diff --git a/includes/discovery/os/datacom.inc.php b/includes/discovery/os/datacom.inc.php
index 53a566e70d..12239ec4e9 100644
--- a/includes/discovery/os/datacom.inc.php
+++ b/includes/discovery/os/datacom.inc.php
@@ -1,6 +1,5 @@
 <?php
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.3709')) {
-        $os = 'datacom';
-    }
+
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.3709')) {
+    $os = 'datacom';
 }
diff --git a/includes/discovery/os/datadomain.inc.php b/includes/discovery/os/datadomain.inc.php
index 5382b47c27..a2ff81693d 100644
--- a/includes/discovery/os/datadomain.inc.php
+++ b/includes/discovery/os/datadomain.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.19746.3.1')) {
-        $os = 'datadomain';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.19746.3.1')) {
+    $os = 'datadomain';
 }
diff --git a/includes/discovery/os/deliberant.inc.php b/includes/discovery/os/deliberant.inc.php
index 91884ca63b..f9c3d3d55f 100644
--- a/includes/discovery/os/deliberant.inc.php
+++ b/includes/discovery/os/deliberant.inc.php
@@ -9,8 +9,7 @@
  * option) any later version.  Please see LICENSE.txt at the top level of
  * the source code distribution for details.
  */
-if (!$os) {
-    if (strstr($sysDescr, 'Deliberant')) {
-        $os = 'deliberant';
-    }
+
+if (str_contains($sysDescr, 'Deliberant')) {
+    $os = 'deliberant';
 }
diff --git a/includes/discovery/os/dell-laser.inc.php b/includes/discovery/os/dell-laser.inc.php
index 030ae8a944..1425dd7944 100644
--- a/includes/discovery/os/dell-laser.inc.php
+++ b/includes/discovery/os/dell-laser.inc.php
@@ -1,13 +1,7 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysDescr, 'Dell Color Laser')) {
+if (str_contains($sysDescr, array('Dell Color Laser', 'Dell Laser Printer'))) {
         $os = 'dell-laser';
-    }
-    if (strstr($sysDescr, 'Dell Laser Printer')) {
+} elseif (preg_match('/^Dell.*MFP/', $sysDescr)) {
         $os = 'dell-laser';
-    }
-    if (preg_match('/^Dell.*MFP/', $sysDescr)) {
-        $os = 'dell-laser';
-    }
 }
diff --git a/includes/discovery/os/deltaups.inc.php b/includes/discovery/os/deltaups.inc.php
index 0df9ffb7d0..8d8d914308 100644
--- a/includes/discovery/os/deltaups.inc.php
+++ b/includes/discovery/os/deltaups.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.2254.2.4')) {
-        $os = 'deltaups';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.2254.2.4')) {
+    $os = 'deltaups';
 }
diff --git a/includes/discovery/os/developprinter.inc.php b/includes/discovery/os/developprinter.inc.php
index 5cddcb0ff0..f93e2a2911 100644
--- a/includes/discovery/os/developprinter.inc.php
+++ b/includes/discovery/os/developprinter.inc.php
@@ -9,8 +9,7 @@
  * option) any later version.  Please see LICENSE.txt at the top level of
  * the source code distribution for details.
