Graphic Hub Administrator Guide

Version 3.8 | Published February 06, 2023 ©

Troubleshooting Networks, Virtual Adapters and Session Disconnects

Some network settings can prevent the Graphic Hub applications from finding other running Graphic Hub Terminals on the network. To locate a machine which is running the Graphic Hub Terminal, try pinging that machine. If the host is not reachable across the network, the Graphic Hub Terminal is not reachable either.

It is necessary to run Graphic Hub Terminal in a local network where the settings shown below are identical on every workstation running the terminal application.

IMPORTANT! While the Graphic Hub and/or the Naming Service are running, the server's network adapter status(es) and IP address(es) may NOT be changed.

To Check Network Settings

  1. On the server machine, go to Start > Run > cmd.

  2. In the console, enter ipconfig /all and press ENTER.

  3. Browse to the current connected network adapter.

  4. Check Subnet Mask and Default Gateway.

  5. Repeat steps 1-3 on the client machine, and see that the Subnet Mask and Default Gateway are identical between client and server.

To Solve Network and Firewall Problems

  1. Make sure that the client can broadcast to other clients and to the Graphic Hub Server. This means all firewalls between server and clients need to allow broadcast.

  2. Make sure the following port settings for the Graphic Hub Terminal are open to firewall traffic in between all clients and servers:

    • TCP Port

    • UDP Port

    • Graphic Hub Server Port

  3. Make sure that local firewall applications allow traffic for all Viz products.

Server Unreachable in Dual Network Setup

If installed on a server with two network cards, the Graphic Hub is normally operating on both networks. However, in certain hardware configurations, Graphic Hub versions 2.4.0, 2.4.1 and 2.4.2 may become unavailable or unresponsive on one of the networks. If this is the case, please submit a Support Request, making sure to include all the required information.

Sessions Keep Disconnecting from the Graphic Hub

Symptoms: Viz Engine is reporting disconnections and reconnect attempts on the console when loading data from the Graphic Hub. This may cause some delay when the session was disconnected (as it needs to reconnect first), as the Graphic Hub pings the client periodically and disconnects the session if it cannot reach it for 90 seconds. In addition, it causes load on the Graphic Hub, a sessions are disconnected periodically and log in again.

This can be caused by the client side firewall, different subnets with restrictions in routing or invalid or missing DNS records for the clients.

Client side firewalls may cause issues when the Viz Engine/Artist version is below 3.8.2 or the Graphic Hub version is below 3.0.0, since the communication protocol used was two-way and required the firewall on the client side to be open for the Artist/Engine processes. However, it is not required to disable the firewall completely, just certain ports need to be open for Artist/Engine.

How to Determine Connection Issues

  • You can verify that clients stay connected with GH Manager in the active session view: see Server Information.

  • Have a look at the login times of the sessions and if they disappear after some time (more than 90 seconds).

  • Have a look at the Graphic Hub journal messages with GH Manager: Journal Panel.

  • Filter by Alerts and look for messages with Level 751, 802 and 961 which indicate client connection loss.

How to Fix the Issue

  • Check firewall settings on the client and ensure the required ports are open for Viz Artist and Viz Engine processes.

  • Verify that clients are properly registered at the DNS and reachable from the GH server.