To operate properly, Rancher requires a number of ports to be open on Rancher nodes and on downstream Kubernetes cluster nodes.

Rancher Nodes

The following table lists the ports that need to be open to and from nodes that are running the Rancher server.

The port requirements differ based on the Rancher server architecture.

Notes:

  • Rancher nodes may also require additional outbound access for any external authentication provider which is configured (LDAP for example).
  • Kubernetes recommends TCP 30000-32767 for node port services.
  • For firewalls, traffic may need to be enabled within the cluster and pod CIDR.

Ports for Rancher Server Nodes on K3s

The K3s server needs port 6443 to be accessible by the nodes.

The nodes need to be able to reach other nodes over UDP port 8472 when Flannel VXLAN is used. The node should not listen on any other port. K3s uses reverse tunneling such that the nodes make outbound connections to the server and all kubelet traffic runs through that tunnel. However, if you do not use Flannel and provide your own custom CNI, then port 8472 is not needed by K3s.

If you wish to utilize the metrics server, you will need to open port 10250 on each node.

Important: The VXLAN port on nodes should not be exposed to the world as it opens up your cluster network to be accessed by anyone. Run your nodes behind a firewall/security group that disables access to port 8472.

The following tables break down the port requirements for inbound and outbound traffic:

Inbound Rules for Rancher Server Nodes
Protocol Port Source Description
TCP 80 Load balancer/proxy that does external SSL termination Rancher UI/API when external SSL termination is used
TCP 443
  • server nodes
  • agent nodes
  • hosted/imported Kubernetes
  • any source that needs to be able to use the Rancher UI or API
Rancher agent, Rancher UI/API, kubectl
TCP 6443 K3s server nodes Kubernetes API
UDP 8472 K3s server and agent nodes Required only for Flannel VXLAN.
TCP 10250 K3s server and agent nodes kubelet
Outbound Rules for Rancher Nodes
Protocol Port Destination Description
TCP 22 Any node IP from a node created using Node Driver SSH provisioning of nodes using Node Driver
TCP 443 git.rancher.io Rancher catalog
TCP 2376 Any node IP from a node created using Node driver Docker daemon TLS port used by Docker Machine
TCP 6443 Hosted/Imported Kubernetes API Kubernetes API server

Ports for Rancher Server Nodes on RKE

Typically Rancher is installed on three RKE nodes that all have the etcd, control plane and worker roles.

The following tables break down the port requirements for traffic between the Rancher nodes:

Rules for traffic between Rancher nodes
Protocol Port Description
TCP 443 Rancher agents
TCP 2379 etcd client requests
TCP 2380 etcd peer communication
TCP 6443 Kubernetes apiserver
UDP 8472 Canal/Flannel VXLAN overlay networking
TCP 9099 Canal/Flannel livenessProbe/readinessProbe
TCP 10250 kubelet
TCP 10254 Ingress controller livenessProbe/readinessProbe

The following tables break down the port requirements for inbound and outbound traffic:

Inbound Rules for Rancher Nodes
Protocol Port Source Description
TCP 22 RKE CLI SSH provisioning of node by RKE
TCP 80 Load Balancer/Reverse Proxy HTTP traffic to Rancher UI/API
TCP 443
  • Load Balancer/Reverse Proxy
  • IPs of all cluster nodes and other API/UI clients
HTTPS traffic to Rancher UI/API
TCP 6443 Kubernetes API clients HTTPS traffic to Kubernetes API
Outbound Rules for Rancher Nodes
Protocol Port Destination Description
TCP 443 35.160.43.145,35.167.242.46,52.33.59.17 Rancher catalog (git.rancher.io)
TCP 22 Any node created using a node driver SSH provisioning of node by node driver
TCP 2376 Any node created using a node driver Docker daemon TLS port used by node driver
TCP 6443 Hosted/Imported Kubernetes API Kubernetes API server
TCP Provider dependent Port of the Kubernetes API endpoint in hosted cluster Kubernetes API

Ports for Rancher Server in Docker

The following tables break down the port requirements for Rancher nodes, for inbound and outbound traffic:

Inbound Rules for Rancher Node
Protocol Port Source Description
TCP 80 Load balancer/proxy that does external SSL termination Rancher UI/API when external SSL termination is used
TCP 443
  • hosted/imported Kubernetes
  • any source that needs to be able to use the Rancher UI or API
Rancher agent, Rancher UI/API, kubectl
Outbound Rules for Rancher Node
Protocol Port Source Description
TCP 22 Any node IP from a node created using Node Driver SSH provisioning of nodes using Node Driver
TCP 443 git.rancher.io Rancher catalog
TCP 2376 Any node IP from a node created using a node driver Docker daemon TLS port used by Docker Machine
TCP 6443 Hosted/Imported Kubernetes API Kubernetes API server

Downstream Kubernetes Cluster Nodes

Downstream Kubernetes clusters run your apps and services. This section describes what ports need to be opened on the nodes in downstream clusters so that Rancher can communicate with them.

