Check to see if the end device is connected to the internet. Sometimes it's as simple as right-clicking and hitting connect on the wifi icon.
DHCP server is misconfigured or service needs restarted.
Use ipconfig /all in an administrative command prompt: Check the desired adapter and see if it has an APIPA address (range: 169.254. 0.1-169.254. 255.254). This could indicate an issue with DHCP.
The appropriate VLAN(S) have not been set on the Access Point, Switch, or Other network device.
If you can ping the IP Address but not the Hostname usually this is an indication of an issue with DNS
A physical cable or device may be disconnected or no longer working
IP conflict?! Particularly in ranges that have statically set IP Addresses but also possible in non-static environments.
Check to see if duplicate IPs are listed on your DHCP server or use an IP scanner software and see if the correct mac-address comes up for your device.
All network devices communicating over internet essentially need three things:
An IP Address, a subnet mask, and a (default) gateway.
Make sure these settings are correct and match either DHCP or the switch/router/firewall/etc settings.
The firewall may be blocking the traffic. This could either be on the end device or the actual firewall for your organization.
Check each device along the network path to see where the connectivity stops.
I.E. End device -> Access Point -> Switch -> Router -> Firewall. Etc.
If you are still stuck. Try gathering more information that may lead to the discovery of the issue:
Is it a particular model of device?
Is it a particular location or section of a location?
Is it wireless only, ethernet only, etc..?
Is it during certain times or continuous?
Is it a particular group of people?
Is it the issue that was presented to you?
Sometimes the user will tell you I have no internet when what they really
mean is: “I can’t get to a website that I should not be going to”