diff --git a/LibreNMS/Modules/Isis.php b/LibreNMS/Modules/Isis.php
index 27eca2b610..b11de878a8 100644
--- a/LibreNMS/Modules/Isis.php
+++ b/LibreNMS/Modules/Isis.php
@@ -180,7 +180,7 @@ class Isis implements Module
 
     protected function parseAdjacencyTime($data): int
     {
-        return (int) max($data['isisISAdjLastUpTime'] ?? 1, 1) / 100;
+        return (int) (max($data['isisISAdjLastUpTime'] ?? 1, 1) / 100);
     }
 
     /**
diff --git a/LibreNMS/OS/ArubaInstant.php b/LibreNMS/OS/ArubaInstant.php
index 4499612cff..6047c7b1c9 100644
--- a/LibreNMS/OS/ArubaInstant.php
+++ b/LibreNMS/OS/ArubaInstant.php
@@ -264,7 +264,10 @@ class ArubaInstant extends OS implements
 
     protected function decodeChannel($channel): int
     {
-        return cast_number($channel) & 255; // mask off the channel width information
+        // Trim off everything not a digit, like channel "116e"
+        $channel = preg_replace("/\D/", '', $channel);
+
+        return $channel & 255; // mask off the channel width information
     }
 
     /**
diff --git a/LibreNMS/OS/Ciscosb.php b/LibreNMS/OS/Ciscosb.php
index c00646fbaf..eeead4feab 100644
--- a/LibreNMS/OS/Ciscosb.php
+++ b/LibreNMS/OS/Ciscosb.php
@@ -62,6 +62,8 @@ class Ciscosb extends OS implements OSDiscovery
         if ($firmware) {
             $device->version .= ", Firmware $firmware";
         }
-        $device->version = trim($device->version, ', ');
+        if ($device->version) {
+            $device->version = trim($device->version, ', ');
+        }
     }
 }
diff --git a/LibreNMS/OS/Junose.php b/LibreNMS/OS/Junose.php
index 948462b1f8..f29e42551b 100644
--- a/LibreNMS/OS/Junose.php
+++ b/LibreNMS/OS/Junose.php
@@ -31,7 +31,7 @@ class Junose extends \LibreNMS\OS
 {
     public function discoverOS(Device $device): void
     {
-        if (strpos($device->sysDescr, 'olive')) {
+        if (is_string($device->sysDescr) && strpos($device->sysDescr, 'olive')) {
             $device->hardware = 'Olive';
 
             return;
diff --git a/LibreNMS/OS/Lcos.php b/LibreNMS/OS/Lcos.php
index 043862152b..30a7581339 100644
--- a/LibreNMS/OS/Lcos.php
+++ b/LibreNMS/OS/Lcos.php
@@ -226,7 +226,7 @@ class Lcos extends OS implements
                 'lcos',
                 $bssid,
                 'CCQ ' . $entry['lcsStatusWlanCompetingNetworksEntryInterpointPeerName'] . " $bssid",
-                $entry['lcsStatusWlanCompetingNetworksEntryPhySigal']
+                $entry['lcsStatusWlanCompetingNetworksEntryPhySignal']
             );
         }
 
diff --git a/LibreNMS/OS/Shared/Cisco.php b/LibreNMS/OS/Shared/Cisco.php
index c1ac8fdc4a..c5009037b1 100755
--- a/LibreNMS/OS/Shared/Cisco.php
+++ b/LibreNMS/OS/Shared/Cisco.php
@@ -118,7 +118,7 @@ class Cisco extends OS implements
             $hardware = $data[1000]['entPhysicalModelName'];
         } elseif (empty($hardware) && ! empty($data[1000]['entPhysicalContainedIn'])) {
             $hardware = $data[$data[1000]['entPhysicalContainedIn']]['entPhysicalName'];
-        } elseif ((preg_match('/stack/i', $hardware) || empty($hardware)) && ! empty($data[1001]['entPhysicalModelName'])) {
+        } elseif ((preg_match('/stack/i', $hardware ?? '') || empty($hardware)) && ! empty($data[1001]['entPhysicalModelName'])) {
             $hardware = $data[1001]['entPhysicalModelName'];
         } elseif (empty($hardware) && ! empty($data[1001]['entPhysicalContainedIn'])) {
             $hardware = $data[$data[1001]['entPhysicalContainedIn']]['entPhysicalName'];
@@ -294,7 +294,7 @@ class Cisco extends OS implements
              * Could be dynamically changed to appropriate value if config had pol interval value
              */
             $qfp_usage_oid = '.1.3.6.1.4.1.9.9.715.1.1.6.1.14.' . $entQfpPhysicalIndex . '.3';
-            $qfp_usage = $entry['fiveMinute'];
+            $qfp_usage = $entry['fiveMinute'] ?? null;
 
             if ($entQfpPhysicalIndex) {
                 $qfp_descr = $this->getCacheByIndex('entPhysicalName', 'ENTITY-MIB')[$entQfpPhysicalIndex];
diff --git a/LibreNMS/OS/Shared/Foundry.php b/LibreNMS/OS/Shared/Foundry.php
index b0450fbf30..b0be7f0774 100644
--- a/LibreNMS/OS/Shared/Foundry.php
+++ b/LibreNMS/OS/Shared/Foundry.php
@@ -61,8 +61,12 @@ class Foundry extends OS implements ProcessorDiscovery
                 continue;
             }
 
-            $module_description = $module_descriptions[$entry['snAgentCpuUtilSlotNum']];
-            [$module_description] = explode(' ', $module_description);
+            $module_description = null;
+            if (isset($module_descriptions[$entry['snAgentCpuUtilSlotNum']])) {
+                $module_description = $module_descriptions[$entry['snAgentCpuUtilSlotNum']];
+                [$module_description] = explode(' ', $module_description);
+            }
+
             $descr = "Slot {$entry['snAgentCpuUtilSlotNum']} $module_description [{$entry['snAgentCpuUtilSlotNum']}]";
 
             $processors[] = Processor::discover(
diff --git a/LibreNMS/OS/Traits/CiscoCellular.php b/LibreNMS/OS/Traits/CiscoCellular.php
index 45c2572133..b2292b226d 100644
--- a/LibreNMS/OS/Traits/CiscoCellular.php
+++ b/LibreNMS/OS/Traits/CiscoCellular.php
@@ -61,7 +61,7 @@ trait CiscoCellular
                 'ios',
                 $index,
                 'RSSI: ' . $this->profileApn($index),
-                $entry['c3gCurrentGsmRssi.1']
+                $entry['c3gCurrentGsmRssi']
             );
         }
 
@@ -87,7 +87,7 @@ trait CiscoCellular
                 'ios',
                 $index,
                 'SNR: ' . $this->profileApn($index),
-                $entry['cwceLteCurrSnr.1'],
+                $entry['cwceLteCurrSnr'],
                 1,
                 10
             );
@@ -115,7 +115,7 @@ trait CiscoCellular
                 'ios',
                 $index,
                 'RSRQ: ' . $this->profileApn($index),
-                $entry['cwceLteCurrRsrq.1'],
+                $entry['cwceLteCurrRsrq'],
                 1,
                 10
             );
@@ -143,7 +143,7 @@ trait CiscoCellular
                 'ios',
                 $index,
                 'RSRP: ' . $this->profileApn($index),
-                $entry['cwceLteCurrRsrp.1']
+                $entry['cwceLteCurrRsrp']
             );
         }
 
@@ -169,7 +169,7 @@ trait CiscoCellular
                 'ios',
                 $index,
                 'ChannelRx: ' . $this->profileApn($index),
-                $entry['c3gGsmChannelNumber.1']
+                $entry['c3gGsmChannelNumber']
             );
         }
 
@@ -195,7 +195,7 @@ trait CiscoCellular
                 'ios',
                 $index,
                 'Cell: ' . $this->profileApn($index),
-                $entry['c3gGsmCurrentCellId.1']
+                $entry['c3gGsmCurrentCellId']
             );
         }
 
diff --git a/includes/common.php b/includes/common.php
index b1af79c039..fadc37e513 100644
--- a/includes/common.php
+++ b/includes/common.php
@@ -636,7 +636,7 @@ function get_port_id($ports_mapped, $port, $port_association_mode)
     $maps = $ports_mapped['maps'];
 
     if (in_array($port_association_mode, ['ifIndex', 'ifName', 'ifDescr', 'ifAlias'])) {
-        $port_id = $maps[$port_association_mode][$port[$port_association_mode]];
+        $port_id = $maps[$port_association_mode][$port[$port_association_mode]] ?? null;
     }
 
     return $port_id;
diff --git a/includes/discovery/ports.inc.php b/includes/discovery/ports.inc.php
index 72fc729174..befbb5efdb 100644
--- a/includes/discovery/ports.inc.php
+++ b/includes/discovery/ports.inc.php
@@ -86,7 +86,7 @@ $default_port_group = Config::get('default_port_group');
 // New interface detection
 foreach ($port_stats as $ifIndex => $snmp_data) {
     $snmp_data['ifIndex'] = $ifIndex; // Store ifIndex in port entry
-    $snmp_data['ifAlias'] = StringHelpers::inferEncoding($snmp_data['ifAlias']);
+    $snmp_data['ifAlias'] = StringHelpers::inferEncoding($snmp_data['ifAlias'] ?? null);
 
     // Get port_id according to port_association_mode used for this device
     $port_id = get_port_id($ports_mapped, $snmp_data, $port_association_mode);
@@ -95,7 +95,7 @@ foreach ($port_stats as $ifIndex => $snmp_data) {
         port_fill_missing_and_trim($snmp_data, $device);
 
         // Port newly discovered?
-        if (! is_array($ports_db[$port_id])) {
+        if (! isset($ports_db[$port_id]) || ! is_array($ports_db[$port_id])) {
             $snmp_data['device_id'] = $device['device_id'];
             $port_id = dbInsert($snmp_data, 'ports');
 
