diff --git a/includes/dhcp.php b/includes/dhcp.php
index e498b962..5f8a0ca7 100755
--- a/includes/dhcp.php
+++ b/includes/dhcp.php
@@ -8,142 +8,12 @@ require_once 'config.php';
  */
 function DisplayDHCPConfig()
 {
-
     $status = new StatusMessages();
     if (!RASPI_MONITOR_ENABLED) {
         if (isset($_POST['savedhcpdsettings'])) {
-            $errors = '';
-            define('IFNAMSIZ', 16);
-            if (!preg_match('/^[a-zA-Z0-9]+$/', $_POST['interface']) 
-                || strlen($_POST['interface']) >= IFNAMSIZ
-            ) {
-                $errors .= _('Invalid interface name.').'<br />'.PHP_EOL;
-            }
-
-            if (!preg_match('/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\z/', $_POST['RangeStart']) 
-                && !empty($_POST['RangeStart'])
-            ) {  // allow ''/null ?
-                $errors .= _('Invalid DHCP range start.').'<br />'.PHP_EOL;
-            }
-
-            if (!preg_match('/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\z/', $_POST['RangeEnd']) 
-                && !empty($_POST['RangeEnd'])
-            ) {  // allow ''/null ?
-                $errors .= _('Invalid DHCP range end.').'<br />'.PHP_EOL;
-            }
-
-            if (!ctype_digit($_POST['RangeLeaseTime']) && $_POST['RangeLeaseTimeUnits'] !== 'infinite') {
-                $errors .= _('Invalid DHCP lease time, not a number.').'<br />'.PHP_EOL;
-            }
-
-            if (!in_array($_POST['RangeLeaseTimeUnits'], array('m', 'h', 'd', 'infinite'))) {
-                $errors .= _('Unknown DHCP lease time unit.').'<br />'.PHP_EOL;
-            }
-
-            $return = 1;
-            if (empty($errors)) {
-                $config = 'interface='.$_POST['interface'].PHP_EOL.
-                    'dhcp-range='.$_POST['RangeStart'].','.$_POST['RangeEnd'].
-                    ',255.255.255.0,';
-                if ($_POST['RangeLeaseTimeUnits'] !== 'infinite') {
-                    $config .= $_POST['RangeLeaseTime'];
-                }
-
-                $config .= $_POST['RangeLeaseTimeUnits'].PHP_EOL;
-
-                for ($i=0; $i < count($_POST["static_leases"]["mac"]); $i++) {
-                    $mac = trim($_POST["static_leases"]["mac"][$i]);
-                    $ip  = trim($_POST["static_leases"]["ip"][$i]);
-                    if ($mac != "" && $ip != "") {
-                        $config .= "dhcp-host=$mac,$ip".PHP_EOL;
-                    }
-                }
-
-                if ($_POST['no-resolv'] == "1") {
-                    $config .= "no-resolv".PHP_EOL;
-                }
-                foreach ($_POST['server'] as $server) {
-                    $config .= "server=$server".PHP_EOL;
-                }
-                if ($_POST['log-dhcp'] == "1") {
-                  $config .= "log-dhcp".PHP_EOL;
-                }
-                if ($_POST['log-queries'] == "1") {
-                  $config .= "log-queries".PHP_EOL;
-                }
-                if ($_POST['DNS1']) {
-                    $config .= "dhcp-option=6," . $_POST['DNS1'];
-                    if ($_POST['DNS2']) {
-                        $config .= ','.$_POST['DNS2'];
-                    }
-                    $config .= PHP_EOL;
-                }
-
-                $config .= "log-facility=/tmp/dnsmasq.log".PHP_EOL;
-                $config .= "conf-dir=/etc/dnsmasq.d".PHP_EOL;
-                file_put_contents("/tmp/dnsmasqdata", $config);
-
-                $iface = $_POST['interface'];
-                // handle DHCP for selected interface option
-                if ($_POST['dhcp-iface'] == "1") {
-                    $net_cfg = RASPI_CONFIG_NETWORKING.'/'.$iface.'.ini';
-                    if (!file_exists($net_cfg) || filesize($net_cfg) ==0 ) {
-                        $status->addMessage('Static IP address for '.$iface.' not found.', 'danger');
-                        $status->addMessage('Configure this interface in Networking > '.$iface.'.', 'danger');
-                        $return = 1;
-                    } else {
-                        $dhcp_cfg = file_get_contents(RASPI_DHCPCD_CONFIG);
-                        if (!preg_match('/^interface\s'.$iface.'$/m', $dhcp_cfg)) {
-                            // set dhcp values from ini
-                            $iface_cfg = parse_ini_file($net_cfg, false, INI_SCANNER_RAW);
-                            $ip_address = $iface_cfg['ip_address'];
-                            $domain_name_server = ($iface_cfg['domain_name_server'] =='') ? '1.1.1.1 8.8.8.8' : $iface_cfg['domain_name_server'];
-
-                            // append interface config to dhcpcd.conf