  */
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.18334.1.2.1.2.1.50.2.2')) {
-        $os = 'developprinter';
-    }
+
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.18334.1.2.1.2.1.50.2.2')) {
+    $os = 'developprinter';
 }
diff --git a/includes/discovery/os/dlink.inc.php b/includes/discovery/os/dlink.inc.php
index 313158ee1c..731c80b8d2 100644
--- a/includes/discovery/os/dlink.inc.php
+++ b/includes/discovery/os/dlink.inc.php
@@ -1,16 +1,7 @@
 <?php
 
-if (!$os) {
-    if (preg_match('/D-Link DES-/', $sysDescr)) {
-        $os = 'dlink';
-    }
-    if (preg_match('/Dlink DES-/', $sysDescr)) {
-        $os = 'dlink';
-    }
-    if (preg_match('/^DES-/', $sysDescr)) {
-        $os = 'dlink';
-    }
-    if (preg_match('/^DGS-/', $sysDescr)) {
-        $os = 'dlink';
-    }
+if (str_contains($sysDescr, array('D-Link DES-', 'Dlink DES-'))) {
+    $os = 'dlink';
+} elseif (starts_with($sysDescr, array('DES-', 'DGS-'))) {
+    $os = 'dlink';
 }
diff --git a/includes/discovery/os/dlinkap.inc.php b/includes/discovery/os/dlinkap.inc.php
index 3cd1d71799..477fcc68b1 100644
--- a/includes/discovery/os/dlinkap.inc.php
+++ b/includes/discovery/os/dlinkap.inc.php
@@ -1,13 +1,7 @@
 <?php
 
-if (!$os) {
-    if (preg_match('/D-Link .* AP/', $sysDescr)) {
-        $os = 'dlinkap';
-    }
-    if (preg_match('/D-Link DAP-/', $sysDescr)) {
-        $os = 'dlinkap';
-    }
-    if (preg_match('/D-Link Access Point/', $sysDescr)) {
-        $os = 'dlinkap';
-    }
+if (preg_match('/D-Link .* AP/', $sysDescr)) {
+    $os = 'dlinkap';
+} elseif (str_contains($sysDescr, array('D-Link DAP-', 'D-Link Access Point'))) {
+    $os = 'dlinkap';
 }
diff --git a/includes/discovery/os/dnos.inc.php b/includes/discovery/os/dnos.inc.php
index 8901bbae9d..539ffa59e3 100644
--- a/includes/discovery/os/dnos.inc.php
+++ b/includes/discovery/os/dnos.inc.php
@@ -1,40 +1,20 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.6027.1.')) {
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3042')) {
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3044')) {
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3054')) {
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3055')) {
-        //Dell N2024P
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3056')) {
-        //Dell N2048P
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3046')) {
-        //Dell N4064F
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3057')) {
-        //Dell N3024
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3058')) {
-        //Dell N3048P
-        $os = 'dnos';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.674.10895.3060')) {
-        //Dell N3024P
-        $os = 'dnos';
-    }
+$dnos_objectid = array(
+    '.1.3.6.1.4.1.6027.1.',
+    '.1.3.6.1.4.1.674.10895.3042',
+    '.1.3.6.1.4.1.674.10895.3044',
+    '.1.3.6.1.4.1.674.10895.3054',
+    '.1.3.6.1.4.1.674.10895.3055',
+    '.1.3.6.1.4.1.674.10895.3056',
+    '.1.3.6.1.4.1.674.10895.3046',
+    '.1.3.6.1.4.1.674.10895.3057',
+    '.1.3.6.1.4.1.674.10895.3058',
+    '.1.3.6.1.4.1.674.10895.3060',
+);
+
+if (starts_with($sysObjectId, $dnos_objectid)) {
+    $os = 'dnos';
 }
+
+unset($dnos_objectid);
diff --git a/includes/discovery/os/drac.inc.php b/includes/discovery/os/drac.inc.php