@@ -121,7 +121,7 @@ foreach ($port_stats as $ifIndex => $snmp_data) {
         }
     } else {
         // Port vanished (mark as deleted)
-        if (is_array($ports_db[$port_id])) {
+        if (isset($ports_db[$port_id]) && is_array($ports_db[$port_id])) {
             if ($ports_db[$port_id]['deleted'] != 1) {
                 dbUpdate(['deleted' => 1], 'ports', '`port_id` = ?', [$port_id]);
                 $ports_db[$port_id]['deleted'] = 1;
diff --git a/includes/discovery/sensors/ber/infinera-groove.inc.php b/includes/discovery/sensors/ber/infinera-groove.inc.php
index b828c90143..1dd8c0230b 100644
--- a/includes/discovery/sensors/ber/infinera-groove.inc.php
+++ b/includes/discovery/sensors/ber/infinera-groove.inc.php
@@ -25,7 +25,7 @@
  * Modified for FEC, Magnus Bergroth
  */
 foreach ($pre_cache['infineragroove_portTable'] as $index => $data) {
-    if (is_numeric($data['ochOsPreFecBer']) && $data['ochOsPreFecBer'] > 0) {
+    if (isset($data['ochOsPreFecBer']) && is_numeric($data['ochOsPreFecBer']) && $data['ochOsPreFecBer'] > 0) {
         $descr = $data['portAlias'] . ' PreFecBer';
         $oid = '.1.3.6.1.4.1.42229.1.2.4.1.19.1.1.26.' . $index;
         $value = $data['ochOsPreFecBer'];
diff --git a/includes/discovery/sensors/chromatic_dispersion/infinera-groove.inc.php b/includes/discovery/sensors/chromatic_dispersion/infinera-groove.inc.php
index d86735ab72..909b5ac6b0 100644
--- a/includes/discovery/sensors/chromatic_dispersion/infinera-groove.inc.php
+++ b/includes/discovery/sensors/chromatic_dispersion/infinera-groove.inc.php
@@ -23,7 +23,7 @@
  * @author     Nick Hilliard <nick@foobar.org>
  */
 foreach ($pre_cache['infineragroove_portTable'] as $index => $data) {
-    if (is_numeric($data['ochOsCD']) && $data['ochOsCD'] != -99) {
+    if (isset($data['ochOsCD']) && is_numeric($data['ochOsCD']) && $data['ochOsCD'] != -99) {
         $descr = $data['portAlias'] . ' CD';
         $oid = '.1.3.6.1.4.1.42229.1.2.4.1.19.1.1.23.' . $index;
         $value = $data['ochOsCD'];
diff --git a/includes/discovery/sensors/cisco-entity-sensor.inc.php b/includes/discovery/sensors/cisco-entity-sensor.inc.php
index c4579ad13d..0619d65bc1 100644
--- a/includes/discovery/sensors/cisco-entity-sensor.inc.php
+++ b/includes/discovery/sensors/cisco-entity-sensor.inc.php
@@ -63,7 +63,7 @@ if ($device['os_group'] == 'cisco') {
                 }
 
                 // Set description based on measured entity if it exists
-                if (is_numeric($entry['entSensorMeasuredEntity']) && $entry['entSensorMeasuredEntity']) {
+                if (isset($entry['entSensorMeasuredEntity']) && is_numeric($entry['entSensorMeasuredEntity']) && $entry['entSensorMeasuredEntity']) {
                     $measured_descr = $entity_array[$entry['entSensorMeasuredEntity']]['entPhysicalName'];
                     if (! $measured_descr) {
                         $measured_descr = $entity_array[$entry['entSensorMeasuredEntity']]['entPhysicalDescr'];
@@ -136,7 +136,7 @@ if ($device['os_group'] == 'cisco') {
                 $warn_limit_low = null;
 
                 // Check thresholds for this entry (bit dirty, but it works!)
-                if (is_array($t_oids[$index])) {
+                if (isset($t_oids[$index]) && is_array($t_oids[$index])) {
                     foreach ($t_oids[$index] as $t_index => $key) {
                         // Skip invalid treshold values
                         if ($key['entSensorThresholdValue'] == '-32768') {
diff --git a/includes/discovery/sensors/count/cisco.inc.php b/includes/discovery/sensors/count/cisco.inc.php
index 724371a1bb..9ae11f3768 100644
--- a/includes/discovery/sensors/count/cisco.inc.php
+++ b/includes/discovery/sensors/count/cisco.inc.php
@@ -26,9 +26,10 @@ foreach ($tables as $tablevalue) {
     $state_name = $tablevalue['state_name'];
     foreach ($temp as $index => $entry) {
         //Discover Sensors
-        $descr = ucwords($temp[$index][$tablevalue['descr']]);
         if ($state_name == 'c3gGsmNumberOfNearbyCell' || $state_name == 'cwceLteCurrOperatingBand') {
             $descr = snmp_get($device, 'entPhysicalName.' . $index, '-Oqv', 'ENTITY-MIB') . ' - ' . $tablevalue['descr'];
+        } else {
+            $descr = ucwords($temp[$index][$tablevalue['descr']]);
         }
         discover_sensor($valid['sensor'], 'count', $device, $cur_oid . $index, $index, $state_name, $descr, 1, 1, null, null, null, null, $temp[$index][$tablevalue['state_name']], 'snmp', $index);
     }
diff --git a/includes/discovery/sensors/current/ciscosb.inc.php b/includes/discovery/sensors/current/ciscosb.inc.php
index d6206db7bc..f234e15563 100644
--- a/includes/discovery/sensors/current/ciscosb.inc.php
+++ b/includes/discovery/sensors/current/ciscosb.inc.php
@@ -16,14 +16,17 @@ $multiplier = 1;
 $divisor = 1000000;
 foreach ($pre_cache['ciscosb_rlPhyTestGetResult'] as $index => $ciscosb_data) {
     foreach ($ciscosb_data as $key => $value) {
+        if (! isset($value['rlPhyTestTableTransceiverTemp']) || $value['rlPhyTestTableTransceiverTemp'] == 0) {
+            continue;
+        }
         $oid = '.1.3.6.1.4.1.9.6.1.101.90.1.2.1.3.' . $index . '.7';
         $sensor_type = 'rlPhyTestTableTxBias';
         $port_descr = get_port_by_index_cache($device['device_id'], preg_replace('/^\d+\./', '', $index));
-        $descr = trim($port_descr['ifDescr'] . ' Bias Current');
+        $descr = trim(($port_descr['ifDescr'] ?? '') . ' Bias Current');
         $current = $value['rlPhyTestTableTxBias'] / $divisor;
         $entPhysicalIndex = $index;
         $entPhysicalIndex_measured = 'ports';
-        if (is_numeric($current) && ($value['rlPhyTestTableTransceiverTemp'] != 0)) {
+        if (is_numeric($current)) {
             discover_sensor($valid['sensor'], 'current', $device, $oid, $index, $sensor_type, $descr, $divisor, $multiplier, null, null, null, null, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
         }
     }
diff --git a/includes/discovery/sensors/current/comware.inc.php b/includes/discovery/sensors/current/comware.inc.php
index 1e61db7455..6bb930c8bd 100644
--- a/includes/discovery/sensors/current/comware.inc.php
+++ b/includes/discovery/sensors/current/comware.inc.php
@@ -18,6 +18,11 @@ $divisor = 100000;
 $divisor_alarm = 1000000;
 foreach ($pre_cache['comware_oids'] as $index => $entry) {
     if (is_numeric($entry['hh3cTransceiverBiasCurrent']) && $entry['hh3cTransceiverBiasCurrent'] != 2147483647 && isset($entry['hh3cTransceiverDiagnostic'])) {
+        $interface = get_port_by_index_cache($device['device_id'], $index);
+        if ($interface['ifAdminStatus'] != 'up') {
+            continue;
+        }
+
         $oid = '.1.3.6.1.4.1.25506.2.70.1.1.1.17.' . $index;
         $limit_low = $entry['hh3cTransceiverBiasLoAlarm'] / $divisor_alarm;
         $warn_limit_low = $entry['hh3cTransceiverBiasLoWarn'] / $divisor_alarm;
@@ -26,10 +31,8 @@ foreach ($pre_cache['comware_oids'] as $index => $entry) {
         $current = $entry['hh3cTransceiverBiasCurrent'] / $divisor;
         $entPhysicalIndex = $index;
         $entPhysicalIndex_measured = 'ports';
-        $interface = get_port_by_index_cache($device['device_id'], $index);
-        if ($interface['ifAdminStatus'] == 'up') {
-            $descr = makeshortif($interface['ifDescr']) . ' Bias Current';
-            discover_sensor($valid['sensor'], 'current', $device, $oid, 'bias-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
-        }
+
+        $descr = makeshortif($interface['ifDescr']) . ' Bias Current';
+        discover_sensor($valid['sensor'], 'current', $device, $oid, 'bias-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
     }
 }
diff --git a/includes/discovery/sensors/dbm/ciscosb.inc.php b/includes/discovery/sensors/dbm/ciscosb.inc.php
index 615ff61b99..cc54ec00fa 100644
--- a/includes/discovery/sensors/dbm/ciscosb.inc.php
+++ b/includes/discovery/sensors/dbm/ciscosb.inc.php
@@ -16,21 +16,21 @@ $multiplier = 1;
 $divisor = 1000;
 foreach ($pre_cache['ciscosb_rlPhyTestGetResult'] as $index => $ciscosb_data) {
     foreach ($ciscosb_data as $key => $value) {
-        if (is_numeric($value['rlPhyTestTableTxOutput']) && ($value['rlPhyTestTableRxOpticalPower'] != 0)) {
+        if (isset($value['rlPhyTestTableTxOutput']) && is_numeric($value['rlPhyTestTableTxOutput']) && ($value['rlPhyTestTableRxOpticalPower'] != 0)) {
             $oid = '.1.3.6.1.4.1.9.6.1.101.90.1.2.1.3.' . $index . '.8';
             $sensor_type = 'rlPhyTestTableTxOutput';
             $port_descr = get_port_by_index_cache($device['device_id'], preg_replace('/^\d+\./', '', $index));
-            $descr = trim($port_descr['ifDescr'] . ' Transmit Power');
+            $descr = trim(($port_descr['ifDescr'] ?? null) . ' Transmit Power');
             $dbm = $value['rlPhyTestTableTxOutput'] / $divisor;
             $entPhysicalIndex = $index;
             $entPhysicalIndex_measured = 'ports';
             discover_sensor($valid['sensor'], 'dbm', $device, $oid, 'tx-' . $index, $sensor_type, $descr, $divisor, $multiplier, null, null, null, null, $dbm, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
         }
-        if (is_numeric($value['rlPhyTestTableRxOpticalPower']) && ($value['rlPhyTestTableTxOutput'] != 0)) {
+        if (isset($value['rlPhyTestTableRxOpticalPower']) && is_numeric($value['rlPhyTestTableRxOpticalPower']) && ($value['rlPhyTestTableTxOutput'] != 0)) {
             $oid = '.1.3.6.1.4.1.9.6.1.101.90.1.2.1.3.' . $index . '.9';
             $sensor_type = 'rlPhyTestTableRxOpticalPower';
             $port_descr = get_port_by_index_cache($device['device_id'], preg_replace('/^\d+\./', '', $index));
-            $descr = trim($port_descr['ifDescr'] . ' Receive Power');
+            $descr = trim(($port_descr['ifDescr'] ?? null) . ' Receive Power');
             $dbm = $value['rlPhyTestTableRxOpticalPower'] / $divisor;
             $entPhysicalIndex = $index;
             $entPhysicalIndex_measured = 'ports';
diff --git a/includes/discovery/sensors/dbm/comware.inc.php b/includes/discovery/sensors/dbm/comware.inc.php
index 3ce5012239..f40fe1e7c7 100644
--- a/includes/discovery/sensors/dbm/comware.inc.php
+++ b/includes/discovery/sensors/dbm/comware.inc.php
@@ -17,6 +17,11 @@ $multiplier = 1;
 $divisor = 100;
 foreach ($pre_cache['comware_oids'] as $index => $entry) {
     if (is_numeric($entry['hh3cTransceiverCurRXPower']) && $entry['hh3cTransceiverCurRXPower'] != 2147483647 && isset($entry['hh3cTransceiverDiagnostic'])) {
+        $interface = get_port_by_index_cache($device['device_id'], $index);
+        if ($interface['ifAdminStatus'] != 'up') {
+            continue;
+        }
+
         $oid = '.1.3.6.1.4.1.25506.2.70.1.1.1.12.' . $index;
         $limit_low = round(uw_to_dbm($entry['hh3cTransceiverRcvPwrLoAlarm'] / 10), 2);
         $warn_limit_low = round(uw_to_dbm($entry['hh3cTransceiverRcvPwrLoWarn'] / 10), 2);
@@ -25,11 +30,8 @@ foreach ($pre_cache['comware_oids'] as $index => $entry) {
         $current = $entry['hh3cTransceiverCurRXPower'] / $divisor;
         $entPhysicalIndex = $index;
         $entPhysicalIndex_measured = 'ports';
-        $interface = get_port_by_index_cache($device['device_id'], $index);
-        if ($interface['ifAdminStatus'] == 'up') {
-            $descr = makeshortif($interface['ifDescr']) . ' Receive Power';
-            discover_sensor($valid['sensor'], 'dbm', $device, $oid, 'rx-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
-        }
+        $descr = makeshortif($interface['ifDescr']) . ' Receive Power';
+        discover_sensor($valid['sensor'], 'dbm', $device, $oid, 'rx-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
     }
 
