LogStash won't bind to any port

Elastic Stack Logstash
2

OK, I rebooted, and started over.

This time I used this command line to start:

/usr/share/logstash/bin/logstash -f test.conf --path.settings /etc/logstash/

And I got the following in the log:

[2017-12-08T20:01:59,279][INFO ][logstash.modules.scaffold] Initializing module {:module_name=>"fb_apache", :directory=>"/usr/share/logstash/modules/fb_apache/configuration"}
[2017-12-08T20:01:59,379][INFO ][logstash.modules.scaffold] Initializing module {:module_name=>"netflow", :directory=>"/usr/share/logstash/modules/netflow/configuration"}
[2017-12-08T20:02:01,025][INFO ][logstash.pipeline ] Starting pipeline {"id"=>"main", "pipeline.workers"=>1, "pipeline.batch.size"=>125, "pipeline.batch.delay"=>5, "pipeline.max_inflight"=>125}
[2017-12-08T20:02:01,075][INFO ][logstash.pipeline ] Pipeline main started
[2017-12-08T20:02:01,099][INFO ][logstash.inputs.udp ] Starting UDP listener {:address=>"0.0.0.0:9999"}
[2017-12-08T20:02:01,184][INFO ][logstash.inputs.udp ] UDP listener started {:address=>"0.0.0.0:9999", :receive_buffer_bytes=>"106496", :queue_size=>"2000"}
[2017-12-08T20:02:01,473][INFO ][logstash.agent ] Successfully started Logstash API endpoint {:port=>9600}

However, when I send data to port 9999, I still get no output. I DO get output with stdin.

The stdin plugin is now waiting for input:
l;kkjl;kj
{
      "@version" => "1",
          "host" => "server-01",
    "@timestamp" => 2017-12-08T20:03:15.451Z,
    "message" => "l;kkjl;kj"
}

very frustrating...