-                            $cfg = $dhcp_conf;
-                            $cfg[] = '# RaspAP '.$_POST['interface'].' configuration';
-                            $cfg[] = 'interface '.$_POST['interface'];
-                            $cfg[] = 'static ip_address='.$ip_address;
-                            $cfg[] = 'static domain_name_server='.$domain_name_server;
-                            $cfg[] = PHP_EOL;
-                            $cfg = join(PHP_EOL, $cfg);
-                            $dhcp_cfg .= $cfg;
-                            file_put_contents("/tmp/dhcpddata", $dhcp_cfg);
-                            system('sudo cp /tmp/dhcpddata '.RASPI_DHCPCD_CONFIG, $return);
-                            $status->addMessage('DHCP configuration for '.$iface.' added.', 'success');
-                            system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_PREFIX.$iface.'.conf', $return);
-                            $status->addMessage('Dnsmasq configuration for '.$iface.' added.', 'success');
-                        } else {
-                            $status->addMessage('DHCP for '.$iface.' already enabled.', 'danger');
-                        }
-                    }
-                } elseif (($_POST['dhcp-iface'] == "0") && file_exists(RASPI_DNSMASQ_PREFIX.$iface.'.conf')) {
-                    // remove dhcp conf for selected interface
-                    $dhcp_cfg = file_get_contents(RASPI_DHCPCD_CONFIG);
-                    // todo: improve by removing extra blank lines
-                    $dhcp_cfg = preg_replace('/^#\sRaspAP\s'.$iface.'.*\n(.*\n){3}/m', '', $dhcp_cfg);
-                    file_put_contents("/tmp/dhcpddata", $dhcp_cfg);
-                    system('sudo cp /tmp/dhcpddata '.RASPI_DHCPCD_CONFIG, $return);
-                    $status->addMessage('DHCP configuration for '.$iface.'  removed.', 'success');
-                    // remove dnsmasq eth0 conf
-                    system('sudo rm '.RASPI_DNSMASQ_PREFIX.$iface.'.conf', $return);
-                    $status->addMessage('Dnsmasq configuration for '.$iface.' removed.', 'success');
-                } else {
-                    system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_CONFIG, $return);
-                }
-
-            } else {
-                $status->addMessage($errors, 'danger');
-            }
-
-            if ($return == 0) {
-                $status->addMessage('Dnsmasq configuration updated successfully.', 'success');
-            } else {
-                $status->addMessage('Dnsmasq configuration failed to be updated.', 'danger');
-            }
+            SaveDHCPConfig($status);
         }
     }
-
     exec('pidof dnsmasq | wc -l', $dnsmasq);
     $dnsmasq_state = ($dnsmasq[0] > 0);
 
@@ -191,3 +61,143 @@ function DisplayDHCPConfig()
         )
     );
 }
+
+function SaveDHCPConfig($status)
+{
+    $iface = $_POST['interface'];
+    $return = 1;
+
+    if (($_POST['dhcp-iface'] == "1")) {
+       $errors = ValidateDHCPInput();
+        if (empty($errors)) {
+            $config = 'interface='.$iface.PHP_EOL.
+                'dhcp-range='.$_POST['RangeStart'].','.$_POST['RangeEnd'].
+                ',255.255.255.0,';
+            if ($_POST['RangeLeaseTimeUnits'] !== 'infinite') {
+                $config .= $_POST['RangeLeaseTime'];
+            }
+            $config .= $_POST['RangeLeaseTimeUnits'].PHP_EOL;
+            for ($i=0; $i < count($_POST["static_leases"]["mac"]); $i++) {
+                $mac = trim($_POST["static_leases"]["mac"][$i]);
+                $ip  = trim($_POST["static_leases"]["ip"][$i]);
+                if ($mac != "" && $ip != "") {
+                    $config .= "dhcp-host=$mac,$ip".PHP_EOL;
+                }
+            }
+            if ($_POST['no-resolv'] == "1") {
+                $config .= "no-resolv".PHP_EOL;
+            }
+            foreach ($_POST['server'] as $server) {
+                $config .= "server=$server".PHP_EOL;
+            }
+            if ($_POST['log-dhcp'] == "1") {
+              $config .= "log-dhcp".PHP_EOL;
+            }
+            if ($_POST['log-queries'] == "1") {
+              $config .= "log-queries".PHP_EOL;
+            }
+            if ($_POST['DNS1']) {
+                $config .= "dhcp-option=6," . $_POST['DNS1'];
+                if ($_POST['DNS2']) {
+                    $config .= ','.$_POST['DNS2'];
+                }
+                $config .= PHP_EOL;
+            }
+            $config .= "log-facility=/tmp/dnsmasq.log".PHP_EOL;
+            $config .= "conf-dir=/etc/dnsmasq.d".PHP_EOL;