     if (is_numeric($entry['hh3cTransceiverCurTXPower']) && $entry['hh3cTransceiverCurTXPower'] != 2147483647 && isset($entry['hh3cTransceiverDiagnostic'])) {
diff --git a/includes/discovery/sensors/dbm/junos.inc.php b/includes/discovery/sensors/dbm/junos.inc.php
index cc96d8a89f..2d46920251 100644
--- a/includes/discovery/sensors/dbm/junos.inc.php
+++ b/includes/discovery/sensors/dbm/junos.inc.php
@@ -43,7 +43,7 @@ foreach ($pre_cache['junos_oids'] as $index => $entry) {
         $entPhysicalIndex_measured = 'ports';
         discover_sensor($valid['sensor'], 'dbm', $device, $oid, 'tx-' . $index, 'junos', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
     }
-    if (is_numeric($entry['jnxDomCurrentModuleLaneCount']) && $entry['jnxDomCurrentModuleLaneCount'] > 1) {
+    if (isset($entry['jnxDomCurrentModuleLaneCount']) && is_numeric($entry['jnxDomCurrentModuleLaneCount']) && $entry['jnxDomCurrentModuleLaneCount'] > 1) {
         for ($x = 0; $x < $entry['jnxDomCurrentModuleLaneCount']; $x++) {
             $lane = $pre_cache['junos_multilane_oids'][$index . '.' . $x];
             if (is_numeric($lane['jnxDomCurrentLaneRxLaserPower']) && $lane['jnxDomCurrentLaneRxLaserPower'] != 0 && $lane['jnxDomCurrentLaneTxLaserOutputPower'] != 0) {
diff --git a/includes/discovery/sensors/delay/infinera-groove.inc.php b/includes/discovery/sensors/delay/infinera-groove.inc.php
index 97e3a540fa..8da76e05f9 100644
--- a/includes/discovery/sensors/delay/infinera-groove.inc.php
+++ b/includes/discovery/sensors/delay/infinera-groove.inc.php
@@ -25,7 +25,7 @@
  * Modified for DGD, Magnus Bergroth
  */
 foreach ($pre_cache['infineragroove_portTable'] as $index => $data) {
-    if (is_numeric($data['ochOsDGD']) && $data['ochOsDGD'] != 0) {
+    if (isset($data['ochOsDGD']) && is_numeric($data['ochOsDGD']) && $data['ochOsDGD'] != 0) {
         $descr = $data['portAlias'] . ' Differential Group Delay';
         $oid = '.1.3.6.1.4.1.42229.1.2.4.1.19.1.1.22.' . $index;
         $value = $data['ochOsDGD'];
diff --git a/includes/discovery/sensors/entity-sensor.inc.php b/includes/discovery/sensors/entity-sensor.inc.php
index f20537d965..e4c8ec1a46 100644
--- a/includes/discovery/sensors/entity-sensor.inc.php
+++ b/includes/discovery/sensors/entity-sensor.inc.php
@@ -48,6 +48,14 @@ if (! empty($entity_oids)) {
         $low_warn_limit = null;
         $warn_limit = null;
         $high_limit = null;
+        $group = null;
+        $type = null;
+        $oid = null;
+        $descr = null;
+        $divisor = null;
+        $multiplier = null;
+        $current = null;
+        $entPhysicalIndex = null;
 
         // Fix for Cisco ASR920, 15.5(2)S
         if ($entry['entPhySensorType'] == 'other' && Str::contains($entity_array[$index]['entPhysicalName'], ['Rx Power Sensor', 'Tx Power Sensor'])) {
@@ -64,7 +72,7 @@ if (! empty($entity_oids)) {
                 } elseif (count($card) === 4) {
                     $card = $card[0] . $card[1] . '00';
                 }
-                $descr = ucwords($entity_array[$card]['entPhysicalName']) . ' ' . ucwords($entity_array[$index]['entPhysicalDescr']);
+                $descr = ucwords($entity_array[$card]['entPhysicalName'] ?? '') . ' ' . ucwords($entity_array[$index]['entPhysicalDescr'] ?? '');
             } else {
                 $descr = ucwords($entity_array[$index]['entPhysicalName']);
             }
@@ -75,7 +83,13 @@ if (! empty($entity_oids)) {
                 if ($device['os'] === 'arista_eos') {
                     $descr = $entity_array[$index]['entPhysicalDescr'];
                     if (preg_match('/(Input|Output) (voltage|current) sensor/i', $descr) || Str::startsWith($descr, 'Power supply') || preg_match('/^(Power Supply|Hotspot|Inlet|Board)/i', $descr)) {
-                        $descr = ucwords($entity_array[substr_replace($index, '000', -3)]['entPhysicalDescr']) . ' ' . preg_replace('/(Voltage|Current|Power Supply) Sensor$/i', '', ucwords($entity_array[$index]['entPhysicalDescr']));
+                        $descr = (ucwords($entity_array[substr_replace($index, '000', -3)]['entPhysicalDescr'] ?? ''))
+                                 . ' '
+                                 . preg_replace(
+                                      '/(Voltage|Current|Power Supply) Sensor$/i',
+                                      '',
+                                      ucwords($entity_array[$index]['entPhysicalDescr'])
+                                  );
                     }
                     if (preg_match('/(temp|temperature) sensor$/i', $descr)) {
                         $descr = preg_replace('/(temp|temperature) sensor$/i', '', $descr);
@@ -217,7 +231,7 @@ if (! empty($entity_oids)) {
                     // End grouping sensors
                 }
                 $descr = trim($descr);
-                discover_sensor($valid['sensor'], $type, $device, $oid, $index, 'entity-sensor', $descr, $divisor, $multiplier, $low_limit, $low_warn_limit, $warn_limit, $high_limit, $current, 'snmp', $entPhysicalIndex, $entry['entSensorMeasuredEntity'], null, $group);
+                discover_sensor($valid['sensor'], $type, $device, $oid, $index, 'entity-sensor', $descr, $divisor, $multiplier, $low_limit, $low_warn_limit, $warn_limit, $high_limit, $current, 'snmp', $entPhysicalIndex, $entry['entSensorMeasuredEntity'] ?? null, null, $group);
             }
         }//end if
     }//end foreach
diff --git a/includes/discovery/sensors/fanspeed/apc.inc.php b/includes/discovery/sensors/fanspeed/apc.inc.php
index 79276da685..e4af6fa897 100644
--- a/includes/discovery/sensors/fanspeed/apc.inc.php
+++ b/includes/discovery/sensors/fanspeed/apc.inc.php
@@ -25,8 +25,8 @@
 foreach ($pre_cache['cooling_unit_analog'] as $index => $data) {
     $cur_oid = '.1.3.6.1.4.1.318.1.1.27.1.4.1.2.1.3.' . $index;
     $descr = $data['coolingUnitStatusAnalogDescription'];
-    $scale = $data['coolingUnitStatusAnalogScale'];
-    $value = $data['coolingUnitStatusAnalogValue'];
+    $scale = $data['coolingUnitStatusAnalogScale'] ?? null;
+    $value = $data['coolingUnitStatusAnalogValue'] ?? null;
     if (preg_match('/Fan Speed/', $descr) && $data['coolingUnitStatusAnalogUnits'] == '%' && $value >= 0) {
         discover_sensor($valid['sensor'], 'fanspeed', $device, $cur_oid, $cur_oid, 'apc', $descr, $scale, 1, null, null, null, null, $value);
     }
diff --git a/includes/discovery/sensors/gw-eydfa.inc.php b/includes/discovery/sensors/gw-eydfa.inc.php
index 049e05f256..a9d084d334 100644
--- a/includes/discovery/sensors/gw-eydfa.inc.php
+++ b/includes/discovery/sensors/gw-eydfa.inc.php
@@ -79,7 +79,7 @@ foreach (explode("\n", $oids) as $data) {
     unset($oids, $split_oid, $index, $divisor, $descr, $low_limit, $low_warn, $high_warn, $sensor_index);
 }
 
