BRIDGE and Firewalls


TeacherBridge uses Java WebStart to download and run the Full Editor client software. The interactive features of the system require that the client be allowed to open a network connection from the user's machine to the TeacherBridge server on the VT Center for HCI's network. This can present a problem, as many organization's networks are protected by a "firewall" that sits between the local network and the Internet. In this context, firewalls typically block connections from machines behind the firewall to arbitrary machines on the Internet. In order to use the Full Editor, you may need to ask your network administrator to allow connections to the TeacherBridge server. This can usually be done in such a way that only connections to the specific host and port* used by TeacherBridge are allowed, and will therefore not compromise network security.

In addition to firewall systems designed to protect an entire network, your computer may have "personal firewall" software installed that blocks unrecognized incoming and outgoing connections. Personal firewalls are intended to prevent malicious software from infecting your machine through the network and, conversely, to prevent viruses or worms that find their way onto your machine from using the network to infect others. It may also be necessary to tell your personal firewall to allow outbound connections to the TeacherBridge server.

*A "port" is a number that identifies a specific piece of server software running on given computer. For example, the same server machine can run a web server, an email server, and a TeacherBridge server by assigning them to different ports. Firewalls typically filter connections based on both host name and port so that, for example, connections to arbitrary external web servers are allowed.

To allow TeacherBridge to connect behind the system firewall:


GCPS Firewall

The Web Editor should work behind the GCPS firewall. To run the Full Editor, simply download Java WebStart or the latest Java on your computer. In order to connect to the Internet behind the GCPS firewall, your computer will need to be registered with your network administrator and given an IP address.

MCPS Firewall

The Web Editor should work behind the MCPS firewall. To run the Full Editor, simply download Java WebStart or the latest Java on your computer. You might need to contact your technical support staff to install WebStart on an MCPS computer. It is already installed on many. In order to access the Internet from within MCPS, you need to apply network proxy settings to your computers network configuration.
For MCPS, the proxy IP is: 198.82.201.19 and the Port is: 8002. Make sure Webstart is set to use web proxy by opening up Webstart application from the desktop icon or program menu and selecting the option.

Other School System Firewalls

Several other school systems have kindly opened up port 23456 to our TeacherBridge server. It is not extremely difficult for a network administrator to do this, and it is relatively safe, especially if they limit the connection specifically to the TeacherBridge host at IP 128.173.54.22 (teacherbridge.cs.vt.edu). Ask your network administrator or technical staff to do this if the web editor is not sufficient to your needs. Note that the much of the functionality can be achieved through the web editor (any web browser connected to the Internet). Outside of your school or corporate firewall, this should be less of an issue, and web content will still be available and filtered as is any other Internet content behind your school firewall regardless of this port setting. Please let us know if you or your technical staff has any questions or would like support.

To allow TeacherBridge to connect through the Windows personal Firewall, try the following:



/public/support/network admin Login | Web Editor | Full Editor
Last modified 3/29/05 11:57 AM by dunlapd (history)
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