Gazebo node cannot see Gazebo Topic, need help understanding why

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I used this tutorial to get me going http://gazebosim.org/tutorials?tut=gu....

It gave me enough information to create a gazebo model plugin, and a standalone gazebo node that would use a gazebo transport node to publish commands to a Gazebo topic.

My problem is that my gazebo model plugin is unable to see when a message is sent to the gazebo topic ("/topic/a") even though I have a gazebo subscriber callback function for "/topic/a". To confirm that I was publishing and subscribing to the gazebo topic I opened a terminal and used the command

"gz topic -i /topic/a"

The response was

Type: gazebo.msgs.Vector3d

Publishers:
    Same IP:43457

Subscribers:
    Same IP:45557

They had the same IP but different ports. Is that normal? How do I get both gazebo nodes to look at the same Gazebo topic?

My code for my standalone is below

#include <gazebo/gazebo_client.hh>
#include <gazebo/common/common.hh>
#include <gazebo/gazebo_config.h>
#include <gazebo/physics/physics.hh>
#include <gazebo/transport/transport.hh>
#include <gazebo/msgs/msgs.hh>


void callback_from_gazebo(ConstVector3dPtr &_msg) {   std::cout << "Callback received () \n"; }


int main(int _argc, char **_argv) {     std::cout << "Gazebo Initialization \n";
    gazebo::transport::PublisherPtr pub1,pub2;
    gazebo::transport::SubscriberPtr sub1;

    gazebo::client::setup(_argc, _argv);

    gazebo::transport::init();
    gazebo::transport::run();
    gazebo::transport::NodePtr node(new gazebo::transport::Node());
    node->Init("default");
    std::cout << "End Gazebo Initialization \n";

    std::cout << "Define Gazebo Publishers and Subscribers \n";
    pub1 = node->Advertise<gazebo::msgs::Vector3d>("/topic/a");
    pub2 = node->Advertise<gazebo::msgs::WorldControl>("/gazebo/torqueprofile/world_control");
    sub1 = node->Subscribe("/topic/b", callback_from_gazebo);

    std::cout << "Waiting for connection\n";
    pub1->WaitForConnection();
    pub2->WaitForConnection();
    std::cout << "Connections confirmed\n";

    while(1)
    {
        gazebo::msgs::Vector3d cmd;
        cmd.set_x(1);
        cmd.set_y(2);
        cmd.set_z(3);
        pub1->WaitForConnection();
        pub1->Publish(cmd);

        gazebo::msgs::WorldControl world_msg;
        world_msg.set_step(true);
        pub2->Publish(world_msg);

        gazebo::common::Time::MSleep(1000);
    }

    gazebo::transport::fini();
    gazebo::client::shutdown();
    return 0; }

My code for my plugin is below

#include <boost/bind.hpp>
#include <gazebo/transport/transport.hh>
#include <gazebo/msgs/msgs.hh>
#include <gazebo/physics/physics.hh>
#include <gazebo/common/common.hh>
#include <gazebo/math/Angle.hh>
#include <gazebo/gazebo_client.hh>
#include <gazebo/gazebo_config.h>
#include <stdio.h>
#include <fstream>


namespace gazebo
{
  /// \brief A plugin to control two cubes strictly in Gazebo
  class gazebo_simple_plugin : public ModelPlugin
  {
    /// \brief Constructor
    public: gazebo_simple_plugin() 
    {
    }


    public: virtual void Load(physics::ModelPtr _model, sdf::ElementPtr _sdf)
    {
        model = _model;

        if (model->GetJointCount() == 0)
        {
            std::cerr << "\n no joints \n";
            return;
        }
        else
            std::cerr << "\n joints are there \n";

        //set joint handle to joints in the _model
        joint1 = model->GetJoints()[0]; 

        // Create the Gazebo node
        node = transport::NodePtr(new transport::Node());
        node->Init(this->model->GetWorld()->GetName());

        pub1 = node->Advertise<gazebo::msgs::Vector3d>("/topic/b");
        sub1 = node->Subscribe("/topic/a", &gazebo_simple_plugin::callback_from_standalone, this);

        //Listen to the update event. This event is broadcast every
        updateConnection = event::Events::ConnectWorldUpdateBegin(boost::bind(&gazebo_simple_plugin::OnUpdate, this, _1));

    }


    private: void callback_from_standalone(ConstVector3dPtr &_msg)
    {
      cmd=(_msg->x());
      printf("cmd received ...