Docker Swarm Mode Ports

Starting with 1.12 in July 2016, Docker Swarm Mode is a built-in solution with built-in key/value store. Easier to get started, and fewer ports to configure.

Swarm Mode

TCP 3376 # Swarm Manager to/from remote client; docker-machine 
TCP 2376 # Swarm Control Plane (TLS); Docker REST API; NEVER USE it.
TCP 2377 # Swarm Commands; Docker Swarm RPC; cluster management per CLI.
UDP 4789 # Swarm Data; overlay network (VXLAN); container ingress; DATA PATH default
TCP 7946 # Swarm Node-to-node traffic; container network discovery
UDP 7946 # Swarm Node-to-node traffic; container network discovery

Inbound Traffic for Swarm Management

• TCP port 3376 for docker-machine; activate node, certs upload, etc
• TCP port 2377 for cluster management & raft sync communications
• TCP and UDP port 7946 for "control plane" gossip discovery communication between all nodes
• UDP port 4789 for "data plane" VXLAN overlay network traffic
• IP Protocol 50 (ESP) if you plan on using overlay network with the encryption option

AWS Security Group Example (Also @ NACL, Inbound AND Outbound)

AWS Tip: Use Security Groups in AWS's "source" field rather then subnets, so SG's will all dynamically update when new nodes are added.

Inbound to Swarm Managers (superset of worker ports)

Inbound to Swarm Workers

Docker Swarm "Classic" Ports, with Consul

For Docker 1.11 and older. I Used this list from Docker Docs on Swarm Classic, then tested on multiple swarms.

Inbound to Swarm Nodes

• 2375 TCP for swarm manger -> nodes (LOCK PORT DOWN, no auth)
• 7946 TCP/UDP for container network discovery from other swarm nodes
• 4789 UDP container overlay network from other swarm nodes

Inbound to Swarm Managers

• 3375 TCP for spawner -> swarm manager (LOCK PORT DOWN, no auth)

Inbound to Consul

• 8500 TCP for swarm manager/nodes -> consul server (LOCK PORT DOWN, no auth)
• 8300 TCP for consul agent -> consul server
• 8301 TCP/UDP for consul agent -> consul agent
• 8302 TCP/UDP for consul server -> consul server

Swarm Classic Inbound Ports In AWS Security Group Format, with Consul

AWS Tip: You should use Security Groups in AWS's "source" field rather then subnets, so SG's will all dynamically update when new nodes are added.

This is another way to look at the above lists, in a format that makes sense for AWS SG's

• assume AWS inbound from:
  • Internet ELB -> Swarm Managers
  • Swarm Managers -> Swarm Nodes
  • Swarm Managers -> Consul Internal ELB
  • Swarm Nodes -> Consul Internal ELB
  • Consul Internal ELB -> Consul Nodes

ELB Swarm Manager

Swarm Managers

Swarm Nodes

ELB Consul

Consul Nodes