Secure your network
How to secure a 802.11b/g/n wireless home network. Securing a wireless network is very important because if you don't, criminals can not only borrow your Internet connection but also access your files and check up on what you're doing.
Connect to your router via your browser, by inputting something called a Gateway IP Address.
To find your Gateway IP Address and connect to it in Windows
To find your Gateway IP Address and connect to it on a Mac
- Click Start > Run > type 'cmd' > Click 'Enter'
- Once the Command Prompt window opens, type 'ipconfig /all' and hit 'Enter'
- Locate the line labeled 'Gateway' and make note of the number that follows. It will look similar to '192.168.1.1'
- Open Internet Explorer (or your favorite browser)
- Enter the Gateway IP Address into the address bar and click 'Enter
- Open your Finder and run 'Terminal' inside of Applications > Utilities
- Once the terminal window opens, type 'ipconfig -a' and hit 'Enter'
- Locate the line labeled 'Gateway' and make note of the number that follows. It will look similar to '192.168.1.1'
- Open Safari (or your favorite browser)
- Enter the Gateway IP Address into the address bar and click 'Enter'
- Enable encryption on your access point. Using 128-bit encryption or higher makes your Wireless Network more secure. WEP and WPA are entirely different encryption schemes. WEP has been proven insecure and can be cracked in a few minutes using free utilities that can be downloaded from the Internet. Using at least WPA is recommended, because it is much more secure, but is sometimes a bit harder to set up correctly than WEP is, and isn't completely secure.  Some older access points or wireless cards do not support WPA2. If you have one of these, it is recommended that you purchase a newer one that supports WPA2, depending on how important you consider your security.
- Set the router access password. Anybody who gains access to the router configuration settings can disable the security you have set up. If you forget the password, most routers have a hardware reset that will restore all of the settings to factory defaults. The best option is to use a random sequence of the maximum length of characters - you only have to type that once, so it is not a big thing. When you connect to the router via LAN cable while setting it up, you can copy and paste the password onto the router and onto your local setting, so you never need to type it again.
Use a secure password. Don't use easily guessed passwords for your WPA2 or router access passwords, such as "ABC123", "Password", or a string of numbers in order. Use something hard to guess that contains both upper and lowercase letters as well as numbers. Special characters such as !@#$% are not supported by some routers. The longer the key, the better, although the WPA2 key has a minimum and maximum length. Try to make a little mental effort -- good passwords might be hard to remember, but they are harder to crack.
If you use a weak key then even WPA and WPA2 can be easily cracked within a day using a combination of special precomputed tables and dictionary attacks. The best way to generate a secure key is to use an offline random number generator or write the entire alphabet in uppercase and lowercase and numbers 0-9 on separate pieces of paper, mix the paper up and randomly pick up pieces and return them, mixing them up again each time; each character you pull out becomes a character in your key. You can also try throwing a pair of dice and using the resulting numbers as your password.
- Disable MAC Address filtering on your Access Point or router. A MAC (not to be confused with the computer model 'Mac') address is a code unique to every wireless networking card in existence. MAC Address filtering will register the hardware MAC Address of your networked devices, and only allow devices with known MAC Addresses to connect to your network. However, hackers can clone MAC addresses and still enter your network, so MAC address filtering should not be used in place of proper WPA2 encryption.
- Don't disable the 'SSID Broadcast'. Do not disable the 'SSID Broadcast' feature of your Access Point or router. This seems counter-intuitive, but it is actually a bad idea. Although this would make your network invisible to your neighbors, any determined hacker can still sniff out your SSID; and you are implicitly forcing your computer to shout out your SSID anywhere you are, while it is trying to connect to it. Anyone could then impersonate your router with that SSID, and get your credentials that way.
- Disable remote login. The first router worm brute forces its way into the router in this manner. Most default usernames are set to Admin. It isn't hard for a virus/worm to crack the password if the username is known. The good thing is that routers normally have this disabled by default. Be sure to confirm that it is disabled when you first set up your router and periodically thereafter. If you need to update your router setting remotely, only set up access for the time you are going to be connected.
- Disable wireless administrating. Finally, change the setting that allows administrating the router through a wireless connection to 'off' (meaning that you need to connect with a LAN cable for administration). This disables any wireless hacking into the router.
