The next step requires a more detailed explanation. There are three options available. You can use the any parameter to permit or deny any host or network, you can use an IP address to specify either a single host or a range of them, or you can use the host command to specify a specific host only. The any command is pretty obvious—any source address matches the statement, so every packet compared against this line will match. The host command is relatively simple. Here’s an example using it :