index b049c9930a..b4d0039b8a 100644
--- a/includes/discovery/os/drac.inc.php
+++ b/includes/discovery/os/drac.inc.php
@@ -1,9 +1,8 @@
 <?php
 
-if (!$os) {
-    // DRAC5, iDRAC6  - 1.3.6.1.4.1.674.10892.2
-    // iDRAC7, iDRAC8 - 1.3.6.1.4.1.674.10892.5
-    if (strstr($sysDescr, 'Dell Out-of-band SNMP Agent for Remote Access Controller') || strstr($sysObjectId, '1.3.6.1.4.1.674.10892.2') || strstr($sysObjectId, '1.3.6.1.4.1.674.10892.5')) {
-        $os = 'drac';
-    }
+// DRAC5, iDRAC6  - 1.3.6.1.4.1.674.10892.2
+// iDRAC7, iDRAC8 - 1.3.6.1.4.1.674.10892.5
+if (str_contains($sysDescr, 'Dell Out-of-band SNMP Agent for Remote Access Controller') ||
+    starts_with($sysObjectId, array('.1.3.6.1.4.1.674.10892.2', '.1.3.6.1.4.1.674.10892.5'))) {
+    $os = 'drac';
 }
diff --git a/includes/discovery/os/eatonpdu.inc.php b/includes/discovery/os/eatonpdu.inc.php
index 8445e1817d..8f72b41f46 100644
--- a/includes/discovery/os/eatonpdu.inc.php
+++ b/includes/discovery/os/eatonpdu.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.534.6.6.7')) {
-        $os = 'eatonpdu';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.534.6.6.7')) {
+    $os = 'eatonpdu';
 }
diff --git a/includes/discovery/os/edgeswitch.inc.php b/includes/discovery/os/edgeswitch.inc.php
index 7595079ceb..55071b9348 100644
--- a/includes/discovery/os/edgeswitch.inc.php
+++ b/includes/discovery/os/edgeswitch.inc.php
@@ -1,6 +1,5 @@
 <?php
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.4413') && (!stristr($sysDescr, 'vxworks') && !stristr($sysDescr, 'Quanta') && !stristr($sysDescr, 'FASTPATH Switching'))) {
-        $os = 'edgeswitch';
-    }
+
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.4413') && !str_contains($sysDescr, array('vxworks', 'Quanta', 'FASTPATH Switching'), true)) {
+    $os = 'edgeswitch';
 }
diff --git a/includes/discovery/os/engenius.inc.php b/includes/discovery/os/engenius.inc.php
index a9a6397b7e..0ff4017eca 100644
--- a/includes/discovery/os/engenius.inc.php
+++ b/includes/discovery/os/engenius.inc.php
@@ -1,15 +1,11 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.14125.100.1.3')) {
+if (starts_with($sysObjectId, array('.1.3.6.1.4.1.14125.100.1.3', '.1.3.6.1.4.1.14125.101.1.3'))) {
+    $os = 'engenius';
+} elseif (starts_with($sysDescr, 'Wireless Access Point')) {
+    // a little more description about what this does would be nice... ;-)
+    $engenius_snmpget = snmp_get($device, 'SNMPv2-SMI::enterprises.14125.2.1.1.6.0', '-Oqv', '');
+    if (!empty($engenius_snmpget)) {
         $os = 'engenius';
-    } elseif (strstr($sysObjectId, '.1.3.6.1.4.1.14125.101.1.3')) {
-        $os = 'engenius';
-    } elseif ($sysDescr == 'Wireless Access Point') {
-        // a little more description about what this does would be nice... ;-)
-        $engenius_snmpget = snmp_get($device, 'SNMPv2-SMI::enterprises.14125.2.1.1.6.0', '-Oqv', '');
-        if (!empty($engenius_snmpget)) {
-            $os = 'engenius';
-        }
     }
 }
diff --git a/includes/discovery/os/enterasys.inc.php b/includes/discovery/os/enterasys.inc.php
index a7ec90ceec..bc5d68058d 100644
--- a/includes/discovery/os/enterasys.inc.php
+++ b/includes/discovery/os/enterasys.inc.php
@@ -1,10 +1,7 @@
