Problems with the DNS servers from your internet service provider can compromise the functionality of certain Avast products. You may experience the following issues:
- Avast installation or update repeatedly fails.
- Avast does not accept your valid activation code, so you are unable to activate a paid subscription.
- Avast SecureLine VPN cannot establish an internet connection, or you cannot browse the internet while connected to Avast SecureLine VPN.
- Avast Secure Browser does not allow website access.
To troubleshoot these issues, Avast Support may request that you change your internet connection settings to use DNS servers from a different provider, such as Cisco, Google, Cloudflare, or Quad9.
Change DNS settings
To change your DNS settings on a Windows device, select the relevant tab below according to your Windows version.
- Sign in to Windows as a user with administrator permissions.
For information about user accounts with administrator permissions, refer to the following article: Managing administrative accounts on your Windows PC.
- Right-click the Windows
Start icon and select Settings. - From the left panel, select Network & internet, then click Advanced network settings.
- Under Related settings, click More network adapter options.
- Click the Windows Start icon and select Settings (the gear icon).
- On the Windows Settings screen, click Network & Internet.
- Under Change your network settings, click Change adapter options.
- On your keyboard, press the Windows logo key and
Xkey simultaneously. - Select Control Panel from the menu that appears.
- Follow option A or option B below according to your view:
- Default category view: Under Network and Internet, click View network status and tasks.
- Large/small icons view: Click Network and Sharing Center.
- Default category view: Under Network and Internet, click View network status and tasks.
- Select Change adapter settings from the left panel of the Network and Sharing Center window.
- Click the Windows Start icon and select Control Panel.
- Follow option A or option B below according to your view:
- Default category view: Under Network and Internet, click View network status and tasks.
- Large/small icons view: Click Network and Sharing Center.
- Default category view: Under Network and Internet, click View network status and tasks.
- Select Change adapter settings from the left panel of the Network and Sharing Center window.
- Based on your current connection type, right-click the relevant Ethernet or Wi-Fi adapter in the Network Connections list, then select Properties from the context menu.
- Based on your current connection type, right-click Local Area Connection or Wireless Network Connection in the Network Connections list, then select Properties from the context menu.
- If prompted by the User Account Control dialog for permission, click Yes.
- Select Internet Protocol Version 4 (TCP/IPv4) from the list, then click Properties.
- Select Use the following DNS server addresses, then choose one of the public DNS providers from the table below and enter both IP addresses (preferred and alternate) into the relevant boxes. Click OK to confirm.
DNS provider Preferred DNS server address Alternate DNS server address Cisco OpenDNS 208.67.222.222 208.67.220.220 Google Public DNS 8.8.8.8 8.8.4.4 Cloudflare 1.1.1.1. 1.1.1.1 1.0.0.1 Quad9 9.9.9.9 149.112.112.112 Do not change anything in the upper section related to IP address, Subnet mask and Default gateway. - If the Windows Network Diagnostics window appears, click CancelClose to exit.
- On your keyboard, press the Windows logo key and
Rkeys simultaneously to run the Windows Services console. - Enter
cmdinto the Open field and click OK. - In the Command Prompt window that appears, enter
ipconfig /flushdnsand pressEnteron your keyboard.
Start icon and select Settings. 
Start icon and select 
Settings (the gear icon). 
Start icon and select Control Panel. 
- Sign in to your Mac as a user with administrator permissions.
- In the menu bar, click the Apple icon ▸ System Preferences..., then select Network.
- Based on your current connection type, select the relevant Ethernet or Wi-Fi connection from the left menu, then click Advanced....
- Select the DNS tab, then click the + plus icon to add a server to the list.
- Choose one of the public DNS providers from the table below, then enter the DNS server address into the DNS Servers field. Click OK to confirm.
DNS provider DNS server address Cisco OpenDNS 208.67.222.222 Google Public DNS 8.8.8.8 Cloudflare 1.1.1.1. 1.1.1.1 Quad9 9.9.9.9
These steps may differ slightly depending on your device model, Android version, and vendor customizations.
- Open your device Settings and select Connections ▸ Wi-Fi.
- Select the Wi-Fi network you are connected to from the list.
- Tap View more ▸ IP settings and select Static to open DNS settings.
- Delete any existing DNS servers under DNS 1 and DNS 2, then choose one of the public DNS providers from the table below and enter the DNS server address into the DNS 1 field. Tap Save to confirm.
DNS provider DNS server address Cisco OpenDNS 208.67.222.222 Google Public DNS 8.8.8.8 Cloudflare 1.1.1.1. 1.1.1.1 Quad9 9.9.9.9
- Open your device Settings and select Wi-Fi.
- Select the Wi-Fi network you are connected to from the list.
- Tap Configure DNS to open DNS settings.
- Select Manual and tap the red circle icon next to any existing DNS servers to remove them.
- Choose one of the public DNS providers from the table below, then tap Add Server and enter the DNS server address into the DNS servers field. Tap Save to confirm.
DNS provider DNS server address Cisco OpenDNS 208.67.222.222 Google Public DNS 8.8.8.8 Cloudflare 1.1.1.1. 1.1.1.1 Quad9 9.9.9.9
Your DNS settings are now changed.
- All Avast consumer software products
- All supported platforms
Updated on: 02/06/2022
