, adding a rule at the top of the DOCKER table is a good idea. From the process path in the "iptables" part, the packet will also pass the FORWARD chains. If you would like to disable up and running iptables, you can do that running the following commands: iptables -F iptables -X iptables -t nat -F iptables -t nat -X iptables -t mangle -F Improve this answer. How to allow specific ports for docker using iptables --> dport uses port within the container Ask Question 0 In the first step I want to block all incoming traffic to the docker containers running on my server. We add the second rule in FORWARD chain to allow forwarding the packets to port 8080 of 192.168.1.2. 2. To avoid conflict with a container that needs to use port 443 and 80, I switched the OMV WebGUI port to 81. To access the original destination, you can use -m conntrack --ctorigdstport.