 <?php
 
-if (!$os) {
-    if (preg_match('/^Enterasys Networks/', $sysDescr)) {
-        $os = 'enterasys';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.5624.2.1')) {
-        $os = 'enterasys';
-    }
+if (starts_with($sysDescr, 'Enterasys Networks')) {
+    $os = 'enterasys';
+} elseif (starts_with($sysObjectId, '.1.3.6.1.4.1.5624.2.1')) {
+    $os = 'enterasys';
 }
diff --git a/includes/discovery/os/epson.inc.php b/includes/discovery/os/epson.inc.php
index 52467ca2fe..164326f794 100644
--- a/includes/discovery/os/epson.inc.php
+++ b/includes/discovery/os/epson.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysDescr, 'EPSON Built-in')) {
-        $os = 'epson';
-    }
+if (str_contains($sysDescr, 'EPSON Built-in')) {
+    $os = 'epson';
 }
diff --git a/includes/discovery/os/equallogic.inc.php b/includes/discovery/os/equallogic.inc.php
index ed423792cd..b79cc7bb19 100644
--- a/includes/discovery/os/equallogic.inc.php
+++ b/includes/discovery/os/equallogic.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.12740.17.1')) {
-        $os = 'equallogic';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.12740.17.1')) {
+    $os = 'equallogic';
 }
diff --git a/includes/discovery/os/extremeware.inc.php b/includes/discovery/os/extremeware.inc.php
index b8d47304e3..ccaa74dc22 100644
--- a/includes/discovery/os/extremeware.inc.php
+++ b/includes/discovery/os/extremeware.inc.php
@@ -1,11 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.1916.2')) {
-        $os = 'extremeware';
-    }
-
-    if (strstr($sysDescr, 'XOS')) {
-        $os = 'xos';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.1916.2')) {
+    $os = 'extremeware';
 }
diff --git a/includes/discovery/os/fabos.inc.php b/includes/discovery/os/fabos.inc.php
index d7cec3fdf7..e6fc09432d 100644
--- a/includes/discovery/os/fabos.inc.php
+++ b/includes/discovery/os/fabos.inc.php
@@ -1,7 +1,13 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.1588.2.1.1.1') || strstr($sysObjectId, '.1.3.6.1.4.1.1588.2.1.1.43') || strstr($sysObjectId, '.1.3.6.1.4.1.1588.2.1.1.72')) {
-        $os = 'fabos';
-    }
+$fabos_objectid = array(
+    '.1.3.6.1.4.1.1588.2.1.1.1',
+    '.1.3.6.1.4.1.1588.2.1.1.43',
+    '.1.3.6.1.4.1.1588.2.1.1.72',
+);
+
+if (starts_with($sysObjectId, $fabos_objectid)) {
+    $os = 'fabos';
 }
+
+unset($fabos_objectid);
diff --git a/includes/discovery/os/fiberhome.inc.php b/includes/discovery/os/fiberhome.inc.php
index dfcce8b37a..af13708f74 100644
--- a/includes/discovery/os/fiberhome.inc.php
+++ b/includes/discovery/os/fiberhome.inc.php
@@ -1,11 +1,10 @@
 <?php
-if (!$os) {
-    /**
-     * Supported Devides List
-     * OLT AN5516-06
-     * OLT AN5516-01
-     */
-    if (preg_match('/^AN5516-0[16]$/', $sysDescr)) {
+
+/**
+ * Supported Devides List
+ * OLT AN5516-06
+ * OLT AN5516-01
+ */
+if (preg_match('/^AN5516-0[16]$/', $sysDescr)) {
         $os = "fiberhome";
-    }
 }
diff --git a/includes/discovery/os/fireware.inc.php b/includes/discovery/os/fireware.inc.php
index 3bb2a6693b..42c45d6d44 100644
--- a/includes/discovery/os/fireware.inc.php
+++ b/includes/discovery/os/fireware.inc.php
@@ -1,5 +1,4 @@
 <?php
-
 /*
  * LibreNMS
  *
@@ -12,6 +11,6 @@
  * the source code distribution for details.
