- A Cloud Guru
In this hands-on lab, we will walk though troubleshooting DNS resolution issues on the provided host.
Table of Contents
Verify the Issue and Check `/etc/nsswitch.conf`
We'll first need to verify that the issue exists by attempting the
curlthe header of
curl -I https://acloudguru.com/
Then we need to verify that nothing is missing in this file, and we should pay attention to the ordering of the
hosts: files dns myhostname
Verify `/etc/hosts` Contents
We'll want to make sure there aren't any entries in this file that would cause issues:
Determine If the DNS Host is Listening on TCP Port 53
If the host is listening on TCP port 53, we'll know by running this:
telnet 10.0.1.1 53
Check Resolution Using the 10.0.0.2 DNS Host
Now that we've verified that the host listed in
/etc/resolv.confisn't available on TCP port 53, check if resolution is working on the DNS host
dig @10.0.0.2 acloudguru.com
Change the Configuration to Use the 10.0.0.2 Host
We can do this with network manager, or by editing
/etc/resolv.conf. If we restart networking, this is the IP that will be used via DHCP. Remove the
What's a lab?
Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.