The 'DNS not responding' error occurs when the device cannot convert a website name into its corresponding IP address, which prevents browsing. Generally, this failure is caused by instability in the internet provider, corrupted data in the local cache, or blocks imposed by antivirus and firewalls.
Five Actions to Fix the Problem
There are several measures that can be taken to solve this issue. It is possible to restart both the modem and the device itself, clear the system cache, or replace the default DNS with more reliable options. If the problem persists, it is recommended to check if the network drivers are outdated or if security settings are obstructing communication.
Step 1: Restart Devices
Restarting the modem clears the internal data cache, removing damaged information that may be locking up the device. This procedure forces a new synchronization with the internet provider, updating the DNS address map. In the case of computers or mobile phones, restarting resets the TCP/IP traffic rules and the local network history, resolving temporary conflicts and restoring a stable connection to the router.
Step 2: Clear DNS Cache
Clearing the DNS cache aims to erase old or defective address records stored in the system. This forces the device to look for an updated IP address directly from the servers, reestablishing the correct connection path. In Windows, this is done through the Command Prompt run as administrator, typing the command ipconfig /flushdns and restarting the PC. On macOS, the process involves opening Terminal and running the command sudo killall -HUP mDNSResponder, thus restarting Apple's connection service.
Step 3: Change Default DNS Server
Changing the DNS server provided by the provider to external options helps prevent interruptions when the original address is unstable. It is suggested to use Google DNS (8.8.8.8) or Cloudflare DNS (1.1.1.1), both recognized for their stability. In Windows, you must access the Properties of the active network connection, enter the TCP/IPv4 protocol, and manually insert the new addresses. On macOS, the user accesses System Settings, goes to Network, selects the active connection, clicks Details, and adds the new servers in the DNS tab.
Step 4: Update Network Drivers
Keeping network drivers updated corrects communication failures between the operating system and the physical internet card. This correction eliminates data packet loss, allowing DNS queries to complete successfully. In Windows, this maintenance is performed via Device Manager, expanding the 'Network adapters' section, right-clicking the active card, and choosing 'Update driver'. For macOS, these essential components are integrated into Apple's closed system and are updated automatically when installing new versions of the operating system.
Step 5: Configure Firewall and Antivirus
Security software, such as antivirus and firewalls, can inadvertently block the UDP port, which is used by DNS traffic. This excessive protection prevents the device from receiving website responses, generating the connection error. To resolve this, it is necessary to check the traffic rules and network permissions in the security tool, ensuring that the flow of the browser and internet adapters is not being blocked. As a quick test, you can temporarily disable these defenses; if browsing normalizes, simply add the DNS servers to the security program's exception list.
Additional Causes of DNS Error
The 'DNS server not responding' error can have various origins. It may be instability or overload on the provider's DNS server. Another common cause is corrupted data in the local cache, causing the system to attempt non-existent routes. Security software can block traffic on the UDP port. Failures in the home router's firmware can also freeze redirection functions. Furthermore, outdated network drivers cause conflicts and packet loss, and conflicts with VPNs or proxies can interrupt browsing.
Diagnosing the Source of the Failure
To determine whether the problem lies with the router or the device, it is possible to test by connecting a second device, such as another smartphone or laptop, to the same network. If all devices show the error, the fault is with the router or the provider. An additional effective test is to use the mobile data on the problematic device; if browsing returns to normal, it confirms that the DNS failure is limited to the home router.
Importance of DNS
DNS acts as the internet's phone book, converting easy-to-remember website names into numerical IP addresses that machines require. Without this conversion function, devices cannot locate servers, and browsing stops. In addition to establishing paths, the system optimizes connections through local caches and offers protection against cyberattacks, simplifying the network architecture.