-$oids = snmp_walk($device, 'oaDCPowerTable', '-Osq', 'NSCRTV-HFCEMS-OPTICALAMPLIFIER-MIB');
+$oids = trim(snmp_walk($device, 'oaDCPowerTable', '-Osq', 'NSCRTV-HFCEMS-OPTICALAMPLIFIER-MIB'));
 d_echo($oids . "\n");
 
 if ($oids) {
diff --git a/includes/discovery/sensors/humidity/liebert.inc.php b/includes/discovery/sensors/humidity/liebert.inc.php
index ed4b12f46d..ea46547408 100644
--- a/includes/discovery/sensors/humidity/liebert.inc.php
+++ b/includes/discovery/sensors/humidity/liebert.inc.php
@@ -25,14 +25,14 @@
 $lib_data = snmpwalk_cache_oid($device, 'lgpEnvHumidityEntryRel', [], 'LIEBERT-GP-ENVIRONMENTAL-MIB');
 
 foreach ($lib_data as $index => $data) {
-    if (is_numeric($data['lgpEnvHumidityMeasurementRelTenths'])) {
+    if (isset($data['lgpEnvHumidityMeasurementRelTenths']) && is_numeric($data['lgpEnvHumidityMeasurementRelTenths'])) {
         $oid = '.1.3.6.1.4.1.476.1.42.3.4.2.2.3.1.50.' . $index;
         $low_limit = $data['lgpEnvHumidityLowThresholdRelTenths'];
         $high_limit = $data['lgpEnvHumidityHighThresholdRelTenths'];
         $current = $data['lgpEnvHumidityMeasurementRelTenths'];
         $divisor = 10;
         $new_index = 'lgpEnvHumidityMeasurementRelTenths.' . $index;
-    } elseif (is_numeric($data['lgpEnvHumidityMeasurementRel'])) {
+    } elseif (isset($data['lgpEnvHumidityMeasurementRel']) && is_numeric($data['lgpEnvHumidityMeasurementRel'])) {
         $oid = '.1.3.6.1.4.1.476.1.42.3.4.2.2.3.1.3.' . $index;
         $low_limit = $data['lgpEnvHumidityLowThresholdRel'];
         $high_limit = $data['lgpEnvHumidityHighThresholdRel'];
diff --git a/includes/discovery/sensors/load/infinera-groove.inc.php b/includes/discovery/sensors/load/infinera-groove.inc.php
index ad9e54bf71..b16d4fae2b 100644
--- a/includes/discovery/sensors/load/infinera-groove.inc.php
+++ b/includes/discovery/sensors/load/infinera-groove.inc.php
@@ -23,7 +23,7 @@
  * @author     Nick Hilliard <nick@foobar.org>
  */
 foreach ($pre_cache['infineragroove_slotTable'] as $index => $data) {
-    if (is_numeric($data['cardFanSpeedRate']) && $data['cardFanSpeedRate'] != -99) {
+    if (isset($data['cardFanSpeedRate']) && is_numeric($data['cardFanSpeedRate']) && $data['cardFanSpeedRate'] != -99) {
         $infinera_slot = 'slot-' . str_replace('.', '/', $index);
         $descr = 'Chassis fan ' . $infinera_slot;
         $oid = '.1.3.6.1.4.1.42229.1.2.3.3.1.1.7.' . $index;
diff --git a/includes/discovery/sensors/load/rfc1628.inc.php b/includes/discovery/sensors/load/rfc1628.inc.php
index 6a73a805d1..b9dfb50259 100644
--- a/includes/discovery/sensors/load/rfc1628.inc.php
+++ b/includes/discovery/sensors/load/rfc1628.inc.php
@@ -14,7 +14,7 @@ foreach ($load_data as $index => $data) {
         $value = $data['upsOutputPercentLoad'];
     }
 
-    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'], 'load', $load_oid);
+    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'] ?? 0, 'load', $load_oid);
     $descr = 'Percentage load';
     if (count($load_data) > 1) {
         $descr .= " $index";
diff --git a/includes/discovery/sensors/power/apc.inc.php b/includes/discovery/sensors/power/apc.inc.php
index 3949e174c1..1e5c685b76 100644
--- a/includes/discovery/sensors/power/apc.inc.php
+++ b/includes/discovery/sensors/power/apc.inc.php
@@ -25,8 +25,8 @@
 foreach ($pre_cache['cooling_unit_analog'] as $index => $data) {
     $cur_oid = '.1.3.6.1.4.1.318.1.1.27.1.4.1.2.1.3.' . $index;
     $descr = $data['coolingUnitStatusAnalogDescription'];
-    $scale = $data['coolingUnitStatusAnalogScale'];
-    $value = $data['coolingUnitStatusAnalogValue'];
+    $scale = $data['coolingUnitStatusAnalogScale'] ?? null;
+    $value = $data['coolingUnitStatusAnalogValue'] ?? null;
     if (preg_match('/Cool/', $descr) && $data['coolingUnitStatusAnalogUnits'] == 'kW' && $value >= 0) {
         discover_sensor($valid['sensor'], 'power', $device, $cur_oid, $cur_oid, 'apc', $descr, $scale, 1, null, null, null, null, $value);
     }
diff --git a/includes/discovery/sensors/power/ciscosb.inc.php b/includes/discovery/sensors/power/ciscosb.inc.php
index 2d329db8a1..f21847baa7 100644
--- a/includes/discovery/sensors/power/ciscosb.inc.php
+++ b/includes/discovery/sensors/power/ciscosb.inc.php
@@ -19,7 +19,7 @@ if (is_array($temp)) {
         if (is_numeric($temp[$index]['rlPethPsePortOutputPower']) && $temp[$index]['rlPethPsePortOutputPower'] > 0) {
             $port_descr = get_port_by_index_cache($device['device_id'], preg_replace('/^\d+\./', '', $index));
             $descr = trim($port_descr['ifDescr'] . ' PoE');
-            $highlimit = $temp[$index]['rlPethPsePortOperPowerLimit'] / $divisor;
+            $highlimit = isset($temp[$index]['rlPethPsePortOperPowerLimit']) ? $temp[$index]['rlPethPsePortOperPowerLimit'] / $divisor : null;
             discover_sensor($valid['sensor'], 'power', $device, $cur_oid . $index, $index, 'ciscosb', $descr, $divisor, '1', null, null, null, $highlimit, $temp[$index]['rlPethPsePortOutputPower'] / $divisor, 'snmp', $index);
         }
     }
diff --git a/includes/discovery/sensors/pre-cache/ifotec.inc.php b/includes/discovery/sensors/pre-cache/ifotec.inc.php
index 73cd2e5652..71ca4cf71b 100644
--- a/includes/discovery/sensors/pre-cache/ifotec.inc.php
+++ b/includes/discovery/sensors/pre-cache/ifotec.inc.php
@@ -39,7 +39,6 @@ if (Str::startsWith($device['sysObjectID'], '.1.3.6.1.4.1.21362.100.')) {
 
         // .ifoTemperatureTable.ifoTemperatureEntry.<ifoSysProductIndex>
         $data = snmp_walk($device, 'ifoTemperatureEntry', '-OQn', 'IFOTEC-SMI');
-        var_dump($data);
         foreach (explode(PHP_EOL, $data) as $line) {
             [$oid, $value] = explode(' = ', $line);
 
diff --git a/includes/discovery/sensors/pre-cache/infinera-groove.inc.php b/includes/discovery/sensors/pre-cache/infinera-groove.inc.php
index 0b1dfda25e..43eb23599f 100644
--- a/includes/discovery/sensors/pre-cache/infinera-groove.inc.php
+++ b/includes/discovery/sensors/pre-cache/infinera-groove.inc.php
@@ -22,7 +22,7 @@
  * @copyright  2019 Nick Hilliard
  * @author     Nick Hilliard <nick@foobar.org>
  */
-if (! is_array($pre_cache['infineragroove_portTable'])) {
+if (! isset($pre_cache['infineragroove_portTable']) || ! is_array($pre_cache['infineragroove_portTable'])) {
     echo 'Caching OIDs:';
     $pre_cache['infineragroove_portTable'] = [];
     echo ' portTable';
@@ -44,7 +44,7 @@ foreach (array_keys($pre_cache['infineragroove_portTable']) as $index) {
     unset($indexids);
 }
 
-if (! is_array($pre_cache['infineragroove_slotTable'])) {
+if (! isset($pre_cache['infineragroove_slotTable']) || ! is_array($pre_cache['infineragroove_slotTable'])) {
     $pre_cache['infineragroove_slotTable'] = [];
     echo ' slotTable';
     $pre_cache['infineragroove_slotTable'] = snmpwalk_cache_multi_oid($device, 'slotTable', $pre_cache['infineragroove_slotTable'], 'CORIANT-GROOVE-MIB');
diff --git a/includes/discovery/sensors/pre-cache/ipoman.inc.php b/includes/discovery/sensors/pre-cache/ipoman.inc.php
index 85acd0b187..6858770980 100644
--- a/includes/discovery/sensors/pre-cache/ipoman.inc.php
+++ b/includes/discovery/sensors/pre-cache/ipoman.inc.php
@@ -1,10 +1,10 @@
 <?php
 
 echo 'outletConfigDesc ';
-$pre_cache['ipoman']['out'] = snmpwalk_cache_multi_oid($device, 'outletConfigDesc', $pre_cache['ipoman']['out'], 'IPOMANII-MIB');
+$pre_cache['ipoman']['out'] = snmpwalk_cache_multi_oid($device, 'outletConfigDesc', [], 'IPOMANII-MIB');
 
 echo 'outletConfigLocation ';
 $pre_cache['ipoman']['out'] = snmpwalk_cache_multi_oid($device, 'outletConfigLocation', $pre_cache['ipoman']['out'], 'IPOMANII-MIB');
 
 echo 'inletConfigDesc ';
-$pre_cache['ipoman']['in'] = snmpwalk_cache_multi_oid($device, 'inletConfigDesc', $pre_cache['ipoman']['in'], 'IPOMANII-MIB');
+$pre_cache['ipoman']['in'] = snmpwalk_cache_multi_oid($device, 'inletConfigDesc', [], 'IPOMANII-MIB');
diff --git a/includes/discovery/sensors/snr/infinera-groove.inc.php b/includes/discovery/sensors/snr/infinera-groove.inc.php
index fd2112c274..6393d34791 100644
--- a/includes/discovery/sensors/snr/infinera-groove.inc.php
+++ b/includes/discovery/sensors/snr/infinera-groove.inc.php
@@ -23,7 +23,7 @@
  * @author     Nick Hilliard <nick@foobar.org>
  */
 foreach ($pre_cache['infineragroove_portTable'] as $index => $data) {
-    if (is_numeric($data['ochOsOSNR']) && $data['ochOsOSNR'] != -99) {
+    if (isset($data['ochOsOSNR']) && is_numeric($data['ochOsOSNR']) && $data['ochOsOSNR'] != -99) {
         $descr = $data['portAlias'] . ' Optical SNR';
         $oid = '.1.3.6.1.4.1.42229.1.2.4.1.19.1.1.24.' . $index;
         $value = $data['ochOsOSNR'];
diff --git a/includes/discovery/sensors/state/apc.inc.php b/includes/discovery/sensors/state/apc.inc.php
index 0b587f9df3..d63d9a9a80 100644
--- a/includes/discovery/sensors/state/apc.inc.php
+++ b/includes/discovery/sensors/state/apc.inc.php
@@ -38,8 +38,8 @@ foreach ($cooling_status as $index => $data) {
 
