How can I troubleshoot and resolve the issue of “could not resolve host:GitHub.com”?

 In the context of DevOps, here are the steps given to troubleshoot this particular error:-

Checking your internet connection

You should try to ensure that you are properly connected to the Internet and can access other websites.

Checking the DNS Configuration

You can also try to use a different DNS server, such as Google’s DNS or even Cloudflare’s DNS.

Checking your host file

You should try to ensure that GitHub.com is not incorrectly listed in your particular host's file.

Testing with a different network

You should also try to connect to a different wi fi network or even you can use a mobile hotspot to see if the issue persists.

Checking your proxy settings

You should try to ensure that your proxy settings should be correctly configured if you are trying to use a proxy server.

Restarting your router

Sometimes, simply restarting your particular router can fix your issue of DNS issue.

Updating git

You should try to ensure that you have the latest version of Git installed. Sometimes, the update of git can resolve the connectivity issues.

Here is the Java program Given of how you can diagnose network connectivity to GitHub:-

Import java.io.BufferedReader;

Import java.io.IOException;

Import java.io.InputStreamReader;

Import java.net.InetAddress;

Import java.net.HttpURLConnection;

Import java.net.URL;

Public class GitHubConnectivityChecker {

    Public static void main(String[] args) {

        String host = “github.com”;

        Int timeout = 5000;

        // Step 1: Check Internet Connectivity

        If (!isInternetAvailable()) {

            System.out.println(“No internet connection.”);

            Return;

        }

        // Step 2: DNS Resolution Check

        If (!isHostResolvable(host)) {

            System.out.println(“DNS resolution failed for host: “ + host);

            Return;

        }

        // Step 3: Ping the Host

        If (!pingHost(host, timeout)) {

            System.out.println(“Ping failed for host: “ + host);

            Return;

        }

        // Step 4: HTTP Connectivity Check

        If (!checkHTTPConnection(https://github.com)) {

            System.out.println(“HTTP connectivity check failed for GitHub.”);

            Return;

        }

        System.out.println(“All checks passed. GitHub is reachable.”);

    }

    Private static boolean isInternetAvailable() {

        Try {

            InetAddress address = InetAddress.getByName(“8.8.8.8”);

            Return address.isReachable(5000);

        } catch (IOException e) {

            System.out.println(“Internet connectivity check failed: “ + e.getMessage());

            Return false;

        }

    }

    Private static boolean isHostResolvable(String host) {

        Try {

            InetAddress.getByName(host);

            Return true;

        } catch (IOException e) {

            System.out.println(“DNS resolution error: “ + e.getMessage());

            Return false;

        }

    }

    Private static boolean pingHost(String host, int timeout) {

        Try {

            InetAddress inet = InetAddress.getByName(host);

            Return inet.isReachable(timeout);

        } catch (IOException e) {

            System.out.println(“Ping error: “ + e.getMessage());

            Return false;

        }

    }

    Private static boolean checkHTTPConnection(String urlStr) {

        Try {

            URL url = new URL(urlStr);

            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            Connection.setRequestMethod(“GET”);

            Connection.setConnectTimeout(5000);

            Connection.setReadTimeout(5000);

            Int responseCode = connection.getResponseCode();

            Return responseCode == 200;

        } catch (IOException e) {

            System.out.println(“HTTP connection error: “ + e.getMessage());

            Return false;

        }

    }

}