NAC - Frequently Asked Questions

Why do I need to register my computer?
The NAC system was put in place due to an overwhelming number of problems on the Residential networks due to computer viruses. By registering each computer and verifying its owner, ITS and Student Computer Services can do a much better job of keeping the residential networks free of viruses and are able to respond faster to problems when they do occur. In addition, by keeping ‘at risk’ computers off of the residential networks, your registered computer is protected from the viruses spread by infected computers.
My computer did not pass the requirements. What do I do?
Computers that do not meet the requirements will have access to the websites they need to update their computer or anti-virus software.  To update your operating system, run the Windows or Apple update program.  The easiest way to update your anti-virus software is to trigger an update from within the anti-virus program itself (through the icon on your taskbar or programs menu).  If you encounter difficulties, contact Student Computer Services for assistance.
Do I have to register if I live off campus or am abroad?
No, you only have to register if you are using the Colby wired or wireless network in the on campus residence halls.
How does a guest login?
Users who do not have a Colby login can login as a guest by clicking on the guest login instead of registered user. Guest logins expire after 6 hours and do not have access to privileged campus resources.
What is required to pass NAC registration?
A valid Colby login (same as e-mail login/account), an up-to-date (patched) computer operating system and up-to-date anti-virus software installed and running.  If your computer does not have anti-virus software, Colby registered users can download Sophos anti-virus and non-Colby users can download a free anti-virus client through the NAC registration system.  If you are using an anti-virus package that is not recognized by the NAC system, you will need to install one of the many programs that are supported.
When do I need to re-register?
Registrations automatically expire when the computer or registered device is not ‘heard’ from in 30 consecutive days.  This expiration is set to ensure users’ privacy (and ensure that a computer that has left the Colby network is verified as being up-to-date.
Once my computer is registered, can Colby ITS see everything I do?
Absolutely not – The system will be operated in accord with the rights to privacy that members of the Colby community are assured under the Code of Ethics for Information Technology at Colby College.  As in the past, there is no monitoring of individual network use.  The system cannot track anything that you do on your computer or on the network.
What is the Persistent Agent, or CSA?  (Vista, WindowsXP/2000 only)
The persistent agent, or CSA, required to be installed by Vista, Windows XP and Windows 2000 users is a small process that must remain installed and running as long as the computer is on the Colby network.  The agent does not monitor system use or activity, and only responds to policy requests from the NAC central server.  Those policy requests are only concerned with Windows update settings and Anti-Virus software.  If a user leaves Colby, they are free to uninstall the agent (using add/remove programs), but will be required to re-install it when they register their computer upon their return to campus.
Is Linux supported?
Linux is supported, but requires that you manually download and execute the CSA script.  If you have trouble getting through the registration process, contact Student Computer Services at x4224.
I have a game console, Tivo, or other device that requires network access. What do I do?
You can register your handheld/gaming device by going to
This link is only accessible from on campus. You will need to contact Student Computer Services (x4224) in order to register any networked device that does not have a web browser.

If I leave Colby and come back, do I need to re-register?
If your computer is away from the network for more than 30 days, you will need to re-register the computer.  This process will be automatically triggered when you connect your computer to the network upon your return.

What will the NAC Persistent Agent do when I leave Colby?
The agent will do nothing (off-campus agent traffic is prohibited), but it will continue to run.  If you wish to uninstall it from your computer, you can do so via the Add/Remove Programs option within the Control Panel.  You will need to re-install the agent during registration if and when you return to Campus.
What is the problem with personal hubs/switches/routers and wireless access points?
Networking devices placed in-between your computer and the Colby network create confusion for the network access control (NAC) system that is in place on the Residence Hall networks. This confusion will prevent your computers network connection from working properly, or working at all.  If necessary, wired personal hubs/switches are permitted (please see associated document on hubs and switches linked at top).  Personal routers or access points are prohibited in the residence halls.  Users should register their computer over a wired network port (without the intermediary device) before contacting Student Computer Services (SCS) for assistance with a networking device.
What kind of device do I have?
An ethernet hub or switch is an unmanaged device that allows you to connect multiple computers to a single wall jack (or WAN link). The device does not have management functions or an IP address. These devices should have the words hub or switch printed somewhere on them.

A router is a managed device which has its own Internet address that can perform network address translation (NAT) as well as other networking functions to a personal wired network. Colby students should have no need to operate a router because Colby does not limit the number of IP addressed computers a user can have.

A wireless access point combines the functions of a hub or router with a wireless signal so that it can accept connections from both wired and wireless computers.

I have a hub or switch. What should I do?
Users of personal hubs or switches should register any and all computers over a directly-connected network port before connecting through the hub or switch. Once computers are registered on the network, they can then connect through a hub or switch without problems. Users connecting through hubs and switches need to realize that any computer connected through the hub or switch could possibly interrupt the connection for all the other computers sharing the connection contact SCS for a full explanation of these limitations.  For more information on hub and switch operation, consult the page linked at top or contact SCS.

I have a router. What should I do?
Personal routers and wireless access points are prohibited in the residence halls.  These devices will not function properly (client computers will have no Internet access) because the device is not registered in the NAC system.  ITS will disconnect any operating routers or access points upon discovery.

I have a wireless access point. What should I do?
Personal routers and wireless access points are prohibited in the residence halls.  These devices will not function properly (client computers will have no Internet access) because the device is not registered in the NAC system.  ITS will disconnect any operating routers or access points upon discovery.

I registered my computer while I was connected through a hub or switch and now I have no Internet access (I keep getting the registration page).
This is most likely because there is an unregistered device connected to the hub or switch.  Connect your computer(s) directly to a network port (do not use the switch/hub), complete your registration if necessary, and then re-introduce the computer(s) to the switch or hub one at a time.
Why are personal access points/routers prohibited?
Because the Colby Wireless network spans all of the residence halls, there is no technical need for students to operate their own access points or routers.  Furthermore, the use of additional wireless access points introduces increased competition for radio frequency spectrum, causing interference and performance problems for the Colby Wireless network and the clients using it.