     $tmp_states = explode(',', $data['coolingUnitStatusDiscreteIntegerReferenceKey']);
     $states = [];
-    foreach ($tmp_states as $k => $ref) {
-        preg_match('/([\w]+)\\(([\d]+)\\)/', $ref, $matches);
+    foreach ($tmp_states as $ref) {
+        preg_match('/([\w]+) ?\\(([\d]+)\\)/', $ref, $matches);
         $nagios_state = get_nagios_state($matches[1]);
         $states[] = ['value' => 0, 'generic' => $nagios_state, 'graph' => 0, $matches[2], 'descr' => $matches[1]];
     }
diff --git a/includes/discovery/sensors/state/ciscosb.inc.php b/includes/discovery/sensors/state/ciscosb.inc.php
index 192bcd97fa..729fa0b608 100644
--- a/includes/discovery/sensors/state/ciscosb.inc.php
+++ b/includes/discovery/sensors/state/ciscosb.inc.php
@@ -26,7 +26,7 @@ if (is_array($temp)) {
 
     foreach ($temp as $index => $entry) {
         $port_data = get_port_by_index_cache($device['device_id'], preg_replace('/^\d+\./', '', $index));
-        $descr = trim($port_data['ifDescr'] . ' Suspended Status');
+        $descr = trim(($port_data['ifDescr'] ?? '') . ' Suspended Status');
         if (Str::contains($descr, ['ethernet', 'Ethernet']) && $port_data['ifOperStatus'] !== 'notPresent') {
             //Discover Sensors
             discover_sensor($valid['sensor'], 'state', $device, $cur_oid . $index, $index, $state_name, $descr, 1, 1, null, null, null, null, $temp[$index]['swIfOperSuspendedStatus'], 'snmp', $index);
diff --git a/includes/discovery/sensors/temperature/apc.inc.php b/includes/discovery/sensors/temperature/apc.inc.php
index df8c518988..8bd2b0ba41 100644
--- a/includes/discovery/sensors/temperature/apc.inc.php
+++ b/includes/discovery/sensors/temperature/apc.inc.php
@@ -165,8 +165,8 @@ foreach ($cooling_unit as $index => $data) {
 foreach ($pre_cache['cooling_unit_analog'] as $index => $data) {
     $cur_oid = '.1.3.6.1.4.1.318.1.1.27.1.4.1.2.1.3.' . $index;
     $descr = $data['coolingUnitStatusAnalogDescription'];
-    $scale = $data['coolingUnitStatusAnalogScale'];
-    $value = $data['coolingUnitStatusAnalogValue'];
+    $scale = $data['coolingUnitStatusAnalogScale'] ?? null;
+    $value = $data['coolingUnitStatusAnalogValue'] ?? null;
     if (preg_match('/Temperature/', $descr) && $data['coolingUnitStatusAnalogUnits'] == 'C' && $value >= 0) {
         discover_sensor($valid['sensor'], 'temperature', $device, $cur_oid, $cur_oid, 'apc', $descr, $scale, 1, null, null, null, null, $value);
     }
diff --git a/includes/discovery/sensors/temperature/cisco.inc.php b/includes/discovery/sensors/temperature/cisco.inc.php
index bb5f1d422d..dcd7f93587 100644
--- a/includes/discovery/sensors/temperature/cisco.inc.php
+++ b/includes/discovery/sensors/temperature/cisco.inc.php
@@ -14,6 +14,9 @@ $temp = snmpwalk_cache_multi_oid($device, 'ciscoEnvMonTemperatureStatusTable', [
 if (is_array($temp)) {
     $cur_oid = '.1.3.6.1.4.1.9.9.13.1.3.1.3.';
     foreach ($temp as $index => $entry) {
+        if (! isset($temp[$index]['ciscoEnvMonTemperatureStatusValue'])) {
+            continue;
+        }
         if ($temp[$index]['ciscoEnvMonTemperatureState'] != 'notPresent' && ! empty($temp[$index]['ciscoEnvMonTemperatureStatusDescr'])) {
             $descr = ucwords($temp[$index]['ciscoEnvMonTemperatureStatusDescr']);
             discover_sensor($valid['sensor'], 'temperature', $device, $cur_oid . $index, $index, 'cisco', $descr, '1', '1', null, null, null, $temp[$index]['ciscoEnvMonTemperatureThreshold'], $temp[$index]['ciscoEnvMonTemperatureStatusValue'], 'snmp', $index);
@@ -26,6 +29,6 @@ if (is_array($temp)) {
     $cur_oid = '.1.3.6.1.4.1.9.9.661.1.1.1.12.';
     foreach ($temp as $index => $entry) {
         $descr = snmp_get($device, 'entPhysicalName.' . $index, '-Oqv', 'ENTITY-MIB');
-        discover_sensor($valid['sensor'], 'temperature', $device, $cur_oid . $index, $index, 'cisco', $descr, '1', '1', null, null, null, $temp[$index]['ciscoEnvMonTemperatureThreshold'], $temp[$index]['c3gModemTemperature'], 'snmp', $index);
+        discover_sensor($valid['sensor'], 'temperature', $device, $cur_oid . $index, $index, 'cisco', $descr, '1', '1', null, null, null, $temp[$index]['ciscoEnvMonTemperatureThreshold'] ?? null, $temp[$index]['c3gModemTemperature'], 'snmp', $index);
     }
 }
diff --git a/includes/discovery/sensors/temperature/ciscosb.inc.php b/includes/discovery/sensors/temperature/ciscosb.inc.php
index ca9537da12..de80ccde9f 100644
--- a/includes/discovery/sensors/temperature/ciscosb.inc.php
+++ b/includes/discovery/sensors/temperature/ciscosb.inc.php
@@ -16,10 +16,14 @@ $multiplier = 1;
 $divisor = 1;
 foreach ($pre_cache['ciscosb_rlPhyTestGetResult'] as $index => $ciscosb_data) {
     foreach ($ciscosb_data as $key => $value) {
+        if (! isset($value['rlPhyTestTableTransceiverTemp'])) {
+            continue;
+        }
+
         $oid = '.1.3.6.1.4.1.9.6.1.101.90.1.2.1.3.' . $index . '.5';
         $sensor_type = 'rlPhyTestTableTransceiverTemp';
         $port_descr = get_port_by_index_cache($device['device_id'], preg_replace('/^\d+\./', '', $index));
-        $descr = trim($port_descr['ifDescr'] . ' Module');
+        $descr = trim(($port_descr['ifDescr'] ?? null) . ' Module');
         $temperature = $value['rlPhyTestTableTransceiverTemp'];
         $entPhysicalIndex = $index;
         $entPhysicalIndex_measured = 'ports';
diff --git a/includes/discovery/sensors/temperature/comware.inc.php b/includes/discovery/sensors/temperature/comware.inc.php
index a036085254..13021aac1f 100644
--- a/includes/discovery/sensors/temperature/comware.inc.php
+++ b/includes/discovery/sensors/temperature/comware.inc.php
@@ -59,6 +59,11 @@ $divisor = 1;
 $divisor_alarm = 1000;
 foreach ($pre_cache['comware_oids'] as $index => $entry) {
     if (is_numeric($entry['hh3cTransceiverTemperature']) && $entry['hh3cTransceiverTemperature'] != 2147483647 && isset($entry['hh3cTransceiverDiagnostic'])) {
+        $interface = get_port_by_index_cache($device['device_id'], $index);
+        if ($interface['ifAdminStatus'] != 'up') {
+            continue;
+        }
+
         $oid = '.1.3.6.1.4.1.25506.2.70.1.1.1.15.' . $index;
         $limit_low = $entry['hh3cTransceiverTempLoAlarm'] / $divisor_alarm;
         $warn_limit_low = $entry['hh3cTransceiverTempLoWarn'] / $divisor_alarm;
@@ -67,10 +72,8 @@ foreach ($pre_cache['comware_oids'] as $index => $entry) {
         $current = $entry['hh3cTransceiverTemperature'];
         $entPhysicalIndex = $index;
         $entPhysicalIndex_measured = 'ports';
-        $interface = get_port_by_index_cache($device['device_id'], $index);
-        if ($interface['ifAdminStatus'] == 'up') {
-            $descr = makeshortif($interface['ifDescr']) . ' Module';
-            discover_sensor($valid['sensor'], 'temperature', $device, $oid, 'temp-trans-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
-        }
+
+        $descr = makeshortif($interface['ifDescr']) . ' Module';
+        discover_sensor($valid['sensor'], 'temperature', $device, $oid, 'temp-trans-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
     }
 }
diff --git a/includes/discovery/sensors/temperature/liebert.inc.php b/includes/discovery/sensors/temperature/liebert.inc.php
index 9d698e5cbc..c7867d7efb 100644
--- a/includes/discovery/sensors/temperature/liebert.inc.php
+++ b/includes/discovery/sensors/temperature/liebert.inc.php
@@ -25,17 +25,17 @@
 $lib_data = snmpwalk_cache_oid($device, 'lgpEnvTemperatureEntryDegC', [], 'LIEBERT-GP-ENVIRONMENTAL-MIB');
 
