Turn Off Unnecessary Services

What Are Services?

Computer "services" generally refers to programs that listen for and respond to network traffic. Other services allow direct access to your computer. Examples include:

• Web servers, file servers, FTP servers, email and proxy servers
• Remote access programs such as Remote Desktop
• Open ports
• Guest accounts and other open points of access to your computer and your files
• Recursive domain name servers (DNS)

In general, services are necessary only if there is a clear university business or educational need for them and they are appropriate given your role at the university. 

Why Turn Off Unnecessary Services?

• Many cybersecurity breaches are a result of people taking advantage of security holes or problems with these services.
• The more services that are running on your computer, the more opportunities there are for others to use them, break into or take control of your computer through them.

Which Services Should Be Turned Off?

Services must be disabled if they:

• Introduce a security risk.
• Interfere with other university resources or the network.
• Create an excessive burden on campus infrastructure or resources.

Services creating any of the harmful conditions above are subject to blocking or disconnection from the campus network per ITS Procedures for Blocking Network Access.

Avoid Open Recursive Domain Name Servers (DNS)

A specific example of a service that can cause problems and should be turned off is open recursive DNS, a type of server that allows certain requests to be made from outside the normal network. Attackers can take advantage of this service to overload a system with unnecessary traffic, which can make it stop working properly. This is called an “amplification attack,” a type of cyberattack that aims to disrupt a target's online services. The DNS servers at UC Santa Cruz have been used in this kind of attack before.

To prevent these attacks from happening and protect UCSC's servers, systems administrators must disable open recursive DNS servers. Any open recursive server identified on the campus network will be considered a security risk subject to immediate disconnection per ITS Procedures for Blocking Network Access.

The ITS Network Operations Center operates a set of highly reliable, fast, and secure recursive DNS servers, and we recommend all campus users make use of these systems rather than local, departmental versions of the same. These servers are:

If you believe you need to run a non-open, recursive DNS service and cannot use the servers ITS offers, please be sure to follow the advice given on the Cybersecurity and Infrastructure Security Agency’s DNS Amplification Attacks page. 

Recommendations for Mobile Devices and Laptops

• Disable Bluetooth, wireless and IrDA (infrared) when you're not actively using them.
• Periodically go through your device's list of known wireless networks and delete ones no longer needed (usually found under network, wireless, or airport settings).
• Set your device to "ask" before connecting to unknown wireless networks.
• Disable or remove applications (apps) and plug-ins that you don't actively use.

Get Help

• Contact the ITS Support Center if you have any questions about DNS requirements or if you would like your computer configured to meet the requirements outlined on this page. 
• Contact the ITS Support Center or your ITS Divisional Liaison if you have questions about whether specific services are necessary to your role at the university.

Back to “How to Stay Secure”