  */
 
-if (preg_match('/^(XTM|FBX)/i', $sysDescr)) {
+if (starts_with($sysDescr, array('XTM', 'FBX'), true)) {
     $os = 'fireware';
 }
diff --git a/includes/discovery/os/flareos.inc.php b/includes/discovery/os/flareos.inc.php
index 5d99c03443..9df430f2f0 100644
--- a/includes/discovery/os/flareos.inc.php
+++ b/includes/discovery/os/flareos.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.1981.1.1')) {
-        $os = 'flareos';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.1981.1.1')) {
+    $os = 'flareos';
 }
diff --git a/includes/discovery/os/fortigate.inc.php b/includes/discovery/os/fortigate.inc.php
index 03c988cd36..7096566f4f 100644
--- a/includes/discovery/os/fortigate.inc.php
+++ b/includes/discovery/os/fortigate.inc.php
@@ -1,11 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.12356.15')) {
+if (starts_with($sysObjectId, array('.1.3.6.1.4.1.12356.15', '.1.3.6.1.4.1.12356.101.1'))) {
         $os = 'fortigate';
-    }
-
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.12356.101.1')) {
-        $os = 'fortigate';
-    }
 }
diff --git a/includes/discovery/os/fortios.inc.php b/includes/discovery/os/fortios.inc.php
index d5138abe1b..ee470ab929 100644
--- a/includes/discovery/os/fortios.inc.php
+++ b/includes/discovery/os/fortios.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.12356.103')) {
-        $os = 'fortios';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.12356.103')) {
+    $os = 'fortios';
 }
diff --git a/includes/discovery/os/foundryos.inc.php b/includes/discovery/os/foundryos.inc.php
index 9bdc542696..45665a3b9c 100644
--- a/includes/discovery/os/foundryos.inc.php
+++ b/includes/discovery/os/foundryos.inc.php
@@ -9,9 +9,7 @@
  * option) any later version.  Please see LICENSE.txt at the top level of
  * the source code distribution for details.
  */
- 
-if (!$os) {
-    if (str_contains($sysDescr, 'Foundry Networks')) {
-        $os = 'foundryos';
-    }
+
+if (str_contains($sysDescr, 'Foundry Networks')) {
+    $os = 'foundryos';
 }
diff --git a/includes/discovery/os/freebsd.inc.php b/includes/discovery/os/freebsd.inc.php
index 62e00ef379..4167ce31be 100644
--- a/includes/discovery/os/freebsd.inc.php
+++ b/includes/discovery/os/freebsd.inc.php
@@ -1,15 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysDescr, 'Voswall')) {
-        $os = 'voswall';
-    } //end if
-    elseif (strstr($sysDescr, 'm0n0wall')) {
-        $os = 'monowall';
-    } // Ditto
-    elseif (strstr($sysDescr, 'pfSense')) {
-        $os = 'pfsense';
-    } elseif (strstr($sysDescr, 'FreeBSD')) {
-        $os = 'freebsd';
-    } // It's FreeBSD!
+if (str_contains($sysDescr, 'FreeBSD')) {
+    $os = 'freebsd';
 }
diff --git a/includes/discovery/os/ftos.inc.php b/includes/discovery/os/ftos.inc.php
index aae6334653..eb55e46be4 100644
--- a/includes/discovery/os/ftos.inc.php
+++ b/includes/discovery/os/ftos.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysDescr, 'Force10 Operating System')) {
-        $os = 'ftos';
-    }
+if (str_contains($sysDescr, 'Force10 Operating System')) {
+    $os = 'ftos';
 }
diff --git a/includes/discovery/os/fujitsupyos.inc.php b/includes/discovery/os/fujitsupyos.inc.php
index 65e30c0f9b..6cc621f4d6 100644
--- a/includes/discovery/os/fujitsupyos.inc.php
+++ b/includes/discovery/os/fujitsupyos.inc.php
@@ -9,9 +9,7 @@
  * option) any later version.  Please see LICENSE.txt at the top level of
  * the source code distribution for details.