- Update your software regularly. Regular software updates are one of the most effective steps you can take to improve the overall cybersecurity posture of your home networks and systems. Besides adding new features and functionality, software updates often include critical patches and security fixes for newly discovered threats and vulnerabilities. Most modern software applications will automatically check for newly released updates. If automated updates are not available, consider purchasing a software program that identifies and centrally manages all installed software updates.
- Remove unnecessary services and software. Disable all unnecessary services to reduce the attack surface of your network and devices, including your router. Unused or unwanted services and software can create security holes in a device’s system, which could lead to an increased attack surface of your network environment. This is especially true with new computer systems on which vendors will often pre-install a large number of trial software and applications—referred to as “bloatware”—that users may not find useful. The Cybersecurity and Infrastructure Security Agency (CISA) recommends that you research and remove any software or services that are not being used regularly.
- Adjust factory-default configurations on software and hardware. Many software and hardware products come “out of the box” with overly permissive factory-default configurations intended to make them user-friendly and reduce the troubleshooting time for customer service. Unfortunately, these default configurations are not geared toward security. Leaving them enabled after the installation may create more avenues for an attacker to exploit. Users should take steps to harden the default configuration parameters to reduce vulnerabilities and protect against intrusions.
- Change default log-in passwords and usernames. Most network devices are pre-configured with default administrator passwords to simplify setup. These default credentials are not secure—they may be readily available on the internet, or may even be physically labeled on the device itself. Leaving these unchanged creates opportunities for malicious cyber actors to gain unauthorized access to information, install malicious software, and cause other problems.
- Use strong and unique passwords. Choose strong passwords to help secure your devices. Additionally, do not use the same password with multiple accounts. This way, if one of your accounts is compromised, the attacker will not be able to breach any other of your accounts. (See Choosing and Protecting Passwords for more information.)
- Run up-to-date antivirus software. A reputable antivirus software application is an important protective measure against known malicious threats. It can automatically detect, quarantine, and remove various types of malware, such as viruses, worms, and ransomware. Many antivirus solutions are extremely easy to install and intuitive to use. CISA recommends that all computers and mobile devices on your home network run antivirus software. Additionally, be sure to enable automatic virus definition updates to ensure maximum protection against the latest threats. Note: because detection relies on signatures—known patterns that can identify code as malware—even the best antivirus will not provide adequate protection against new and advanced threats, such as zero-day exploits and polymorphic viruses.
- Install a network firewall. Install a firewall at the boundary of your home network to defend against external threats. A firewall can block malicious traffic from entering your home network and alert you to potentially dangerous activity. When properly configured, it can also serve as a barrier to internal threats, preventing unwanted or malicious software from reaching out to the internet. Most wireless routers come with a configurable, built-in network firewall that includes additional features—such as access controls, web filtering, and denial-of-service (DoS) defense—that you can tailor to fit your networking environment. Keep in mind that some firewall features, including the firewall itself, may be turned off by default. Ensuring that your firewall is on and all the settings are properly configured will strengthen the network security of your network. Note: your internet service provider (ISP) may be able to help you determine whether your firewall has the most appropriate settings for your particular equipment and environment.
- Install firewalls on network devices. In addition to a network firewall, consider installing a firewall on all computers connected to your network. Often referred to as host- or software-based, these firewalls inspect and filter a computer’s inbound and outbound network traffic based on a predetermined policy or set of rules. Most modern Windows and Linux operating systems come with a built-in, customizable, and feature-rich firewall. Additionally, most vendors bundle their antivirus software with additional security features such as parental controls, email protection, and malicious website blocking.
- Regularly back up your data. Make and store—using either external media or a cloud-based service—regular backup copies of all valuable information residing on your device. Consider using a third-party backup application, which can simplify and automate the process. Be sure to encrypt your backup to protect the confidentiality and integrity of your information. Data backups are crucial to minimizing the impact if that data is lost, corrupted, infected, or stolen.
- Increase wireless security. Follow the steps below to increase the security of your wireless router. Note: consult your router’s instruction manual or contact your ISP for specific instructions on how to change a particular setting on your device.
