In a setup where a single server can handle many clients, it is sometimes necessary to set per-client options that overrule the global options, or to add extra options to a particular client. The option
client-config-dir is very useful for this. It allows the VPN administrator to assign a specific IP address to a client, in order to push specific options such as a DNS server to a particular client or to temporarily disable a client altogether. This option is also vital if you want to route a subnet from the client side to the server side, as we will see later on.
client-config-dir or CCD file can contain the following options: