cityssm/is-private-network-address

const localhost = "localhost";
const localhost_v4_127 = "127.0.0.1";
const localhost_v6 = "::1";
const localhost_node = "::ffff:127.0.0.1";
const range_v4_10 = /^(::ffff:)?10(\.\d{1,3}){3}$/;
const range_v4_172 = /^(::ffff:)?172\.(1[6-9]|2\d|3[01])(\.\d{1,3}){2}$/;
const range_v4_192 = /^(::ffff:)?192\.168(\.\d{1,3}){2}$/;
const range_v6_fc = /^f[cd][\da-f]{0,2}(:([\da-f]){0,4}){0,7}$/;
export const isLocal = (networkAddress) => {
    switch (networkAddress.toLowerCase()) {
        case localhost:
        case localhost_v4_127:
        case localhost_v6:
        case localhost_node:
            return true;
    }
    return false;
};
export const isPrivate = (networkAddress) => {
    const networkAddressLowerCase = networkAddress.toLowerCase();
    if (range_v4_10.test(networkAddressLowerCase) ||
        range_v4_172.test(networkAddressLowerCase) ||
        range_v4_192.test(networkAddressLowerCase) ||
        range_v6_fc.test(networkAddressLowerCase) ||
        isLocal(networkAddressLowerCase)) {
        return true;
    }
    return false;
};