DNS Resolution Issue¶

Check Static IP Configuration:

Verify that your static IP configuration (address, netmask, gateway) is correctly set to match your network.

When troubleshooting network issues, especially those related to DNS resolution and IP configuration, you may need to check several configuration files and settings on your Linux system. Here are some of the key files and areas to check:

/etc/network/interfaces or Network Manager:

Check this file if you are manually configuring network interfaces. It contains network interface definitions, IP addresses, netmasks, gateways, and DNS server settings.
/etc/resolv.conf :

This file contains DNS configuration information, including the DNS server(s) your system should use for name resolution. Ensure that it points to valid DNS servers. It's often managed dynamically by network services or NetworkManager.
/etc/hosts :

This file allows you to define static IP address-to-hostname mappings. Ensure that there are no conflicting entries that might interfere with DNS resolution.
Network Manager (if used):

If you're using Network Manager, check its settings for network profiles and DNS configuration. You can often configure DNS servers through the GUI or command-line tools like nmcli.
Router/Modem Configuration:

Access your router or modem's web interface and verify its DNS settings. Make sure it's not overriding the DNS servers you set on your device.
Firewall Rules:

Check your firewall rules (iptables, ufw, etc.) to ensure they are not blocking DNS traffic or network connectivity.
Systemd-Resolved Configuration (if used):

If your system uses systemd-resolved, check its configuration (/etc/systemd/resolved.conf) to ensure it's set up correctly.
Proxy and VPN Settings:

If you use a proxy or VPN, check their settings to ensure they are not interfering with network connectivity.
System Logs:

Review system logs (/var/log/syslog, /var/log/messages, etc.) for any network-related error messages or issues.
Network Service Restart:

After making changes to network configuration files, restart network services to apply the changes. For example, you can use systemctl restart networking (Debian/Ubuntu) or systemctl restart network (CentOS/Fedora).