public static void setWhitelistedIPs(Set<String> allowed) {
        if (allowed == null) {
            throw new NullPointerException();
        }
        allowedIPs = allowed;
        if (allowedIPs.isEmpty()) {
            JiveGlobals.deleteProperty(ConnectionSettings.Client.LOGIN_ALLOWED);
        }
        else {
            // Iterate through the elements in the map.
            StringBuilder buf = new StringBuilder();
            Iterator<String> iter = allowedIPs.iterator();
            if (iter.hasNext()) {
                buf.append(iter.next());
            }
            while (iter.hasNext()) {
                buf.append(", ").append(iter.next());
            }
            JiveGlobals.setProperty(ConnectionSettings.Client.LOGIN_ALLOWED, buf.toString());
        }
    }
Sets the list of IP address that are allowed to connect to the server. If the list is empty then anyone not on
{@link #getBlacklistedIPs()} is  allowed to connect to the server except for anonymous users that are subject to
{@link #getWhitelistedAnonymousIPs()}. This list is used for both anonymous and non-anonymous users.

Note that blacklisting takes precedence over whitelisting: if an address is matched by both, access is denied.

@param allowed the list of IP address that are allowed to connect to the server. Can be empty, but not null.
xmppserver/src/main/java/org/jivesoftware/openfire/session/LocalClientSession.java