On your Mac, use the Clients options in Content Caching settings to specify the devices that can access the content cache on this computer.
To change these settings, choose Apple menu > System Settings, click General in the sidebar, click Sharing on the right, click the Info button next to Content Caching, press and hold the Option key and click Advanced Options, then click Clients. (You may need to scroll down.)
Option
Description
Cache content for
Select an option that describes which devices this computer caches content for:
Devices using the same public IP address: This computer caches content for devices that use the same public IP address as this computer.
Devices using the same local networks: This computer caches content for devices that use the same local networks as this computer.
Devices using custom local networks: This computer caches content for devices that use the specified local networks.
Devices using custom local networks with fallback: This computer caches content for devices that use the specified local networks, and for devices that use the same public IP address as this computer when their preferred content cache is unavailable.
My local networks
Select an option that describes your network:
Use one public IP address: Select this option when you have just one public IP address. The public IP address is discovered automatically.
Use custom public IP addresses: Select this option to use a specific public IP address, or if you use multiple public IP addresses. If you select this option, additional DNS configuration is required.
Add
To specify a custom local network, click the Add button , then enter the starting and ending IP addresses. The addresses can be the same, to create a range of just one address.
Remove
To remove a custom local network, select the address range, then click the Remove button .
DNS Configuration
Click to generate configuration for a DNS TXT record. This button is available only if you select “use custom public IP addresses” for the “My local networks” option.
in the sidebar, click Sharing on the right, click the Info button 
next to Content Caching, press and hold the Option key and click Advanced Options, then click Clients. (You may need to scroll down.)