+            file_put_contents("/tmp/dnsmasqdata", $config);
+            $msg = file_exists(RASPI_DNSMASQ_PREFIX.$iface.'.conf') ? 'updated' : 'added';
+            system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_PREFIX.$iface.'.conf', $return);
+        } else {
+            $status->addMessage($errors, 'danger');
+        }
+
+        if ($return == 0) {
+            $status->addMessage('Dnsmasq configuration for '.$iface.' '.$msg.'.', 'success');
+        } else {
+            $status->addMessage('Dnsmasq configuration failed to be updated.', 'danger');
+            return false;
+        }
+
+        $net_cfg = RASPI_CONFIG_NETWORKING.'/'.$iface.'.ini';
+        if (!file_exists($net_cfg) || filesize($net_cfg) ==0 ) {
+            $status->addMessage('Static IP address for '.$iface.' not found.', 'danger');
+            $status->addMessage('Configure this interface in Networking > '.$iface.'.', 'danger');
+            $return = 1;
+        } else {
+            $dhcp_cfg = file_get_contents(RASPI_DHCPCD_CONFIG);
+            if (!preg_match('/^interface\s'.$iface.'$/m', $dhcp_cfg)) {
+                // set dhcp values from ini
+                $iface_cfg = parse_ini_file($net_cfg, false, INI_SCANNER_RAW);
+                $ip_address = $iface_cfg['ip_address'];
+                $domain_name_server = ($iface_cfg['domain_name_server'] =='') ? '1.1.1.1 8.8.8.8' : $iface_cfg['domain_name_server'];
+
+                // append interface config to dhcpcd.conf
+                $cfg = $dhcp_conf;
+                $cfg[] = '# RaspAP '.$_POST['interface'].' configuration';
+                $cfg[] = 'interface '.$_POST['interface'];
+                $cfg[] = 'static ip_address='.$ip_address;
+                $cfg[] = 'static domain_name_server='.$domain_name_server;
+                $cfg[] = PHP_EOL;
+                $cfg = join(PHP_EOL, $cfg);
+                $dhcp_cfg .= $cfg;
+                file_put_contents("/tmp/dhcpddata", $dhcp_cfg);
+                system('sudo cp /tmp/dhcpddata '.RASPI_DHCPCD_CONFIG, $return);
+                $status->addMessage('DHCP configuration for '.$iface.' added.', 'success');
+            } else {
+                $status->addMessage('DHCP for '.$iface.' already enabled.', 'success');
+            }
+        }
+    // process disable dhcp option
+    } elseif (($_POST['dhcp-iface'] == "0") && file_exists(RASPI_DNSMASQ_PREFIX.$iface.'.conf')) {
+        // remove dhcp conf for selected interface
+        $dhcp_cfg = file_get_contents(RASPI_DHCPCD_CONFIG);
+        // todo: improve by removing extra blank lines
+        $dhcp_cfg = preg_replace('/^#\sRaspAP\s'.$iface.'.*\n(.*\n){3}/m', '', $dhcp_cfg);
+        file_put_contents("/tmp/dhcpddata", $dhcp_cfg);
+        system('sudo cp /tmp/dhcpddata '.RASPI_DHCPCD_CONFIG, $return);
+        $status->addMessage('DHCP configuration for '.$iface.'  removed.', 'success');
+        // remove dnsmasq eth0 conf
+        system('sudo rm '.RASPI_DNSMASQ_PREFIX.$iface.'.conf', $return);
+        $status->addMessage('Dnsmasq configuration for '.$iface.' removed.', 'success');
+    } else {
+        system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_PREFIX.$iface.'.conf', $return);
+    }
+
+    if ($return == 0) {
+        $status->addMessage('Dnsmasq configuration updated successfully.', 'success');
+    } else {
+        $status->addMessage('Dnsmasq configuration failed to be updated.', 'danger');
+        return false;
+    }
+    return true;
+}
+
+function ValidateDHCPInput()
+{
+    define('IFNAMSIZ', 16);
+    $iface = $_POST['interface'];
+    if (!preg_match('/^[a-zA-Z0-9]+$/', $iface)
+        || strlen($iface) >= IFNAMSIZ
+    ) {
+        $errors .= _('Invalid interface name.').'<br />'.PHP_EOL;
+    }
+    if (!preg_match('/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\z/', $_POST['RangeStart'])
+        && !empty($_POST['RangeStart'])
+    ) {  // allow ''/null ?
+        $errors .= _('Invalid DHCP range start.').'<br />'.PHP_EOL;
+    }
+    if (!preg_match('/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\z/', $_POST['RangeEnd'])
+        && !empty($_POST['RangeEnd'])
+    ) {  // allow ''/null ?
+        $errors .= _('Invalid DHCP range end.').'<br />'.PHP_EOL;
+    }
+    if (!ctype_digit($_POST['RangeLeaseTime']) && $_POST['RangeLeaseTimeUnits'] !== 'infinite') {
+        $errors .= _('Invalid DHCP lease time, not a number.').'<br />'.PHP_EOL;
+    }
+    if (!in_array($_POST['RangeLeaseTimeUnits'], array('m', 'h', 'd', 'infinite'))) {
+        $errors .= _('Unknown DHCP lease time unit.').'<br />'.PHP_EOL;
+    }
+    return $errors;
+}
+