Troubleshooting Various Problems

• General Connectivity Problems

• Hosting and Running Servers

• Using Multiple Computers

• Security Issues

General Connectivity Problems

As you continue to use your service, you may experience problems or slowness with your network connection. If your network connection stops working entirely, please use the troubleshooting sections in the online manual: Appendix A (Windows) and Appendix B (MAC) to try to isolate and work through the problem. If this does not resolve your problem, you can call the Xavier Help Desk at (513) 745-4863 for further assistance.

If some services work and other services do not work, try to determine what the services that are not working have in common. If you can get to Xavier web sites like the Xavier web server and Xavier's Blackboard web site, then your connection works on campus. If your can get to OARnet's web site, then our Internet connection is working as well (OARnet is Xavier's Internet Service Provider). Beyond that, there may be a temporary outage to a site. Please try again at a different time and if it continues not to work over several days, please contact the student help desk for further assistance.

If you are installing new software on your system and it works on campus but not off campus, it may be having a problem with Xavier's firewall. Some software, such as remote control software, may require your system to act as a server. If so, you will need to register your system to have the firewall modified to support this service. Please note that this will not help improve the speed of your application - if the program works at all, the firewall is not the problem (for slowness, see below).

Some network software may work fine when connecting to a machine on campus, but may work very slowly when connected to a machine off campus. Xavier's Internet connection is much smaller that our campus network. When many people try to use it at once, there can be congestion and some applications may not work as well. Try using the application at a different time of day (midnight - 6 am, Monday-Saturday, are the most available times). If your performance improves, then that was your problem. If your performance does not improve, please contact the Student Help Desk at (513) 745-4863 to be referred to the network engineer for further assistance (please note that some non-academic applications receive a lower priority than other applications and may be slower at most, or even all, times).

Xavier's Firewall and Hosting Servers within the ResNet

Xavier has installed a firewall for the campus network to provide some protection against the repeated waves (and any future waves) of attempts from the Internet to break into systems on campus. The firewall is configured to block any attempt to directly contact your system from the Internet (though all connections from your system to the Internet are allowed).

If you wish to configure your system to act as a server for the Internet, you will need to register that system. All servers will be subject to the terms of Xavier's Policy for Responsible Use (including that which bars use of University resources for financial gain or commercial purposes). Systems registered as servers will be required to be kept up to date with the latest security patches to keep them from being vulnerable to compromise. Servers that are compromised (or are shown to be vulnerable to compromise as part of a network security audit) are subject to removal from the network until they are demonstrated to be secure.

Using Multiple Computers on a Single Wall Jack

Xavier provides one jack per person in network-connected residences. Multiple computers can be used on this jack under the following conditions:

• Unauthorized, open wireless devices are not permitted to maintain security.  Periodically, buildings on campus are scanned for unauthorized wireless networks.  If you are found operating an open wireless access point, your network connection will be terminated.  If you have wireless needs or concerns, please contact the Help Desk at x4863 and ask to be referred to the network engineer.
• The student must buy and maintain a UTP Ethernet hub or switch to allow the devices to share the single port.  We recommend Linksys products (a Cisco brand), as they have been used successfully in the past.

Please note that while we strive to make this environment work, Xavier cannot guarantee that all hubs or switches will function on our network.

Security on the Xavier Campus Network

Xavier tries to make the Campus Network as secure as possible, while maintaining usability. For security measures, unauthorized and open wireless access points are not permitted.  Xavier uses Virtual LANs or VLANs as a secure means of separating different types of computers. Computers configured with their own IP address (hard-coded) will not work.  To improve performance, Xavier divides the ResNet population into 9 VLANs with 251 addresses per VLAN in the 206.21.160.xxx to 206.21.169.xxx ranges. Assignments to these VLANs are location based. Machines that are in different VLANs may have trouble discovering services on each other.  This is generally because of restrictions within the VLANs, which are designed to prevent viruses and worms from spreading.  For example, ports 135,137,139, and 445 are blocked to prevent the spreading of Windows viruses and worms, however, this also breaks Windows file sharing.  Software that is designed to work over the Internet should work fine, but software designed to work on a LAN may have problems. If you are having trouble accessing other ResNet computers, please contact the Xavier Help Desk at (513) 745-4863 and ask to be referred to the network engineer for more information and further assistance.