What ports does RabbitMQ use?

PORT 4369: Erlang makes use of a Port Mapper Daemon (epmd) for resolution of node names in a cluster. Nodes must be able to reach each other and the port mapper daemon for clustering to work.

PORT 35197 set by inet_dist_listen_min/max Firewalls must permit traffic in this range to pass between clustered nodes

RabbitMQ Management console:

• PORT 15672 for RabbitMQ version 3.x
• PORT 55672 for RabbitMQ pre 3.x

PORT 5672 RabbitMQ main port.

For a cluster of nodes, they must be open to each other on 35197, 4369 and 5672.

For any servers that want to use the message queue, only 5672 is required.

What ports is RabbitMQ using?

Default: 5672, the manual has the answer. It's defined in the RABBITMQ_NODE_PORT variable.

https://www.rabbitmq.com/configure.html#define-environment-variables

The number might be differently if changed by someone in the rabbitmq configuration file:

vi /etc/rabbitmq/rabbitmq-env.conf

Ask the nmap if it can see it:

sudo nmap -p 1-65535 localhost

Starting Nmap 5.51 ( http://nmap.org ) at 2014-09-19 13:50 EDT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00041s latency).
PORT      STATE         SERVICE
443/tcp   open          https
5672/tcp  open          amqp
15672/tcp open  unknown
35102/tcp open  unknown
59440/tcp open  unknown

Oh look, 5672, and 15672

Ask netstat if it can see it:

netstat -lntu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address        State
tcp        0      0 0.0.0.0:15672               0.0.0.0:*              LISTEN
tcp        0      0 0.0.0.0:55672               0.0.0.0:*              LISTEN
tcp        0      0 :::5672                     :::*                   LISTEN

Oh look 5672.

lsof to see ports:

eric@dev ~$ sudo lsof -i | grep beam
beam.smp  21216    rabbitmq   17u  IPv4 33148214      0t0  TCP *:55672 (LISTEN)
beam.smp  21216    rabbitmq   18u  IPv4 33148219      0t0  TCP *:15672 (LISTEN)

use nmap from a different machine, find out if 5672 is open:

sudo nmap -p 5672 10.0.1.71
Starting Nmap 5.51 ( http://nmap.org ) at 2014-09-19 13:19 EDT
Nmap scan report for 10.0.1.71
Host is up (0.00011s latency).
PORT     STATE SERVICE
5672/tcp open  amqp
MAC Address: 0A:40:0E:8C:75:6C (Unknown)    
Nmap done: 1 IP address (1 host up) scanned in 0.13 seconds

Try to connect to a port manually with telnet, 5671 is CLOSED:

telnet localhost 5671
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused

Try to connect to a port manually with telnet, 5672 is OPEN:

telnet localhost 5672
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

Check your firewall:

sudo cat /etc/sysconfig/iptables  

It should tell you what ports are made open:

-A INPUT -p tcp -m tcp --dport 5672 -j ACCEPT

Reapply your firewall:

sudo service iptables restart
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
iptables: Applying firewall rules:                         [  OK  ]