Fixing GitHub Access Issue on Ubuntu: Cannot Ping or Connect to GitHub

In this article, we will delve into a common issue faced by Ubuntu users: not being able to ping or connect to GitHub. This problem is often due to a DNS issue, and we will discuss how to resolve it in detail.

Understanding the Problem

The inability to access GitHub on an Ubuntu machine, while other devices on the same network can, is typically a DNS-related issue. This is often confirmed by the discrepancy in the IP address obtained through nslookup for GitHub.

What is DNS?

DNS (Domain Name System) is the phonebook of the internet. Humans access information online through domain names, like github.com or google.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources.

Confirming the Issue

To confirm if this is a DNS issue, you can use the nslookup command. This command is used to query the DNS and get the IP address corresponding to the domain name. Here’s how to use it:

nslookup github.com

If the IP address obtained through this command is different from the expected IP address (which you can confirm by running the same command on a device that can access GitHub), it confirms that the problem is with DNS resolution.

How to Fix the Issue

There are two main ways to resolve this issue:

1. Change the Nameserver

You can attempt to change the nameserver to a public nameserver like Google DNS (8.8.8.8), OpenDNS (206.67.220.220), or Level 3 (209.244.0.3).

The method for changing the nameserver depends on the Ubuntu release. For recent releases, it can be done through netplan settings. Here’s how to do it:

Open the netplan configuration file using your preferred text editor. We’ll use nano for this example:

sudo nano /etc/netplan/01-netcfg.yaml

In the opened file, add the nameservers as follows:

network:
 version: 2
 renderer: networkd
 ethernets:
 enp3s0:
 dhcp4: yes
 dhcp4-overrides:
 use-dns: false
 dhcp6: yes
 dhcp6-overrides:
 use-dns: false
 nameservers:
 addresses: [8.8.8.8, 8.8.4.4]

Save the file and apply the changes:

sudo netplan apply

Now, try accessing GitHub again.

2. Report the Issue to the ISP

If the IP address obtained through nslookup is the ISP’s nameserver, it is recommended to report the issue to their technical support. They can investigate and fix the problem on their end.

Conclusion

It’s important to note that the IP address for GitHub can vary depending on the location and DNS resolution. Different DNS servers may provide different IP addresses for the same domain.

By following the steps outlined in this article, you should be able to resolve the issue of not being able to ping or connect to GitHub on your Ubuntu machine. If the problem persists, consider reaching out to your ISP or seeking help from the Ubuntu community.