  */
- 
-if (!$os) {
-    if (stristr($sysDescr, 'Fujitsu PY CB Eth Switch')) {
-        $os = 'fujitsupyos';
-    }
+
+if (str_contains($sysDescr, 'Fujitsu PY CB Eth Switch', true)) {
+    $os = 'fujitsupyos';
 }
diff --git a/includes/discovery/os/fxos.inc.php b/includes/discovery/os/fxos.inc.php
index 75be69fd17..8734a5e227 100644
--- a/includes/discovery/os/fxos.inc.php
+++ b/includes/discovery/os/fxos.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (empty($os)) {
-    if (strstr($sysDescr, 'Cisco FX-OS')) {
-        $os = 'fxos';
-    }
+if (str_contains($sysDescr, 'Cisco FX-OS')) {
+    $os = 'fxos';
 }
diff --git a/includes/discovery/os/gamatronicups.inc.php b/includes/discovery/os/gamatronicups.inc.php
index 8ddc691a3a..f38f0f238d 100644
--- a/includes/discovery/os/gamatronicups.inc.php
+++ b/includes/discovery/os/gamatronicups.inc.php
@@ -1,9 +1,7 @@
 <?php
 
-if (!$os) {
-    if ($sysDescr == '') {
-        if (snmp_get($device, 'GAMATRONIC-MIB::psUnitManufacture.0', '-Oqv', '') == 'Gamatronic') {
-            $os = 'gamatronicups';
-        }
+if (empty($sysDescr)) {
+    if (snmp_get($device, 'GAMATRONIC-MIB::psUnitManufacture.0', '-Oqv', '') == 'Gamatronic') {
+        $os = 'gamatronicups';
     }
 }
diff --git a/includes/discovery/os/hikvision.inc.php b/includes/discovery/os/hikvision.inc.php
index dbb44eff38..0caa79cd05 100644
--- a/includes/discovery/os/hikvision.inc.php
+++ b/includes/discovery/os/hikvision.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (preg_match('/Hikvision/', snmp_get($device, '.1.3.6.1.4.1.39165.1.6.0', '-Oqv', ''))) {
-        $os = 'hikvision';
-    }
+if (str_contains(snmp_get($device, '.1.3.6.1.4.1.39165.1.6.0', '-Oqv', ''), 'Hikvision')) {
+    $os = 'hikvision';
 }
diff --git a/includes/discovery/os/hpblmos.inc.php b/includes/discovery/os/hpblmos.inc.php
index 9eba8faa5c..d0749e3ff6 100644
--- a/includes/discovery/os/hpblmos.inc.php
+++ b/includes/discovery/os/hpblmos.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.11.5.7.1.2')) {
-        $os = 'hpblmos';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.11.5.7.1.2')) {
+    $os = 'hpblmos';
 }
diff --git a/includes/discovery/os/hpmsm.inc.php b/includes/discovery/os/hpmsm.inc.php
index 29a8d8499e..bc420e8cb8 100644
--- a/includes/discovery/os/hpmsm.inc.php
+++ b/includes/discovery/os/hpmsm.inc.php
@@ -9,12 +9,11 @@
  * option) any later version.  Please see LICENSE.txt at the top level of
  * the source code distribution for details.
  */
-if (!$os) {
-    if (strpos($sysObjectId, '1.3.6.1.4.1.8744.1') !== false) {
-        $split_oid = explode('.', $sysObjectId);
-        $model_oid = $split_oid[count($split_oid)-1];
-        if ($model_oid >= 40 && $model_oid < 60 || $model_oid = 67) {
-            $os = 'hpmsm';
-        }
+
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.8744.1')) {
+    $split_oid = explode('.', $sysObjectId);
+    $model_oid = $split_oid[count($split_oid)-1];
+    if ($model_oid >= 40 && $model_oid < 60 || $model_oid = 67) {
+        $os = 'hpmsm';
     }
 }
diff --git a/includes/discovery/os/hpvc.inc.php b/includes/discovery/os/hpvc.inc.php
index 86f0aacd85..5a8959b4b2 100644
--- a/includes/discovery/os/hpvc.inc.php
+++ b/includes/discovery/os/hpvc.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.11.5.7.5.1')) {
-        $os = 'hpvc';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.11.5.7.5.1')) {
+    $os = 'hpvc';
 }
diff --git a/includes/discovery/os/huaweiups.inc.php b/includes/discovery/os/huaweiups.inc.php
index a2efc21d5a..81823210f4 100644
--- a/includes/discovery/os/huaweiups.inc.php
+++ b/includes/discovery/os/huaweiups.inc.php
@@ -1,9 +1,7 @@
 <?php
 
-if (!$os) {