- Use the strongest encryption protocol available. CISA recommends using the Wi-Fi Protected Access 3 (WPA3) Personal Advanced Encryption Standard (AES) and Temporary Key Integrity Protocol (TKIP), which is currently the most secure router configuration available for home use. It incorporates AES and is capable of using cryptographic keys of 128, 192, and 256 bits. This standard has been approved by the National Institute of Standards and Technology (NIST).
- Change the default service set identifier (SSID). Sometimes referred to as the “network name,” an SSID is a unique name that identifies a particular wireless local area network (WLAN). All wireless devices on a Wireless Local Area Network (WLAN) must use the same SSID to communicate with each other. Because the device’s default SSID typically identifies the manufacturer or the actual device, an attacker can use this to identify the device and exploit any of its known vulnerabilities. Make your SSID unique and not tied to your identity or location, which would make it easier for the attacker to identify your home network.
- Disable Wi-Fi Protected Setup (WPS). WPS provides simplified mechanisms for a wireless device to join a Wi-Fi network without the need to enter the wireless network password. However, a design flaw in the WPS specification for PIN authentication significantly reduces the time required for a cyberattacker to brute force an entire PIN, because it informs them when the first half of the eight-digit PIN is correct. Many routers lack a proper lockout policy after a certain number of failed attempts to guess the PIN, making a brute-force attack much more likely to occur. See Brute Force Attacks Conducted by Cyber Actors.
- Reduce wireless signal strength. Your Wi-Fi signal frequently propagates beyond the perimeters of your home. This extended emission allows eavesdropping by intruders outside your network perimeter. Therefore, carefully consider antenna placement, antenna type, and transmission power levels. By experimenting with your router placement and signal strength levels, you can decrease the transmitting coverage of your Wi-Fi network, thus reducing this risk of compromise. Note: while this reduces your risk, a motivated attacker may still be able to intercept a signal that has limited coverage.
- Turn the network off when not in use. While it may be impractical to turn the Wi-Fi signal off and on frequently, consider disabling it during travel or extended periods when you will not need to be online. Additionally, many routers offer the option to configure a wireless schedule that will automatically disable the Wi-Fi at specified times. When your Wi-Fi is disabled, you prevent outside attackers from being able to exploit your home network.
- Disable Universal Plug and Plan (UPnP) when not needed. UPnP is a handy feature that allows networked devices to seamlessly discover and establish communication with each other on the network. However, though the UPnP feature eases initial network configuration, it is also a security risk. Recent large-scale network attacks prove that malware within your network can use UPnP to bypass your router’s firewall, allow attackers to take control of your devices remotely, and spread malware to other devices. You should therefore disable UPnP unless you have a specific need for it.
- Upgrade firmware. Check your router manufacturer’s website to ensure you are running the latest firmware version. Firmware updates enhance product performance, fix flaws, and address security vulnerabilities. Note: some routers have the option to turn on automatic updates.
- Disable remote management. Most routers offer the option to view and modify their settings over the internet. Turn this feature off to guard against unauthorized individuals accessing and changing your router’s configuration.
- Monitor for unknown device connections. Use your router manufacturer’s website to monitor for unauthorized devices joining or attempting to join your network. Also, see the manufacturer’s website for tips on how to prevent unauthorized devices from connecting to your network.
- Mitigate Email Threats. Phishing emails continue to be one of the most common initial attack vectors employed for malware delivery and credential harvesting. Attacking the human element—considered the weakest component in every network—continues to be extremely effective. To infect a system, the attacker simply has to persuade a user to click on a link or open an attachment. The good news is that there are many indicators that you can use to quickly identify a phishing email. The best defense against these attacks is to become an educated and cautious user and familiarize yourself with the most common elements of a phishing attack.
- Use a security-focused DNS service provider. By default, your router will be configured to forward Domain Name System (DNS) requests to your ISP, which means you have to trust your ISP to maintain a secure DNS lookup service. Since DNS acts as the internet’s phone book, locating the IP addresses of the websites you want to visit, hackers commonly target it to direct users to malicious websites in a way that’s typically hard to spot. Companies like Google, Cloudflare, OpenDNS (Cisco), and others offer publicly available DNS resolvers that are security-focused and even have encrypted versions.