The port requirements differ depending on how the downstream cluster was launched. Each of the tabs below list the ports that need to be opened for different cluster types.

The following diagram depicts the ports that are opened for each cluster type.

Port Requirements for the Rancher Management Plane

Basic Port Requirements

Tip:

If security isn’t a large concern and you’re okay with opening a few additional ports, you can use the table in Commonly Used Ports as your port reference instead of the comprehensive tables below.

Ports for Rancher Launched Kubernetes Clusters using Node Pools

The following table depicts the port requirements for Rancher Launched Kubernetes with nodes created in an Infrastructure Provider.

Note: The required ports are automatically opened by Rancher during creation of clusters in cloud providers like Amazon EC2 or DigitalOcean.

From / To Rancher Nodes etcd Plane Nodes Control Plane Nodes Worker Plane Nodes External Rancher Load Balancer Internet
Rancher Nodes (1) 22 TCP git.rancher.io
2376 TCP
etcd Plane Nodes 443 TCP (3) 2379 TCP 443 TCP
2380 TCP
6443 TCP
8472 UDP
9099 TCP (4)
Control Plane Nodes 443 TCP (3) 2379 TCP 443 TCP
2380 TCP
6443 TCP
8472 UDP
10250 TCP
9099 TCP (4)
10254 TCP (4)
Worker Plane Nodes 443 TCP (3) 6443 TCP 443 TCP
8472 UDP
9099 TCP (4)
10254 TCP (4)
Kubernetes API Clients 6443 TCP (5)
Workload Clients or Load Balancer 30000-32767 TCP / UDP
(nodeport)
80 TCP (Ingress)
443 TCP (Ingress)
Notes:

1. Nodes running standalone server or Rancher HA deployment.
2. Required to fetch Rancher chart library.
3. Only without external load balancer in front of Rancher.
4. Local traffic to the node itself (not across nodes).
5. Only if Authorized Cluster Endpoints are activated.

Ports for Rancher Launched Kubernetes Clusters using Custom Nodes

The following table depicts the port requirements for Rancher Launched Kubernetes with Custom Nodes.

From / To Rancher Nodes etcd Plane Nodes Control Plane Nodes Worker Plane Nodes External Rancher Load Balancer Internet
Rancher Nodes (1) git.rancher.io
etcd Plane Nodes 443 TCP (3) 2379 TCP 443 TCP
2380 TCP
6443 TCP
8472 UDP
4789 UDP (6)
9099 TCP (4)
Control Plane Nodes 443 TCP (3) 2379 TCP 443 TCP
2380 TCP
6443 TCP
8472 UDP
4789 UDP (6)
10250 TCP
9099 TCP (4)
10254 TCP (4)
Worker Plane Nodes 443 TCP (3) 6443 TCP 443 TCP
8472 UDP
4789 UDP (6)
9099 TCP (4)
10254 TCP (4)
Kubernetes API Clients 6443 TCP (5)
Workload Clients or Load Balancer 30000-32767 TCP / UDP
(nodeport)
80 TCP (Ingress)
443 TCP (Ingress)
Notes:

1. Nodes running standalone server or Rancher HA deployment.
2. Required to fetch Rancher chart library.
3. Only without external load balancer in front of Rancher.
4. Local traffic to the node itself (not across nodes).
5. Only if Authorized Cluster Endpoints are activated.
6. Only if using Overlay mode on Windows cluster.

Ports for Hosted Kubernetes Clusters

The following table depicts the port requirements for hosted clusters.

From / To Rancher Nodes Hosted / Imported Cluster External Rancher Load Balancer Internet
Rancher Nodes (1) Kubernetes API
Endpoint Port (2)
git.rancher.io
8443 TCP
9443 TCP
Hosted / Imported Cluster 443 TCP (4)(5) 443 TCP (5)
Kubernetes API Clients Cluster / Provider Specific (6)
Workload Client Cluster / Provider Specific (7)
Notes:

1. Nodes running standalone server or Rancher HA deployment.
2. Only for hosted clusters.
3. Required to fetch Rancher chart library.
4. Only without external load balancer.
5. From worker nodes.
6. For direct access to the Kubernetes API without Rancher.
7. Usually Ingress backed by infrastructure load balancer and/or nodeport.