 foreach ($lib_data as $index => $data) {
-    if (is_numeric($data['lgpEnvTemperatureMeasurementTenthsDegC'])) {
+    if (isset($data['lgpEnvTemperatureMeasurementTenthsDegC']) && is_numeric($data['lgpEnvTemperatureMeasurementTenthsDegC'])) {
         $oid = '.1.3.6.1.4.1.476.1.42.3.4.1.3.3.1.50.' . $index;
         $low_limit = $data['lgpEnvTemperatureLowThresholdTenthsDegC'];
         $high_limit = $data['lgpEnvTemperatureHighThresholdTenthsDegC'];
         $current = $data['lgpEnvTemperatureMeasurementTenthsDegC'];
         $divisor = 10;
         $new_index = 'lgpEnvTemperatureMeasurementTenthsDegC.' . $index;
-    } elseif (is_numeric($data['lgpEnvTemperatureMeasurementDegC'])) {
+    } elseif (isset($data['lgpEnvTemperatureMeasurementDegC']) && is_numeric($data['lgpEnvTemperatureMeasurementDegC'])) {
         $oid = '.1.3.6.1.4.1.476.1.42.3.4.1.3.3.1.3.' . $index;
-        $low_limit = $data['lgpEnvTemperatureLowThresholdDegC'];
-        $high_limit = $data['lgpEnvTemperatureHighThresholdDegC'];
+        $low_limit = $data['lgpEnvTemperatureLowThresholdDegC'] ?? null;
+        $high_limit = $data['lgpEnvTemperatureHighThresholdDegC'] ?? null;
         $current = $data['lgpEnvTemperatureMeasurementDegC'];
         $divisor = 1;
         $new_index = 'lgpEnvTemperatureDescrDegC.' . $index;
diff --git a/includes/discovery/sensors/voltage/ciscosb.inc.php b/includes/discovery/sensors/voltage/ciscosb.inc.php
index b1518fad24..7bdb286cb5 100644
--- a/includes/discovery/sensors/voltage/ciscosb.inc.php
+++ b/includes/discovery/sensors/voltage/ciscosb.inc.php
@@ -16,10 +16,14 @@ $multiplier = 1;
 $divisor = 1000000;
 foreach ($pre_cache['ciscosb_rlPhyTestGetResult'] as $index => $ciscosb_data) {
     foreach ($ciscosb_data as $key => $value) {
+        if (! isset($value['rlPhyTestTableTransceiverSupply'])) {
+            continue;
+        }
+
         $oid = '.1.3.6.1.4.1.9.6.1.101.90.1.2.1.3.' . $index . '.6';
         $sensor_type = 'rlPhyTestTableTransceiverSupply';
         $port_descr = get_port_by_index_cache($device['device_id'], preg_replace('/^\d+\./', '', $index));
-        $descr = trim($port_descr['ifDescr'] . ' Supply Voltage');
+        $descr = trim(($port_descr['ifDescr'] ?? null) . ' Supply Voltage');
         $voltage = $value['rlPhyTestTableTransceiverSupply'] / $divisor;
         $entPhysicalIndex = $index;
         $entPhysicalIndex_measured = 'ports';
diff --git a/includes/discovery/sensors/voltage/comware.inc.php b/includes/discovery/sensors/voltage/comware.inc.php
index 236afaf8d0..21dccb415e 100644
--- a/includes/discovery/sensors/voltage/comware.inc.php
+++ b/includes/discovery/sensors/voltage/comware.inc.php
@@ -18,6 +18,11 @@ $divisor = 100;
 $divisor_alarm = 10000;
 foreach ($pre_cache['comware_oids'] as $index => $entry) {
     if (is_numeric($entry['hh3cTransceiverVoltage']) && $entry['hh3cTransceiverVoltage'] != 2147483647 && isset($entry['hh3cTransceiverDiagnostic'])) {
+        $interface = get_port_by_index_cache($device['device_id'], $index);
+        if ($interface['ifAdminStatus'] != 'up') {
+            continue;
+        }
+
         $oid = '.1.3.6.1.4.1.25506.2.70.1.1.1.16.' . $index;
         $limit_low = $entry['hh3cTransceiverVccLoAlarm'] / $divisor_alarm;
         $warn_limit_low = $entry['hh3cTransceiverVccLoWarn'] / $divisor_alarm;
@@ -26,10 +31,8 @@ foreach ($pre_cache['comware_oids'] as $index => $entry) {
         $current = $entry['hh3cTransceiverVoltage'] / $divisor;
         $entPhysicalIndex = $index;
         $entPhysicalIndex_measured = 'ports';
-        $interface = get_port_by_index_cache($device['device_id'], $index);
-        if ($interface['ifAdminStatus'] == 'up') {
-            $descr = makeshortif($interface['ifDescr']) . ' Supply Voltage';
-            discover_sensor($valid['sensor'], 'voltage', $device, $oid, 'volt-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
-        }
+
+        $descr = makeshortif($interface['ifDescr']) . ' Supply Voltage';
+        discover_sensor($valid['sensor'], 'voltage', $device, $oid, 'volt-' . $index, 'comware', $descr, $divisor, $multiplier, $limit_low, $warn_limit_low, $warn_limit, $limit, $current, 'snmp', $entPhysicalIndex, $entPhysicalIndex_measured);
     }
 }
diff --git a/includes/discovery/sensors/voltage/rfc1628.inc.php b/includes/discovery/sensors/voltage/rfc1628.inc.php
index dec23272c2..e87f9b8a3a 100644
--- a/includes/discovery/sensors/voltage/rfc1628.inc.php
+++ b/includes/discovery/sensors/voltage/rfc1628.inc.php
@@ -5,7 +5,7 @@ echo 'RFC1628 ';
 $battery_volts = snmp_get($device, 'upsBatteryVoltage.0', '-OqvU', 'UPS-MIB');
 if (is_numeric($battery_volts)) {
     $volt_oid = '.1.3.6.1.2.1.33.1.2.5.0';
-    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'], 'voltage', $volt_oid);
+    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'] ?? 0, 'voltage', $volt_oid);
 
     discover_sensor(
         $valid['sensor'],
@@ -28,7 +28,7 @@ if (is_numeric($battery_volts)) {
 $output_volts = snmpwalk_group($device, 'upsOutputVoltage', 'UPS-MIB');
 foreach ($output_volts as $index => $data) {
     $volt_oid = ".1.3.6.1.2.1.33.1.4.4.1.2.$index";
-    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'], 'voltage', $volt_oid);
+    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'] ?? 0, 'voltage', $volt_oid);
     $descr = 'Output';
     if (count($output_volts) > 1) {
         $descr .= " Phase $index";
@@ -62,7 +62,7 @@ foreach ($output_volts as $index => $data) {
 $input_volts = snmpwalk_group($device, 'upsInputVoltage', 'UPS-MIB');
 foreach ($input_volts as $index => $data) {
     $volt_oid = ".1.3.6.1.2.1.33.1.3.3.1.3.$index";
-    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'], 'voltage', $volt_oid);
+    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'] ?? 0, 'voltage', $volt_oid);
     $descr = 'Input';
     if (count($input_volts) > 1) {
         $descr .= " Phase $index";
@@ -96,7 +96,7 @@ foreach ($input_volts as $index => $data) {
 $bypass_volts = snmpwalk_group($device, 'upsBypassVoltage', 'UPS-MIB');
 foreach ($bypass_volts as $index => $data) {
     $volt_oid = ".1.3.6.1.2.1.33.1.5.3.1.2.$index";
-    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'], 'voltage', $volt_oid);
+    $divisor = get_device_divisor($device, $pre_cache['poweralert_serial'] ?? 0, 'voltage', $volt_oid);
     $descr = 'Bypass';
     if (count($bypass_volts) > 1) {
         $descr .= " Phase $index";
diff --git a/includes/discovery/storage/cisco-flash.inc.php b/includes/discovery/storage/cisco-flash.inc.php
index 6ad3c129b7..a8997d5ffb 100644
--- a/includes/discovery/storage/cisco-flash.inc.php
+++ b/includes/discovery/storage/cisco-flash.inc.php
@@ -31,7 +31,8 @@ if ($device['os_group'] == 'cisco') {
     foreach ($ciscoFlashPartitionName as $index => $partitionName) {
         $name = array_shift($ciscoFlashDeviceName[$index[0]]) . '(' . array_shift($partitionName) . '):';
         $oids = array('ciscoFlashPartitionSize.' . $index, 'ciscoFlashPartitionFreeSpace.' . $index, 'ciscoFlashPartitionSizeExtended.' . $index, 'ciscoFlashPartitionFreeSpaceExtended.' . $index);
-        $entry = array_shift(snmp_get_multi($device, $oids, '-OQUs', 'CISCO-FLASH-MIB'));
+        $entry = snmp_get_multi($device, $oids, '-OQUs', 'CISCO-FLASH-MIB');
+        $entry = array_shift($entry);
         $storage_size = (Number::cast($entry['ciscoFlashPartitionSize']) === 4294967295 ? $entry['ciscoFlashPartitionSizeExtended'] : $entry['ciscoFlashPartitionSize']);
         $storage_free = (Number::cast($entry['ciscoFlashPartitionFreeSpace']) === 4294967295 ? $entry['ciscoFlashPartitionFreeSpaceExtended'] : $entry['ciscoFlashPartitionFreeSpace']);
         $storage_used = $storage_size - $storage_free;
diff --git a/includes/discovery/storage/hpe-ilo.inc.php b/includes/discovery/storage/hpe-ilo.inc.php
index 4d9b752173..bdba29fd2d 100644
--- a/includes/discovery/storage/hpe-ilo.inc.php
+++ b/includes/discovery/storage/hpe-ilo.inc.php
@@ -9,7 +9,7 @@ if (in_array($device['os'], ['windows', 'hpe-ilo']) || $device['os_group'] == 'u
             $type = $storage['cpqHoFileSysDesc'];
             preg_match_all('/\[.*?:(.*?)\]/', $type, $matches);
 
-            $fstype = $matches[1][0];
+            $fstype = $matches[1][0] ?? null;
             $descr = $storage['cpqHoFileSysDesc'];
             $size = $storage['cpqHoFileSysSpaceTotal'];
             $used = $storage['cpqHoFileSysSpaceUsed'];
diff --git a/includes/discovery/storage/hrstorage.inc.php b/includes/discovery/storage/hrstorage.inc.php
index 426de55f30..ce3a94292e 100644
--- a/includes/discovery/storage/hrstorage.inc.php
+++ b/includes/discovery/storage/hrstorage.inc.php
@@ -32,7 +32,7 @@ if (is_array($hrstorage_array)) {
         $fstype = $storage['hrStorageType'] ?? null;
         $descr = $storage['hrStorageDescr'];
         $storage['hrStorageSize'] = fix_integer_value($storage['hrStorageSize']);
-        $storage['hrStorageUsed'] = fix_integer_value($storage['hrStorageUsed']);
+        $storage['hrStorageUsed'] = isset($storage['hrStorageUsed']) ? fix_integer_value($storage['hrStorageUsed']) : 0;
         $size = ($storage['hrStorageSize'] * $storage['hrStorageAllocationUnits']);
         $used = ($storage['hrStorageUsed'] * $storage['hrStorageAllocationUnits']);
         $units = $storage['hrStorageAllocationUnits'];
diff --git a/includes/discovery/vlans.inc.php b/includes/discovery/vlans.inc.php
index 189394b897..aa224f3efa 100644
--- a/includes/discovery/vlans.inc.php
+++ b/includes/discovery/vlans.inc.php
@@ -44,6 +44,10 @@ if (empty($device['vlans']) === true) {
 foreach ($device['vlans'] as $domain_id => $vlans) {
     foreach ($vlans as $vlan_id => $vlan) {
         // grab the populated data for this vlan
+        if (! isset($per_vlan_data[$vlan_id])) {
+            continue;
+        }
+
         $vlan_data = $per_vlan_data[$vlan_id];
 
         echo "VLAN $vlan_id \n";
@@ -57,21 +61,26 @@ foreach ($device['vlans'] as $domain_id => $vlans) {
 
             $db_w = [
                 'device_id' => $device['device_id'],
-                'port_id'   => $port['port_id'],
+                'port_id'   => $port['port_id'] ?? null,
                 'vlan'      => $vlan_id,
             ];
 
-            $db_a['baseport'] = $index_to_base[$ifIndex];
+            $db_a['baseport'] = $index_to_base[$ifIndex] ?? '';
             $db_a['priority'] = isset($vlan_port['dot1dStpPortPriority']) ? $vlan_port['dot1dStpPortPriority'] : 0;
             $db_a['state'] = isset($vlan_port['dot1dStpPortState']) ? $vlan_port['dot1dStpPortState'] : 'unknown';
             $db_a['cost'] = isset($vlan_port['dot1dStpPortPathCost']) ? $vlan_port['dot1dStpPortPathCost'] : 0;
             $db_a['untagged'] = isset($vlan_port['untagged']) ? $vlan_port['untagged'] : 0;
 
