Renewing your IP address often fixes minor glitches and connectivity issues. Your Mac will ask your DHCP server---often your Wi-Fi router---for a new IP address and connect using either the same one or a new one, depending on the details your router provides.

To find these settings, click the "Apple" icon in the upper-right corner of the menu bar, and select "System Preferences."

apple menu and system preferences

Click "Network" in the System Preferences window.

network settings

Choose the appropriate network and click the "Advanced" button. This works with both wired (Ethernet) and wireless (Wi-Fi) connections.

advanced connectivity settings

The next screen should default to the Wi-Fi tab. Choose "TCP/IP" instead, just to the right of it.

tcp/ip settings

Click the "Renew DHCP License" button and then click "OK" once the renewal is complete. Clicking this button instructs your Mac to obtain new routing information from the DHCP server.

renew dhcp lease mac

Resetting this could improve your Mac's connectivity, especially if you've recently changed router settings.