Ports for Imported Clusters

The following table depicts the port requirements for imported clusters.

From / To Rancher Nodes Hosted / Imported Cluster External Rancher Load Balancer Internet
Rancher Nodes (1) Kubernetes API
Endpoint Port (2)
git.rancher.io
8443 TCP
9443 TCP
Hosted / Imported Cluster 443 TCP (4)(5) 443 TCP (5)
Kubernetes API Clients Cluster / Provider Specific (6)
Workload Client Cluster / Provider Specific (7)
Notes:

1. Nodes running standalone server or Rancher HA deployment.
2. Only for hosted clusters.
3. Required to fetch Rancher chart library.
4. Only without external load balancer.
5. From worker nodes.
6. For direct access to the Kubernetes API without Rancher.
7. Usually Ingress backed by infrastructure load balancer and/or nodeport.

Other Port Considerations

Commonly Used Ports

These ports are typically opened on your Kubernetes nodes, regardless of what type of cluster it is.

Protocol Port Description
TCP 22 Node driver SSH provisioning
TCP 179 Calico BGP Port
TCP 2376 Node driver Docker daemon TLS port
TCP 2379 etcd client requests
TCP 2380 etcd peer communication
UDP 8472 Canal/Flannel VXLAN overlay networking
UDP 4789 Flannel VXLAN overlay networking on Windows cluster
TCP 8443 Rancher webhook
TCP 9099 Canal/Flannel livenessProbe/readinessProbe
TCP 9100 Default port required by Monitoring to scrape metrics from Linux node-exporters
TCP 9443 Rancher webhook
TCP 9796 Default port required by Monitoring to scrape metrics from Windows node-exporters
TCP 6783 Weave Port
UDP 6783-6784 Weave UDP Ports
TCP 10250 kubelet API
TCP 10254 Ingress controller livenessProbe/readinessProbe
TCP/UDP 30000-
32767
NodePort port range

Local Node Traffic

Ports marked as local traffic (i.e., 9099 TCP) in the above requirements are used for Kubernetes healthchecks (livenessProbe andreadinessProbe). These healthchecks are executed on the node itself. In most cloud environments, this local traffic is allowed by default.

However, this traffic may be blocked when:

  • You have applied strict host firewall policies on the node.
  • You are using nodes that have multiple interfaces (multihomed).

In these cases, you have to explicitly allow this traffic in your host firewall, or in case of public/private cloud hosted machines (i.e. AWS or OpenStack), in your security group configuration. Keep in mind that when using a security group as source or destination in your security group, explicitly opening ports only applies to the private interface of the nodes / instances.

Rancher AWS EC2 Security Group

When using the AWS EC2 node driver to provision cluster nodes in Rancher, you can choose to let Rancher create a security group called rancher-nodes. The following rules are automatically added to this security group.

Type Protocol Port Range Source/Destination Rule Type
SSH TCP 22 0.0.0.0/0 Inbound
HTTP TCP 80 0.0.0.0/0 Inbound
Custom TCP Rule TCP 443 0.0.0.0/0 Inbound
Custom TCP Rule TCP 2376 0.0.0.0/0 Inbound
Custom TCP Rule TCP 2379-2380 sg-xxx (rancher-nodes) Inbound
Custom UDP Rule UDP 4789 sg-xxx (rancher-nodes) Inbound
Custom TCP Rule TCP 6443 0.0.0.0/0 Inbound
Custom UDP Rule UDP 8472 sg-xxx (rancher-nodes) Inbound
Custom TCP Rule TCP 10250-10252 sg-xxx (rancher-nodes) Inbound
Custom TCP Rule TCP 10256 sg-xxx (rancher-nodes) Inbound
Custom TCP Rule TCP 30000-32767 0.0.0.0/0 Inbound
Custom UDP Rule UDP 30000-32767 0.0.0.0/0 Inbound
All traffic All All 0.0.0.0/0 Outbound

Opening SUSE Linux Ports

SUSE Linux may have a firewall that blocks all ports by default. To open the ports needed for adding the host to a custom cluster,

  1. SSH into the instance.
  2. Edit /etc/sysconfig/SuSEfirewall2 and open the required ports. In this example, ports 9796 and 10250 are also opened for monitoring: FW_SERVICES_EXT_TCP="22 80 443 2376 2379 2380 6443 9099 9796 10250 10254 30000:32767" FW_SERVICES_EXT_UDP="8472 30000:32767" FW_ROUTE=yes
  3. Restart the firewall with the new ports: SuSEfirewall2

Result: The node has the open ports required to be added to a custom cluster.