-            echo str_pad($db_a['baseport'], 10) . str_pad($ifIndex, 10) . str_pad($port['ifName'] ?: $port['ifDescr'], 25) . str_pad($db_a['priority'], 10) . str_pad($db_a['state'], 15) . str_pad($db_a['cost'], 10);
+            echo str_pad($db_a['baseport'], 10);
+            echo str_pad($ifIndex, 10);
+            echo str_pad($port['ifName'] ?? $port['ifDescr'] ?? '', 25);
+            echo str_pad($db_a['priority'], 10);
+            echo str_pad($db_a['state'], 15);
+            echo str_pad($db_a['cost'], 10);
 
-            $from_db = dbFetchRow('SELECT * FROM `ports_vlans` WHERE device_id = ? AND port_id = ? AND `vlan` = ?', [$device['device_id'], $port['port_id'], $vlan_id]);
+            $from_db = dbFetchRow('SELECT * FROM `ports_vlans` WHERE device_id = ? AND port_id = ? AND `vlan` = ?', [$device['device_id'], $port['port_id'] ?? null, $vlan_id]);
 
-            if ($from_db['port_vlan_id']) {
+            if ($from_db && $from_db['port_vlan_id']) {
                 $db_id = $from_db['port_vlan_id'];
                 dbUpdate($db_a, 'ports_vlans', '`port_vlan_id` = ?', [$db_id]);
                 echo 'Updated';
diff --git a/includes/discovery/vlans/boss.inc.php b/includes/discovery/vlans/boss.inc.php
index 9a6b37d962..03fbe00106 100644
--- a/includes/discovery/vlans/boss.inc.php
+++ b/includes/discovery/vlans/boss.inc.php
@@ -11,7 +11,7 @@ if ($device['os'] == 'boss') {
 
     foreach ($vlans as $vlan_id => $vlan) {
         d_echo(" $vlan_id");
-        if (is_array($vlans_db[$vtpdomain_id][$vlan_id])) {
+        if (! empty($vlans_db) && is_array($vlans_db[$vtpdomain_id][$vlan_id])) {
             $vlan_data = $vlans_db[$vtpdomain_id][$vlan_id];
             if ($vlan_data['vlan_name'] != $vlan['rcVlanName']) {
                 $vlan_upd['vlan_name'] = $vlan['rcVlanName'];
@@ -43,7 +43,7 @@ if ($device['os'] == 'boss') {
         }
 
         foreach ($egress_ids as $port_id) {
-            $ifIndex = $base_to_index[$port_id - 1]; // -1 fixes off by one error
+            $ifIndex = $base_to_index[$port_id - 1] ?? null; // -1 fixes off by one error
             $per_vlan_data[$vlan_id][$ifIndex]['untagged'] = (in_array($port_id - 1, $untagged_ids) ? 1 : 0); // -1 fixes off by one error
         }
     }
diff --git a/includes/discovery/vlans/cisco-vtp.inc.php b/includes/discovery/vlans/cisco-vtp.inc.php
index 82cdfa0785..8264418012 100644
--- a/includes/discovery/vlans/cisco-vtp.inc.php
+++ b/includes/discovery/vlans/cisco-vtp.inc.php
@@ -18,7 +18,7 @@ if ($device['os_group'] == 'cisco') {
             echo 'VTP Domain ' . $vtpdomain_id . ' ' . $vtpdomain['managementDomainName'] . ' ';
             foreach ($vlans[$vtpdomain_id] as $vlan_id => $vlan) {
                 d_echo(" $vlan_id");
-                if (is_array($vlans_db[$vtpdomain_id][$vlan_id])) {
+                if (isset($vlans_db[$vtpdomain_id][$vlan_id]) && is_array($vlans_db[$vtpdomain_id][$vlan_id])) {
                     $vlan_data = $vlans_db[$vtpdomain_id][$vlan_id];
                     if ($vlan_data['vlan_name'] != $vlan['vtpVlanName']) {
                         $vlan_upd['vlan_name'] = $vlan['vtpVlanName'];
@@ -69,8 +69,8 @@ if ($device['os_group'] == 'cisco') {
                 } else {
                     $vlan_id = $data['vlanTrunkPortNativeVlan'];
                 }
-                $base = $index_to_base[$ifIndex];
-                echo "Vlan: $vlan_id tagged on $base (ifIndex $ifIndex)\n";
+                //$base = $index_to_base[$ifIndex];
+                //echo "Vlan: $vlan_id tagged on $base (ifIndex $ifIndex)\n";
                 $per_vlan_data[$vlan_id][$ifIndex]['untagged'] = 1;
             }
             unset(
diff --git a/includes/discovery/vlans/jetstream.inc.php b/includes/discovery/vlans/jetstream.inc.php
index 84bfb1b90c..ecb00376cd 100644
--- a/includes/discovery/vlans/jetstream.inc.php
+++ b/includes/discovery/vlans/jetstream.inc.php
@@ -69,7 +69,7 @@ if ($vlanversion == 'version1' || $vlanversion == '2') {
     foreach ($jet_vlanDb as $jet_vlan_id => $jet_vlan_data) {
         d_echo(" $jet_vlan_id ");
 
-        if (is_array($vlans_db[$vtpdomain_id][$jet_vlan_id])) {
+        if (isset($vlans_db[$vtpdomain_id][$jet_vlan_id]) && is_array($vlans_db[$vtpdomain_id][$jet_vlan_id])) {
             $vlan_data = $vlans_db[$vtpdomain_id][$jet_vlan_id];
 
             if ($vlan_data['vlan_name'] != $jet_vlan_data['dot1qVlanDescription']) {
@@ -89,7 +89,7 @@ if ($vlanversion == 'version1' || $vlanversion == '2') {
                 'vlan_type' => ['NULL'],
             ], 'vlans');
 
-            log_event('VLAN added: ' . $jet_vlan_data['dot1qVlanDescription'] . ", $vlan_id", $device, 'vlan');
+            log_event('VLAN added: ' . $jet_vlan_data['dot1qVlanDescription'] . ", $jet_vlan_id", $device, 'vlan');
             echo '+';
         }
         $device['vlans'][$vtpdomain_id][$jet_vlan_id] = $jet_vlan_id;
diff --git a/includes/discovery/vlans/q-bridge-mib.inc.php b/includes/discovery/vlans/q-bridge-mib.inc.php
index 3eb360e0b0..a704176f01 100644
--- a/includes/discovery/vlans/q-bridge-mib.inc.php
+++ b/includes/discovery/vlans/q-bridge-mib.inc.php
@@ -81,9 +81,9 @@ if ($vlanversion == 'version1' || $vlanversion == '2') {
         $device['vlans'][$vtpdomain_id][$vlan_id] = $vlan_id; //populate device['vlans'] with ID's
 
         //portmap for untagged ports
-        $untagged_ids = q_bridge_bits2indices($vlan['Q-BRIDGE-MIB::dot1qVlanCurrentUntaggedPorts'] ?? $vlan['Q-BRIDGE-MIB::dot1qVlanStaticUntaggedPorts']);
+        $untagged_ids = q_bridge_bits2indices($vlan['Q-BRIDGE-MIB::dot1qVlanCurrentUntaggedPorts'] ?? $vlan['Q-BRIDGE-MIB::dot1qVlanStaticUntaggedPorts'] ?? '');
         //portmap for members ports (might be tagged)
-        $egress_ids = q_bridge_bits2indices($vlan['Q-BRIDGE-MIB::dot1qVlanCurrentEgressPorts'] ?? $vlan['Q-BRIDGE-MIB::dot1qVlanStaticEgressPorts']);
+        $egress_ids = q_bridge_bits2indices($vlan['Q-BRIDGE-MIB::dot1qVlanCurrentEgressPorts'] ?? $vlan['Q-BRIDGE-MIB::dot1qVlanStaticEgressPorts'] ?? '');
         foreach ($egress_ids as $port_id) {
             if (isset($base_to_index[$port_id])) {
                 $ifIndex = $base_to_index[$port_id];
diff --git a/includes/polling/applications/asterisk.inc.php b/includes/polling/applications/asterisk.inc.php
index dedfb80e7b..66f4378b46 100644
--- a/includes/polling/applications/asterisk.inc.php
+++ b/includes/polling/applications/asterisk.inc.php
@@ -3,6 +3,7 @@
 use LibreNMS\RRD\RrdDefinition;
 
 $name = 'asterisk';
+$app_id = $app->app_id;
 
 if (! empty($agent_data[$name])) {
     $rawdata = $agent_data[$name];
@@ -73,4 +74,4 @@ update_application($app, $rawdata, $asterisk_metrics);
 
 unset($rrd_name, $rrd_def, $iax2_fields, $iax2_tags);
 
-unset($asterisk, $asterisk_metrics, $rawdata); // these are used for all rrds
+unset($asterisk, $asterisk_metrics, $rawdata, $app_id); // these are used for all rrds
diff --git a/includes/polling/cisco-mac-accounting.inc.php b/includes/polling/cisco-mac-accounting.inc.php
index 83c31bed7f..0910be6c3f 100644
--- a/includes/polling/cisco-mac-accounting.inc.php
+++ b/includes/polling/cisco-mac-accounting.inc.php
@@ -55,10 +55,10 @@ if ($device['os_group'] == 'cisco') {
 
                 $mac_entries++;
 
-                $b_in = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedBytes']['input'];
-                $b_out = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedBytes']['output'];
-                $p_in = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedPkts']['input'];
-                $p_out = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedPkts']['output'];
+                $b_in = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedBytes']['input'] ?? null;
+                $b_out = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedBytes']['output'] ?? null;
+                $p_in = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedPkts']['input'] ?? null;
+                $p_out = $cip_array[$ifIndex][$mac]['cipMacHCSwitchedPkts']['output'] ?? null;
 
                 $this_ma = &$cip_array[$ifIndex][$mac];
 
@@ -66,10 +66,10 @@ if ($device['os_group'] == 'cisco') {
                 foreach ($cip_oids as $oid) {
                     foreach (['input', 'output'] as $dir) {
                         $oid_dir = $oid . '_' . $dir;
-                        $acc['update'][$oid_dir] = $this_ma[$oid][$dir];
+                        $acc['update'][$oid_dir] = $this_ma[$oid][$dir] ?? null;
                         $acc['update'][$oid_dir . '_prev'] = $acc[$oid_dir];
                         $oid_prev = $oid_dir . '_prev';
-                        if ($this_ma[$oid][$dir]) {
+                        if (isset($this_ma[$oid][$dir])) {
                             $oid_diff = ($this_ma[$oid][$dir] - $acc[$oid_dir]);
                             $oid_rate = ($oid_diff / $polled_period);
                             $acc['update'][$oid_dir . '_rate'] = $oid_rate;
@@ -79,7 +79,7 @@ if ($device['os_group'] == 'cisco') {
                     }
                 }
 
