Avoid using a VPN-assigned IP address as your caching server’s primary IP

Your computers and devices might not be able to use your caching server if you assign it a VPN-provided IP address.

If you use an IP address assigned from a VPN connection as a caching server’s primary IP address, you might see these issues:

• The caching server's cache might be flushed when the VPN connection is established or terminated.

• Macs and iOS devices on your server's network might not use the caching server.

Note: Using OS X Server’s VPN service along side the Caching service is supported. This article describes potential issues where a server’s primary IP address changes due to using VPN client software.

To determine which IP address is being used as a caching server's primary address, use these steps:

1. Open Server app.

2. Select your server’s name in the sidebar.

3. Click the Overview tab.

4. Note the address listed next to Internet.

If you haven’t opted into Reachability, your public IP doesn't appear next to Internet. You can use this terminal command as an administrator to find your caching server's primary address:

sudo grep public /Library/Server/Caching/Logs/Debug.log

The value returned after "Got back public IP" indicates the IP address being used by the Caching service. For example:

2015-03-17 13:34:30.046 Got back public IP 1.2.3.4