title: Client cannot Connect to Remote Rabbitmq Server
body: <p>I'm running a Rabbitmq server on Machine A where tasks can be put into the message queue. Machine B is supposed to connect to the AMQP server on Machine A and do the tasks. My <code>rabbitmq-env.conf</code> settings are:</p>
  
  <pre><code>NODE_IP_ADDRESS=
  NODE_PORT=5672
  </code></pre>
  
  <p>I can connect to the server on Machine A locally. When run <code>nmap -p 5672 localhost</code>. It shows:</p>
  
  <pre><code>Nmap scan report for localhost (127.0.0.1)
  Host is up (0.000094s latency).
  PORT     STATE SERVICE
  5672/tcp open  amqp
  </code></pre>
  
  <p>But on Machine B, when running Celery worker, it says: </p>
  
  <pre><code>consumer: Cannot connect to amqp://myuser:**@{server_IP}:5672/myvhost: timed out.
  </code></pre>
  
  <p><code>nmap -p 5672 {server_IP}</code> shows:</p>
  
  <pre><code>Host is up (0.0013s latency).
  PORT     STATE    SERVICE
  5672/tcp filtered amqp
  </code></pre>
  
  <p>I can be sure that my Broker url setting in Celery is correct and I'm not using a guest account for rabbitmq.</p>
  
  <p>My server status shows:</p>
  
  <pre><code>[{pid,2580},
   {running_applications,[{rabbit,"RabbitMQ","3.2.4"},
                          {os_mon,"CPO  CXC 138 46","2.2.14"},
                          {xmerl,"XML parser","1.3.5"},
                          {mnesia,"MNESIA  CXC 138 12","4.11"},
                          {sasl,"SASL  CXC 138 11","2.3.4"},
                          {stdlib,"ERTS  CXC 138 10","1.19.4"},
                          {kernel,"ERTS  CXC 138 10","2.16.4"}]},
   {os,{unix,linux}},
   {erlang_version,"Erlang R16B03 (erts-5.10.4) [source] [64-bit] [async-threads:30] [kernel-poll:true]\n"},
   {memory,[{total,40419400},
            {connection_procs,205272},
            {queue_procs,60240},
            {plugins,0},
            {other_proc,13473800},
            {mnesia,75128},
            {mgmt_db,0},
            {msg_index,30440},
            {other_ets,748888},
            {binary,5264592},
            {code,16522377},
            {atom,594537},
            {other_system,3444126}]},
   {vm_memory_high_watermark,0.4},
   {vm_memory_limit,1552420044},
   {disk_free_limit,50000000},
   {disk_free,6313250816},
   {file_descriptors,[{total_limit,924},
                      {total_used,7},
                      {sockets_limit,829},
                      {sockets_used,3}]},
   {processes,[{limit,1048576},{used,153}]},
   {run_queue,0},
   {uptime,8}]
  ...done.
  </code></pre>
  
  <p>Both Machine A and Machine B are Google Compute Engine VMs under the same project. Any input will be greatly appreciated. Thanks a lot.</p>