-                d_echo("\n" . $acc['hostname'] . ' ' . $acc['ifDescr'] . "  $mac -> $b_in:$b_out:$p_in:$p_out ");
+                d_echo("\nDevice id: " . $acc['device_id'] . ' -> ' . $acc['ifDescr'] . "  $mac -> $b_in:$b_out:$p_in:$p_out ");
 
                 $rrd_name = ['cip', $ifIndex, $mac];
                 $rrd_def = RrdDefinition::make()
diff --git a/includes/polling/functions.inc.php b/includes/polling/functions.inc.php
index 3bdb43aeb3..30290f501c 100644
--- a/includes/polling/functions.inc.php
+++ b/includes/polling/functions.inc.php
@@ -75,7 +75,7 @@ function poll_sensor($device, $class)
         if ($sensor['poller_type'] == 'snmp') {
             $mibdir = null;
 
-            $sensor_value = trim(str_replace('"', '', $snmp_data[$sensor['sensor_oid']]));
+            $sensor_value = trim(str_replace('"', '', $snmp_data[$sensor['sensor_oid']] ?? ''));
 
             if (file_exists('includes/polling/sensors/' . $class . '/' . $device['os'] . '.inc.php')) {
                 require 'includes/polling/sensors/' . $class . '/' . $device['os'] . '.inc.php';
diff --git a/includes/polling/ports.inc.php b/includes/polling/ports.inc.php
index d9cefadca6..36b3e4f55d 100644
--- a/includes/polling/ports.inc.php
+++ b/includes/polling/ports.inc.php
@@ -842,19 +842,19 @@ foreach ($ports as $port) {
             $fields = [
                 'INOCTETS' => $this_port['ifInOctets'] ?? null,
                 'OUTOCTETS' => $this_port['ifOutOctets'] ?? null,
-                'INERRORS' => $this_port['ifInErrors'],
-                'OUTERRORS' => $this_port['ifOutErrors'],
+                'INERRORS' => $this_port['ifInErrors'] ?? null,
+                'OUTERRORS' => $this_port['ifOutErrors'] ?? null,
                 'INUCASTPKTS' => $this_port['ifInUcastPkts'] ?? null,
                 'OUTUCASTPKTS' => $this_port['ifOutUcastPkts'] ?? null,
                 'INNUCASTPKTS' => $this_port['ifInNUcastPkts'] ?? null,
                 'OUTNUCASTPKTS' => $this_port['ifOutNUcastPkts'] ?? null,
-                'INDISCARDS' => $this_port['ifInDiscards'],
-                'OUTDISCARDS' => $this_port['ifOutDiscards'],
+                'INDISCARDS' => $this_port['ifInDiscards'] ?? null,
+                'OUTDISCARDS' => $this_port['ifOutDiscards'] ?? null,
                 'INUNKNOWNPROTOS' => $this_port['ifInUnknownProtos'] ?? null,
-                'INBROADCASTPKTS' => $this_port['ifInBroadcastPkts'],
-                'OUTBROADCASTPKTS' => $this_port['ifOutBroadcastPkts'],
-                'INMULTICASTPKTS' => $this_port['ifInMulticastPkts'],
-                'OUTMULTICASTPKTS' => $this_port['ifOutMulticastPkts'],
+                'INBROADCASTPKTS' => $this_port['ifInBroadcastPkts'] ?? null,
+                'OUTBROADCASTPKTS' => $this_port['ifOutBroadcastPkts'] ?? null,
+                'INMULTICASTPKTS' => $this_port['ifInMulticastPkts'] ?? null,
+                'OUTMULTICASTPKTS' => $this_port['ifOutMulticastPkts'] ?? null,
             ];
 
             // non rrd stats (will be filtered)
diff --git a/includes/polling/ports/os/airos-af-ltu.inc.php b/includes/polling/ports/os/airos-af-ltu.inc.php
index 9a1b400284..3e5f7aebc6 100644
--- a/includes/polling/ports/os/airos-af-ltu.inc.php
+++ b/includes/polling/ports/os/airos-af-ltu.inc.php
@@ -28,10 +28,10 @@ foreach ($port_stats as $index => $afport_stats) {
     if ($afport_stats['ifDescr'] == 'eth0') {
         if (isset($airos_stats[0]['afLTUethConnected'])) {
             $port_stats[$index]['ifOperStatus'] = ($airos_stats[0]['afLTUethConnected'] == 'connected' ? 'up' : 'down');
-            $port_stats[$index]['ifHCInOctets'] = $airos_stats[0]['afLTUethRxBytes'];
-            $port_stats[$index]['ifHCOutOctets'] = $airos_stats[0]['afLTUethTxBytes'];
-            $port_stats[$index]['ifHCInUcastPkts'] = $airos_stats[0]['afLTUethRxPps'];
-            $port_stats[$index]['ifHCOutUcastPkts'] = $airos_stats[0]['afLTUethTxPps'];
+            $port_stats[$index]['ifHCInOctets'] = $airos_stats[0]['afLTUethRxBytes'] ?? null;
+            $port_stats[$index]['ifHCOutOctets'] = $airos_stats[0]['afLTUethTxBytes'] ?? null;
+            $port_stats[$index]['ifHCInUcastPkts'] = $airos_stats[0]['afLTUethRxPps'] ?? null;
+            $port_stats[$index]['ifHCOutUcastPkts'] = $airos_stats[0]['afLTUethTxPps'] ?? null;
             $port_stats[$index]['ifHighSpeed'] = '1000';
         } else {
             /**
diff --git a/includes/polling/ports/os/ciena-sds.inc.php b/includes/polling/ports/os/ciena-sds.inc.php
index ea13507641..365cba9d88 100644
--- a/includes/polling/ports/os/ciena-sds.inc.php
+++ b/includes/polling/ports/os/ciena-sds.inc.php
@@ -38,6 +38,11 @@ if (in_array($device['hardware'], $bad_HC_counter_devices)) {
         // PM index for port 1/1 -- 1000001
         // if index for port 1/1 --  100001
 
+        // Ignore ports with index of example 61.1000001
+        if (Str::contains($index, '.')) {
+            continue;
+        }
+
         $nms_index = $index - 900000;
 
         if (isset($port_stats[$nms_index])) {
diff --git a/includes/polling/ports/os/infinera-groove.inc.php b/includes/polling/ports/os/infinera-groove.inc.php
index 09be4a4291..4d447b284f 100644
--- a/includes/polling/ports/os/infinera-groove.inc.php
+++ b/includes/polling/ports/os/infinera-groove.inc.php
@@ -29,7 +29,7 @@ foreach (['eth100g', 'eth40g', 'eth10g', 'fc16g', 'fc8g'] as $infineratype) {
     preg_match('/[a-z]+(\d+)g/i', $infineratype, $matches);
     $infspeed = $matches[1];
 
-    $cg_stats = snmpwalk_cache_multi_oid($device, $infineratype . 'Entry', $cg_stats, 'CORIANT-GROOVE-MIB');
+    $cg_stats = snmpwalk_cache_multi_oid($device, $infineratype . 'Entry', [], 'CORIANT-GROOVE-MIB');
     $cg_stats = snmpwalk_cache_multi_oid($device, $infineratype . 'Statistics', $cg_stats, 'CORIANT-GROOVE-MIB');
 
     $required = [
diff --git a/includes/polling/storage/cisco-flash.inc.php b/includes/polling/storage/cisco-flash.inc.php
index f2a092a23e..c38d8dfb35 100644
--- a/includes/polling/storage/cisco-flash.inc.php
+++ b/includes/polling/storage/cisco-flash.inc.php
@@ -26,7 +26,8 @@
 use LibreNMS\Util\Number;
 
 $oids = array('ciscoFlashPartitionSize.' . $storage['storage_index'], 'ciscoFlashPartitionFreeSpace.' . $storage['storage_index'], 'ciscoFlashPartitionSizeExtended.' . $storage['storage_index'], 'ciscoFlashPartitionFreeSpaceExtended.' . $storage['storage_index']);
-$entry = array_shift(snmp_get_multi($device, $oids, '-OQUs', 'CISCO-FLASH-MIB'));
+$entry = snmp_get_multi($device, $oids, '-OQUs', 'CISCO-FLASH-MIB');
+$entry = array_shift($entry);
 $storage['size'] = (Number::cast($entry['ciscoFlashPartitionSize']) === 4294967295 ? $entry['ciscoFlashPartitionSizeExtended'] : $entry['ciscoFlashPartitionSize']);
 $storage['free'] = (Number::cast($entry['ciscoFlashPartitionFreeSpace']) === 4294967295 ? $entry['ciscoFlashPartitionFreeSpaceExtended'] : $entry['ciscoFlashPartitionFreeSpace']);
 $storage['used'] = $storage['size'] - $storage['free'];
diff --git a/includes/polling/storage/hrstorage.inc.php b/includes/polling/storage/hrstorage.inc.php
index 84c42017cb..abf24345b4 100644
--- a/includes/polling/storage/hrstorage.inc.php
+++ b/includes/polling/storage/hrstorage.inc.php
@@ -9,7 +9,7 @@ if (! isset($storage_cache['hrstorage'])) {
 $entry = $storage_cache['hrstorage'][$storage['storage_index']];
 
 $storage['units'] = $entry['hrStorageAllocationUnits'];
-$entry['hrStorageUsed'] = fix_integer_value($entry['hrStorageUsed']);
+$entry['hrStorageUsed'] = fix_integer_value($entry['hrStorageUsed'] ?? 0);
 $entry['hrStorageSize'] = fix_integer_value($entry['hrStorageSize']);
 $storage['used'] = ($entry['hrStorageUsed'] * $storage['units']);
 $storage['size'] = ($entry['hrStorageSize'] * $storage['units']);
diff --git a/includes/port-descr-parser.inc.php b/includes/port-descr-parser.inc.php
index e55ad510fc..f8ad231532 100644
--- a/includes/port-descr-parser.inc.php
+++ b/includes/port-descr-parser.inc.php
@@ -8,9 +8,10 @@ echo $this_port['ifAlias'];
 $split = preg_split('/[:\[\]{}()]/', $this_port['ifAlias']);
 $type = isset($split[0]) ? trim($split[0]) : null;
 $descr = isset($split[1]) ? trim($split[1]) : null;
-$circuit = trim(preg_split('/[{}]/', $this_port['ifAlias'])[1]) ?? null;
-$notes = trim(preg_split('/[()]/', $this_port['ifAlias'])[1]) ?? null;
-$speed = preg_split('/[\[\]]/', $this_port['ifAlias'])[1] ?? null;
+
+$circuit = trim(preg_split('/[{}]/', $this_port['ifAlias'])[1] ?? '');
+$notes = trim(preg_split('/[()]/', $this_port['ifAlias'])[1] ?? '');
+$speed = trim(preg_split('/[\[\]]/', $this_port['ifAlias'])[1] ?? '');
 
 if ($type && $descr) {
     $type = strtolower($type);