-    if (preg_match('/^Linux GSE200M/', $sysDescr)) {
-        if (strstr(snmp_get($device, 'UPS-MIB::upsIdentManufacturer.0', '-Oqv', ''), 'HUAWEI')) {
-            $os = 'huaweiups';
-        }
+if (starts_with($sysDescr, 'Linux GSE200M')) {
+    if (str_contains(snmp_get($device, 'UPS-MIB::upsIdentManufacturer.0', '-Oqv', ''), 'HUAWEI')) {
+        $os = 'huaweiups';
     }
 }
diff --git a/includes/discovery/os/hwg-poseidon.inc.php b/includes/discovery/os/hwg-poseidon.inc.php
index 6bbd82aca5..a49a9d2e6d 100644
--- a/includes/discovery/os/hwg-poseidon.inc.php
+++ b/includes/discovery/os/hwg-poseidon.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.21796.3.3')) {
-        $os = 'hwg-poseidon';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.21796.3.3')) {
+    $os = 'hwg-poseidon';
 }
diff --git a/includes/discovery/os/hwg-ste.inc.php b/includes/discovery/os/hwg-ste.inc.php
index 67ea3da6a2..86716f93de 100644
--- a/includes/discovery/os/hwg-ste.inc.php
+++ b/includes/discovery/os/hwg-ste.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.21796.4.1')) {
-        $os = 'hwg-ste';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.21796.4.1')) {
+    $os = 'hwg-ste';
 }
diff --git a/includes/discovery/os/hwg-ste2.inc.php b/includes/discovery/os/hwg-ste2.inc.php
index efcd711139..93a9aa7317 100644
--- a/includes/discovery/os/hwg-ste2.inc.php
+++ b/includes/discovery/os/hwg-ste2.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.21796.4.9')) {
-        $os = 'hwg-ste2';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.21796.4.9')) {
+    $os = 'hwg-ste2';
 }
diff --git a/includes/discovery/os/hytera.inc.php b/includes/discovery/os/hytera.inc.php
index db54d5b0b4..444157d25e 100644
--- a/includes/discovery/os/hytera.inc.php
+++ b/includes/discovery/os/hytera.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.26381')) {
-        $os = "hytera";
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.26381')) {
+    $os = "hytera";
 }
diff --git a/includes/discovery/os/hp3par.inc.php b/includes/discovery/os/informos.inc.php
similarity index 81%
rename from includes/discovery/os/hp3par.inc.php
rename to includes/discovery/os/informos.inc.php
index e0325b19f8..772fb813d0 100644
--- a/includes/discovery/os/hp3par.inc.php
+++ b/includes/discovery/os/informos.inc.php
@@ -10,8 +10,6 @@
  * the source code distribution for details.
  */
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.12925.1')) {
-        $os = 'informos';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.12925.1')) {
+    $os = 'informos';
 }
diff --git a/includes/discovery/os/monowall.inc.php b/includes/discovery/os/monowall.inc.php
new file mode 100644
index 0000000000..7bf5a401f1
--- /dev/null
+++ b/includes/discovery/os/monowall.inc.php
@@ -0,0 +1,5 @@
+<?php
+
+if (str_contains($sysDescr, 'm0n0wall')) {
+    $os = 'monowall';
+}
diff --git a/includes/discovery/os/pfsense.inc.php b/includes/discovery/os/pfsense.inc.php
new file mode 100644
index 0000000000..e0a31e931f
--- /dev/null
+++ b/includes/discovery/os/pfsense.inc.php
@@ -0,0 +1,5 @@
+<?php
+
+if (str_contains($sysDescr, 'pfSense')) {
+    $os = 'pfsense';
+}
diff --git a/includes/discovery/os/voswall.inc.php b/includes/discovery/os/voswall.inc.php
new file mode 100644
index 0000000000..2697ea94c2
--- /dev/null
+++ b/includes/discovery/os/voswall.inc.php
@@ -0,0 +1,5 @@
+<?php
+
+if (str_contains($sysDescr, 'Voswall')) {
+    $os = 'voswall';
+}
diff --git a/includes/discovery/os/xos.inc.php b/includes/discovery/os/xos.inc.php
new file mode 100644
index 0000000000..71f3cf3ce9
--- /dev/null
+++ b/includes/discovery/os/xos.inc.php
@@ -0,0 +1,5 @@
+<?php
+
+if (str_contains($sysDescr, 'XOS')) {
+    $os = 'xos';
+}