Provide a Caching server
After you start Caching service, you can:
Customize the service for your network
Customize the cache file location
Choose the maximum cache size
Clear the cache
You can decide what network the caching clients can connect from. See Server access overview.
To learn more about how Caching service works, and best practices, see About Caching service.
You can find the current list of supported content types in the Apple Support article Content types supported by the Caching service.
If you provide caching service for clients with public IP addresses, you need to add or edit a DNS TXT record for your caching server. See DNS settings for Caching without a NAT.
Cache for clients connecting from all networks or only the local subnet
In the Server app Caching pane, click Edit next to Permissions.
Click the “Cache content for clients connecting from” pop-up menu, then choose one of the following:
Click the “Serve clients with public addresses” pop-up menu, then choose one of the following:
If you selected “on other networks,” add an IP address group by clicking Add 
, then choosing the IP address group name.
If the IP address group you want isn’t listed as a choice, you can create it here.
To create a different IP address range, click Add , then choose “Create a new network.”
Enter the IP address group name, a starting IP address, and an ending IP address.
You can put an address range in CIDR notation (for example, 10.0.0.1/16) in the Start IP Address field, and the ending address will be automatically entered.
When you’ve added the desired IP address group, click Create.
You may need to add (or augment) a DNS record for the caching server. Click Client Configuration to get the DNS record settings.
When you’ve finished configuration, click OK.
Cache for clients connecting from only some networks
In the Server app Caching pane, click Edit next to Permissions.
Click the “Cache content for clients connecting from” pop-up menu, then choose "only some networks.”
Add local subnets by clicking Add , then choose an IP address group name.
If the IP address group you want isn’t listed as a choice, you can create it here.
To create a different IP address range, click Add , then choose “Create a new network.”
Enter the IP address group name, a starting IP address, and an ending IP address.
You can put an address range in CIDR notation (for example, 10.0.0.1/16) in the Start IP Address field, then the ending address will automatically be entered.
When you’ve added the desired IP address group, click Create.
Click the “Serve clients with public addresses” pop-up menu, then choose one of the following:
If you selected “on other networks,” add an IP address group by clicking Add , then choosing the IP address group name.
If the IP address group you want isn’t listed as a choice, you can create it here.
To create a different IP address range, click Add , then choose “Create a new network.”
Enter the IP address group name, a starting IP address, and an ending IP address.
You can put an address range in CIDR notation (for example, 10.0.0.1/16) in the Start IP Address field, then the ending address will automatically be entered.
When you’ve added the desired IP address group, click Create.
You may need to add (or augment) a DNS record for the caching server. Click Client Configuration to get the DNS record settings.
When you’ve finished configuration, click OK.
Select a volume for caching
In the Server app Caching pane, click Edit next to Volume.
Select a storage volume, then click Choose.
Delete all cached content
In the Server app Caching pane, click Reset.
If you’re sure you want to proceed, click Reset again.